NEEDLE SELECTOR DEVICE

Abstract

 This invention relates to a needle selector to behave at a higher speed that can narrow a gap further between fingers in the vertical direction.
Driving means generates driving force to cause displacement between two first positions on a first arc in a given plane. A finger includes a subject part to receive the driving force and an action part to act on a working needle or a jack. The action part is formed to be opposite the subject part. The subject part is formed into a cam. In response to application of the driving force to the subject part resulting from displacement to one of the first positions, the action part is displaced to one of two second positions on a second arc in the plane having a chord extending in a direction crossing the direction of the chord of the first arc..

Description

Technical Field

[0001] This invention relates to a needle selector, particularly to a needle selector for a knitting machine.

Background Art

[0002] A needle selector for transmitting a pattern forming procedure stored in a storage to up-and-down motion of a working needle has been used recently for a knitting machine. To meet request for lower cost and a higher speed in the textile industry, a needle selector for a knitting machine with a sliding or swinging finger has been developed. A piezoelectric driver using a piezoelectric element featuring a high response speed and low power consumption has been used as a driver of a needle selector for a knitting machine.

[0003] According to a conventional structure, a jack is buried in a rotary cylinder, the jack moves up and down along a groove in the cylinder, a general polar solenoid is used, and an actuating plate is made to come closer to or get away from the cylinder in the direction of an arrow Q based on the direction of a current flowing in a coil (see patent literature 1, for example)

[0004] There has also been a structure where a plate is moved up and down in a curved pattern by a piezoelectric element and a finger to follow this movement moves up and down accordingly (see patent literature 2, for example).

[0005] Meanwhile, a displacement amplifying mechanism has been used to realize an actuator using a piezoelectric element to be deformed in the D33 mode.

[0006] A conventional displacement amplifying mechanism for amplification of displacement in a uniaxial direction output from a driving member such as a piezoelectric element includes: multiple levers arranged in a direction where the displacement is transmitted; a fixing part that supports these levers; an elastically deformable fulcrum coupling part that forms the fulcrums of the levers; and an elastically deformable point of effort coupling part that forms the points of effort of the levers (see patent literature 3, for example).

[0007] The displacement amplifying mechanism may include a displacement amplifying motion part that makes displacement amplifying motion of amplifying displacement by the expansion and contraction of a piezoelectric element, and a compression coil spring provided to a portion where displacement generated therein is larger than the displacement by the expansion and contraction of the piezoelectric element generated in the displacement amplifying motion part. The compression coil spring applies compression force to the piezoelectric element in response to the displacement amplifying motion by the displacement amplifying motion part when the piezoelectric element expands and contracts.

Citation List

Patent Literature

[0008] 

Patent Literature 1: Japanese Patent Application Publication No. Hei 1-61542 (Fig. 9)

Patent literature 2: Publication of International Application No. 2005/106088 (Figs. 1 and 2)

Patent Literature 3: Japanese Patent Application Publication No. 2008-96931

Patent Literature 4: Japanese Patent Application Publication No. 2008-99399

Summary of Invention

Technical Problem

[0009] In order to move fingers up and down, not only the widths of the fingers but also displacements resulting from up-and-down motions should been allowed for in determining a gap (pitch) between the fingers in the vertical direction.

[0010] According to the structure disclosed in patent literature 1, the solenoid can make the actuating plate come closer to or get away from the cylinder. Meanwhile, a portion of a larger mass moves a longer distance linearly, so that motion is allowed only at a low speed.

[0011] The displacement amplifying mechanism has a large width relative to a direction of displacement. Thus, it has not been allowed to use the displacement amplifying mechanism in a needle selector for a knitting machine.

[0012] The piezoelectric element to be deformed in the D33 mode can expand and contract at a higher speed. However, a small amount of displacement of this piezoelectric element hinders use of this piezoelectric element in a needle selector for a knitting machine.

[0013] This invention has been made in view of the aforementioned circumstances. This invention is intended to allow behavior at a higher speed and to narrow a gap further between fingers in the vertical direction. This invention is also intended to reduce a width further to allow behavior at a higher speed.

Solution to Problem

[0014] A needle selector according to one aspect of this invention is for a knitting machine The needle selector includes: driving means that generates driving force to cause displacement between two first positions on a first arc in a predetermined plane; and a finger including a subject part to receive the driving force and an action part to act on a working needle or a jack. The action part is formed to be opposite to the subject part. The subject part is formed as a cam. In response to application of the driving force to the subject part resulting from displacement to one of the first positions, the action part is displaced to one of two second positions on a second arc formed in the predetermined plane and having a chord extending in a direction crossing the direction of the chord of the first arc..

[0015] The predetermined plane can be perpendicular to a moving direction of the working needle when selected.

[0016] The driving means can generate the driving force using deformation of a piezoelectric element.

[0017] The driving means can generate the driving force using deformation of the piezoelectric element in the D33 mode..

[0018] The driving means can generate the driving force using deformation of the piezoelectric element of a bimorph type.

[0019] The driving means can generate the driving force using deformation of a magnetostrictive element

[0020] The driving means can generate the driving force using a solenoid actuator.

[0021] The driving means can generate the driving force using deformation of a shape-memory alloy.

[0022] The driving means can include a position holding unit. The position holding unit holds the finger for the action part being in one of the second positions where the action part acts on the working needle or the jack and receives force applied to the finger for displacement of the working needle, when the action part of the finger is to act to displace the working needle

[0023] The position holding unit of the driving means can avoid interference with displacement of the finger if the working needle is not to be displaced.

[0024] The driving means can include a displacement amplifying unit that amplifies displacement generated by a driving member and generates the driving force to cause displacement between the first positions on the first arc in the plane.

[0025] According to one aspect of this invention, the driving force is generated that causes displacement between the two first positions on the first arc in the given plane. The finger includes the subject part to receive the driving force and the action part to act on the working needle or the jack. The action part is formed to be opposite the subject part. In response to application of the driving force to the subject part formed into a cam resulting from displacement to one of the first positions, the action part is displaced to one of the two second positions on the second arc in the plane having a chord extending in the direction crossing the direction of the chord of the first arc.

Advantageous Effects of Invention

[0026] As described above, one aspect of this invention achieves behavior at a higher speed and can narrow a gap further between fingers in the vertical direction.

Brief Description of Drawings

[0027] 

Fig. 1 is a perspective view showing an exemplary appearance of a needle selector 11 according to an embodiment of this invention.

Fig 2 is a top view showing the exemplary appearance of the needle selector 11 according to the embodiment of this invention.

Fig.. 3 is a front view showing the exemplary appearance of the needle selector 11 according to the embodiment of this invention.

Fig. 4 is a right side view showing the exemplary appearance of the needle selector 11 according to the embodiment of this invention.

Fig 5 is a bottom view showing the exemplary appearance of the needle selector 11 according to the embodiment of this invention.

Fig. 6 is a perspective view showing an internal structure of the needle selector 11.

Fig. 7 is a perspective view showing the structure of a finger 21-1 and that of a driving unit 31-1 in detail.

Fig. 8 is a top view drawn by orthographic projection showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail.

Fig. 9 is a front view drawn by orthographic projection showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail.

Fig. 10 is a right side view drawn by orthographic projection showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail.

Fig. 11 is a back view drawn by orthographic projection showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail.

Fig 12 is a perspective view showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail.

Fig. 13 is a top view showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail.

Fig. 14 is a perspective view showing an exemplary appearance of a needle selector 101 according to an embodiment of this invention

Fig. 15 is a top view showing the exemplary appearance of the needle selector 101 according to the embodiment of this invention.

Fig. 16 is a front view showing the exemplary appearance of the needle selector 101 according to the embodiment of this invention.

Fig. 17 is a right side view showing the exemplary appearance of the needle selector 101 according to the embodiment of this invention.

Fig. 18 is a bottom view showing the exemplary appearance of the needle selector 101 according to the embodiment of this invention.

Fig. 19 is a back view showing the exemplary appearance of the needle selector 101 according to the embodiment of this invention

Fig. 20 is a perspective view showing an internal structure of the needle selector 101.

Fig. 21 is a top view showing the internal structure of the needle selector 101.

Fig. 22 is a right side view showing the internal structure of the needle selector 101.

Fig. 23 is an enlarged top view showing the structure of a finger 121-4 and that of a latching unit 142-4 in detail.

Fig. 24 is an enlarged top view showing the structure of the finger 121-4 and that of the latching unit 142-4 in detail. Description of Embodiments

[0028] Figs. 1 to 5 show an exemplary appearance of a needle selector 11 according to an embodiment of this invention. Fig. 1 is a perspective view showing the exemplary appearance of the needle selector 11. Figs. 2, 3, 4, and 5 are a top view, a front view, a right side view, and a bottom view respectively showing the exemplary appearance of the needle selector 11. A left side view showing the exemplary appearance of the needle selector 11 is to include a shape symmetric to the shape of the right side view of Fig 4, so that this left side view will not be shown.

[0029] In the drawings, a lengthwise direction referred to below with respect to the needle selector 11 is indicated by a Y axis, a vertical direction is indicated by a Z axis, and a lateral direction is indicated by an X axis. In the below, the left side of the X-axis direction of Fig. 3 is simply called a left side whereas the right side of the X-axis direction of Fig. 3 is simply called aright side. In the below, the front side of the Y-axis direction of Fig. 3 is simply called a front side whereas the rear side of the Y-axis direction of Fig 3 is simply called a rear side. In the below, the upper side of the Z-axis direction of Fig. 3 is simply called an upper side whereas the lower side of the Z-axis direction of Fig. 3 is simply called a lower side.

[0030] The needle selector 11 is attached to a knitting machine such as a weft knitting machine or a warp knitting machine that is for example a horizontal knitting machine or a hosiery knitting machine. In the below, the needle selector 11 is to be attached for example to a circular knitting machine The needle selector 11 makes a working needle behave in a manner responsive to a pattern.. To achieve this, the needle selector 11 selects the behavior of the working needle. Covers are provided to the upper surface, the front, the right side surface, and the left side surface of the needle selector 11. The bottom surface of the needle selector 11 is provided with a groove to be used for positioning at the knitting machine when the needle selector 11 is attached to the knitting machine.

[0031] The needle selector 11 is provided with fingers 21-1 to 21-4. The fingers 21-1 to 21-4 select the behavior of the working needle according to positions where the fingers 21-1 to 21-4 are displaced.

[0032] The fingers 21-1 to 21-4 are each displaced so as to project through a hole in the cover on the front of the needle selector 11 or go inside the cover on the front of the needle selector 11. Specifically, the fingers 21-1 to 21-4 each move to the front or rear side. When moving to the front side, the fingers 21-1 to 21-4 press or lift the approaching working needle or a jack When moving to the rear side, the fingers 21-1 to 21-4 let the working needle or the jack pass therethrough. The jack is arranged below the working needle, for example. The jack is a member that transmits selective motion to the working needle.

[0033] The fingers 21-1 to 21-4 have the same shape. The finger 21-1 is arranged at the bottom.. The fingers 21-2, 21-3, and 21-4 are arranged in this order above the finger 21-1. The fingers 21-1 to 21-4 are arranged so as to overlap in the Z-axis direction, specifically so as to be placed in the same positions in the X-axis direction and the Y-axis direction.

[0034] Adjacent ones of the fingers 21-1 to 21-4 are spaced by a gap (hereinafter called a pitch) that is constant in the vertical direction (Z-axis direction). Reducing the pitch can shorten a length in the vertical direction (Z-axis direction) required for arrangement of the fingers 21-1 to 21-4 With the same length, reducing the pitch allows arrangement of a larger number of fingers, thereby enhancing the production capacity of the knitting machine. Thus, making the pitch smaller is preferable.

[0035] The dimension of each of the fingers 21-1 to 21-4 in the Z-axis direction is smaller than the pitch. Specifically, each of the fingers 21-1 to 21-4 is thinner than the pitch.

[0036] In consideration of placing the needle selector 11 adjacent to the knitting machine during attachment of the needle selector 11, it is preferable that the width of the needle selector 11, specifically the dimension of the needle selector 11 in the X-axis direction be made smaller.

[0037] Fig. 6 is a perspective view showing an internal structure of the needle selector 11. Driving units 31-1 to 31-4 are arranged inside the needle selector 11 so as to overlap in the Z-axis direction on a base 32 arranged on the bottom surface of the needle selector 11, specifically so as to be placed in the same positions in the X-axis direction and the Y-axis direction. The driving units 31-1 to 31-4 drive the fingers 21-1 to 21-4 respectively. The base 32 functions as a foundation of the needle selector 11 to which the driving units 31-1 to 31-4 and the fingers 21-1 to 21-4 are fixed.

[0038] More specifically, the fingers 21-1 to 21-4, piezoelectric elements 41-1 to 41-4, displacement amplifying units 42-1 to 42-4, a pin 43, a pin 44, latching units 45-1 to 45-4, a pin 46, a pin 47, and a pin 48 are provided inside the needle selector 11

[0039] The driving unit 31-1 is formed of the piezoelectric element 41-1, the pins 43 and 44, the displacement amplifying unit 42-1, the latching unit 45-1, and the pin 46. The driving unit 31-2 is formed of the piezoelectric element 41-2, the pins 43 and 44, the displacement amplifying unit 42-2, the latching unit 45-2, and the pin 46. The driving unit 31-3 is formed of the piezoelectric element 41-3, the pins 43 and 44, the displacement amplifying unit 42-3, the latching unit 45-3, and the pin 46. The driving unit 31-4 is formed of the piezoelectric element 41-4, the pins 43 and 44, the displacement amplifying unit 42-4, the latching unit 45-4, and the pin 46.

[0040] The piezoelectric elements 41-1 to 41-4 have the same shape.. The displacement amplifying units 42-1 to 42-4 have the same shape.. The latching units 45-1 to 45-4 have the same shape.

[0041] The piezoelectric element 41-1, the displacement amplifying unit 42-1 and the latching unit 45-1 forming the driving unit 31-1, and the finger 21-1 are arranged in a plane (hereinafter called a horizontal plane 1) parallel to a horizontal plane defined by the X axis and the Y axis.. The piezoelectric element 41-1, the displacement amplifying unit 42-1, and the latching unit 45-1 forming the driving unit 31-1 have respective dimensions in the Z-axis direction smaller than the pitch. Specifically, the piezoelectric element 41-1, the displacement amplifying unit 42-1, and the latching unit 45-1 are thinner than the pitch.

[0042] The piezoelectric element 41-2, the displacement amplifying unit 42-2 and the latching unit 45-2 forming the driving unit 31-2, and the finger 21-2 are arranged in a plane (hereinafter called a horizontal plane 2) parallel to the horizontal plane 1 and spaced above the horizontal plane 1 by the pitch. The piezoelectric element 41-3, the displacement amplifying unit 42-3 and the latching unit 45-3 forming the driving unit 31-3, and the finger 21-3 are arranged in a plane (hereinafter called a horizontal plane 3) parallel to the horizontal plane 2 and spaced above the horizontal plane 2 by the pitch. The piezoelectric element 41-4, the displacement amplifying unit 42-4 and the latching unit 45-4 forming the driving unit 31-4, and the finger 21-4 are arranged in a plane (hereinafter called a horizontal plane 4) parallel to the horizontal plane 3 and spaced above the horizontal plane 3 by the pitch.. The piezoelectric element 41-2, the displacement amplifying unit 42-2, and the latching unit 45-2 forming the driving unit 31-2 are thinner than the pitch. The piezoelectric element 41-3, the displacement amplifying unit 42-3, and the latching unit 45-3 forming the driving unit 31-3 are thinner than the pitch. The piezoelectric element 41-4, the displacement amplifying unit 42-4, and the latching unit 45-4 forming the driving unit 31-4 are thinner than the pitch.

[0043] The fingers 21-1 to 21-4, the piezoelectric elements 41-1 to 41-4, the displacement amplifying units 42-1 to 42-4, and the latching units 45-1 to 45-4 are thinner than the pitch. Thus, by stacking the fingers 21-1 to 21-4 and stacking the driving units 31-1 to 31-4, the fingers 21-1 to 21-4 and the driving units 31-1 to 31-4 can be spaced by the given pitch.

[0044] The horizontal planes 1 to 4 are perpendicular to a direction where a working needle to be selected moves when the needle selector 11 is attached to the circular knitting machine used as a knitting machine.

[0045] The piezoelectric elements 41-1 to 41-4 are examples of driving elements or driving members. The piezoelectric elements 41-1 to 41-4 are stacked piezoelectric elements and expand and contract in the Y-axis direction in response to application of a voltage. Specifically, the piezoelectric elements 41-1 to 41-4 are deformed in the D33 mode according to which the piezoelectric element 41-1 to 41-4 change in the same direction in response to an applied electric field. In other words, the piezoelectric elements 41-1 to 41-4 output displacement in a uniaxial direction responsive to the quantity of input energy

[0046] The piezoelectric elements 41-1 to 41-4 are attached inside the displacement amplifying units 42-1 to 42-4 respectively so as to be placed in the horizontal planes 1 to 4 respectively. Thus, before and after being deformed in response to application of a voltage, respective opposite ends of the piezoelectric elements 41-1 to 41-4 are placed in the horizontal planes 1 to 4 respectively

[0047] The displacement amplifying units 42-1 to 42-4 are what are called displacement amplifying mechanisms. The displacement amplifying units 42-1 to 42-4 are each formed into a substantially flat plate. The displacement amplifying units 42-1 to 42-4 are formed to be smaller in width (dimensions in the X-axis direction). The displacement amplifying units 42-1 to 42-4 amplify displacements generated at the piezoelectric elements 41-1 to 41-4 respectively and generate driving forces for displacements in the horizontal planes 1 to 4 respectively. Specifically, the displacement amplifying units 42-1 to 42-4 amplify displacements output from the piezoelectric elements 41-1 to 41-4 respectively.

[0048] The displacement amplifying units 42-1 to 42-4 are fixed to the base 32 with the pins 43 and 44. Driving forces generated by the displacement amplifying units 42-1 to 42-4 are transmitted to the latching units 45-1 to 45-4 respectively.

[0049] The latching units 45-1 to 45-4 are each formed into a bar. The latching units 45-1 to 45-4 are fixed to the base 32 with the pin 46 in a manner that allows the latching units 45-1 to 45-4 to rotate freely.. If one end of each of the latching units 45-1 to 45-4 is displaced by a corresponding one of the displacement amplifying units 42-1 to 42-4, each of the latching units 45-1 to 45-4 rotates about the pin 46. Respective opposite ends of the latching units 45-1 to 45-4 rotating about the pin 46 press the fingers 21-1 to 21-4, thereby transmitting driving forces to the fingers 21-1 to 21-4 respectively.

[0050] The fingers 21-1 to 21-4 are fixed to the base 32 in a manner that allows the fingers 21-1 to 21-4 to rotate freely about the pin 47. The pin 48 makes abutting contacts with the fingers 21-1 to 21-4, thereby restricting the respective positions of the fingers 21-1 to 21-4 when the fingers 21-1 to 21-4 move to the front side.

[0051] As described above, the fingers 21-1 to 21-4 have the same structure and are stacked in the vertical direction. The driving units 31-1 to 31-4 have the same structure and are stacked in the vertical direction.

[0052] The structure of the finger 21-1 and that of the driving unit 31-1 are described in detail next by referring to Figs. 7 to 13. In Figs 7 to 13, only those parts including the pins 43, 44, 46, 47 and 48 necessary for the behavior of the finger 21-1 and that of the driving unit 31-1 are shown. In the below, the description of the pins 43, 44, 46, 47 and 48 given by referring to Figs. 7 to 13 relates only to the behavior of the finger 21-1 and that of the driving unit 31-1.

[0053] Fig. 7 is a perspective view showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail. Figs 8 to 11 are views drawn by orthographic projection showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail Figs. 8, 9, 10, and 11 are a top view, a front view, a right side view, and a back view respectively. Figs. 7 to 11 show the finger 21-1 and the driving unit 31-1 while the finger 21-1 has moved to the front side.

[0054] Fig. 12 is a perspective view showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail. Fig.. 13 is a top view showing the structure of the finger 21-1 and that of the driving unit 31-1 in detail. Figs. 12 and 13 show the finger 21-1 and the driving unit 31-1 while the finger 21-1 has moved to the rear side

[0055] The displacement amplifying unit 42-1, the latching unit 45-1, and the finger 21-1 are each made of a metallic material integrally. Each of the displacement amplifying unit 42-1, the latching unit 45-1, and the finger 21-1 can be made of resin such as engineering plastic or a composite material such as fiber-reinforced plastic. Each of the displacement amplifying unit 42-1, the latching unit 45-1, and the finger 21-1 can be molded by pressing, cutting, casting, injection molding or metallic powder injection molding, or a combination of these processes.

[0056] The displacement amplifying unit 42-1 is formed of a base part 61, a base part 62, a driving element fixing end 63, a driving element fixing end 64, a first point of effort coupling part 65, a first fulcrum beam 66, a first fulcrum coupling part 67, a second fulcrum beam 68, a second fulcrum coupling part 69, a second point of effort coupling part 70, a displacement beam 71, a displacement end position adjusting part 72, and a displacement end 73. The latching unit 45-1 is formed of a subject end 81, a hinge part 82, a beam 83, and a displacement end 84 The finger 21-1 is formed of an abutting part 91, a cam-like part 92, an angle regulating part 93, a projection 94, and a recess 95.

[0057] The structure of the displacement amplifying unit 42-1 is described first.

[0058] The base part 61 forms a part of the displacement amplifying unit 42-1 close to the finger 21-1 and is formed into a substantially rectangular shape while placing the displacement end position adjusting part 72 and the displacement end 73 between the base part 61 and the latching unit 45-1. The base part 61 is arranged on the side of an end portion of the piezoelectric element 41-1 where the piezoelectric element 41-1 as a driving member is displaced. The base part 61 receives force resulting from the displacement of the driving member. The base part 61 is fixed to the base 32 with the pins 43 and 44 spaced by a given gap in the X-axis direction and passing through the base part 61 The base part 61 is not displaced relative to the base 32 by the expansion and contraction of the piezoelectric element 41-1. Specifically, the base part 61 is fixed to the needle selector 11.

[0059] The base part 62 forms an end portion of the displacement amplifying unit 42-1 opposite the base part 61 and is formed into a substantially rectangular shape The base part 62 is arranged on the side of an end portion of the piezoelectric element 41-1 where the piezoelectric element 41-1 as the driving member is displaced. The base part 62 receives force resulting from the displacement of the driving member. In other words, the base part 62 forms a part of the displacement amplifying unit 42-1 opposite the part thereof close to the finger 21-1. In this way, the base parts 61 and 62 are arranged in positions opposite each other in a direction where the piezoelectric element 41-1 expands and contracts while the piezoelectric element 41-1 is placed between the base parts 61 and 62.

[0060] A side surface of the base part 61 opposite the base part 62 is connected to one end of the second fulcrum beam 68 on its right side, and to one end of the first fulcrum beam 66 on its left side with intervention of the first fulcrum coupling part 67. This side surface is provided with the driving element fixing end 63 formed between the second fulcrum beam 68 and the first fulcrum coupling part 67 with intervention of the first point of effort coupling part 65. The first fulcrum coupling part 67 may be provided between the first fulcrum beam 66 and the base part 62.

[0061] A side surface of the base part 62 opposite the base part 61 is connected to one end of the second point of effort coupling part 70 on its right side and is connected to an opposite end of the first fulcrum beam 66 on its left side. The driving element fixing end 64 is formed between the second point of effort coupling part 70 and the first fulcrum beam 66.

[0062] In this way, the driving element fixing ends 63 and 64 are provided to the base parts 61 and 62 respectively so as be opposite each other. The driving element fixing end 63 is fixed to one end portion of the piezoelectric element 41-1.. The driving element fixing end 64 is fixed to an opposite end portion of the piezoelectric element 41-1. The piezoelectric element 41-1 expands and contracts in the Y-axis direction in response to application of a voltage. The expansion and contraction of the piezoelectric element 41-1 changes a gap between the driving element fixing ends 63 and 64. Figs. 7 to 11 show a condition where the piezoelectric element 41-1 expands in the Y-axis direction to move the finger 21-1 to the front side.

[0063] The first fulcrum beam 66 is formed into a bar extending on the left side of the piezoelectric element 41-1 in the Y-axis direction, specifically a bar connecting the base parts 61 and 62 in a direction parallel to the direction where the piezoelectric element 41-1 expands and contracts. The first fulcrum beam 66 is an example of a first beam. The first fulcrum beam 66 has one end connected to the base part 62 as a first receiving part and extends along one side surface of the driving member in the uniaxial direction where the driving member outputs displacement.

[0064] The second fulcrum beam 68 is formed into a bar extending on the right side of the piezoelectric element 41-1 in the Y-axis direction, specifically a bar extending from the base part 61 toward the base part 62 in a direction parallel to the direction where the piezoelectric element 41-1 expands and contracts. The second fulcrum beam 68 is an example of a second beam. The second fulcrum beam 68 has one end connected to the base part 61 as a second receiving part and extends along an opposite side surface of the driving member in the uniaxial direction where the driving member outputs displacement..

[0065] One end of the second fulcrum coupling part 69 is connected to an opposite end of the second fulcrum beam 68. An opposite end of the second fulcrum coupling part 69 is connected to one end of the displacement beam 71. An opposite end of the second point of effort coupling part 70 is connected to a right side surface of the displacement beam 71 in a position separated by about a quarter of the length of the displacement beam 71 from an end portion of the right side surface where the second fulcrum coupling part 69 is connected.

[0066] The displacement beam 71 is formed into a bar extending on the right side of the displacement amplifying unit 41-1 in the substantially Y-axis direction toward the latching unit 45-1. An opposite end of the displacement beam 71 is connected to one end of the displacement end position adjusting part 72. The displacement beam 71 is an example of a third beam. The displacement beam 71 extends in the uniaxial direction where the driving member outputs displacement along a side surface of the second fulcrum beam 68 as the second beam opposite a side surface thereof close to the driving member (piezoelectric element 41-1).

[0067] The displacement end position adjusting part 72 is formed into a bar extending in the X-axis direction to a position in the X-axis direction corresponding to the position of the pin 46. An opposite end of the displacement end position adjusting part 72 is connected to the displacement end 73. The displacement end 73 is formed into a bar extending in the Y-axis direction An end portion of the displacement end 73 close to the latching unit 45-1 has a shape like a sector with a central angle of 180 degrees or more as viewed from above.. The end portion of the displacement end 73 close to the latching unit 45-1 is coupled to the subject end 81.

[0068] The first point of effort coupling part 65, the first fulcrum coupling part 6 7, the second fulcrum coupling part 69, and the second point of effort coupling part 70 are each formed into a thin plate of a small width (small in the thickness in the X-axis direction). The first point of effort coupling part 65, the first fulcrum coupling part 67, the second fulcrum coupling part 69, and the second point of effort coupling part 70 are formed so as to be elastically deformed (deflected) in a certain direction in the horizontal plane 1 in response to application of force to the displacement amplifying unit 42-1 acting in the horizontal plane 1 in the certain direction resulting from the expansion and contraction of the piezoelectric element 41-1.

[0069] The first fulcrum coupling part 67 is an example of a first coupling part.. The first fulcrum coupling part 67 couples the opposite end of the first fulcrum beam 66 as the first beam and the base part 61 as the second receiving part. The first fulcrum coupling part 67 is elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the piezoelectric element 41-1 as the driving member. The second fulcrum coupling part 69 is an example of a second coupling part. The second fulcrum coupling part 69 couples one end of the displacement beam 71 as the third beam and the opposite end of the second fulcrum beam 68 as the second beam. The second fulcrum coupling part 69 is elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the piezoelectric element. 41-1 as the driving member. The second point of effort coupling part 70 is an example of a third coupling part. The second point of effort coupling part 70 couples a position at the side surface of the displacement beam 71 as the third beam separated by a given length from one end of the displacement beam 71 and the base part 62 as the first receiving part. The second point of effort coupling part 70 is elastically deformed as a point of effort in response to transmission of force resulting from the displacement of the piezoelectric element 41-1 as the driving member.

[0070] The first and second fulcrum beams 66 and 68, the displacement beam 71, the displacement end position adjusting part 72, and the displacement end 73 are formed to be greater in width than the first point of effort coupling part 65, the first fulcrum coupling part 67, the second fulcrum coupling part 69, and the second point of effort coupling part 70. The first and second fulcrum beams 66 and 68, the displacement beam 71, the displacement end position adjusting part 72, and the displacement end 73 are formed to have given rigidity so as not to be deformed easily in response to application of force to the displacement amplifying unit 42-1 resulting from the expansion and contraction of the piezoelectric element 41-1. The width of each of the first and second fulcrum beams 66 and 68, the displacement beam 71, the displacement end position adjusting part 72, and the displacement end 73 is reduced within a range in which the given rigidity is achieved to make deformation unlikely. This can reduce the width of the displacement amplifying unit 42-1 further.

[0071] The side surface of the base part 62 opposite the base part 61 may be connected to one end of the second fulcrum coupling part 69 on its right side and one end of the second point of effort coupling part 70 may be connected to the opposite end of the second fulcrum beam 68. In this case, the opposite end of the second point of effort coupling part 70 is connected to a left side surface of the displacement beam 71 in a position separated by about a quarter of the length of the displacement beam 71 from an end portion of the left side surface where the second fulcrum coupling part 69 is connected

[0072] The structure of the latching unit 45-1 is described next.

[0073] The subject end 81 is formed at an end portion of the latching unit 45-1 like a bar close to the displacement amplifying unit 42-1. The subject end 81 is formed into a recess of a semi-oval shape so as to receive therein the end portion like a sector of the displacement end 73 close to the latching unit 45-1. The end portion of the displacement end 73 close to the latching unit 45-1 is fitted in the recess of the subject end 81.

[0074] The hinge part 82 is separated from the subject end 81 by about one-fifth of the length of the latching unit 45-1. The hinge part 82 is fixed to the base 32 with the pin 46 passing through the hinge part 82 in a manner that allows the hinge part 82 to rotate freely.. The beam 83 is formed into a bar extending in the substantially Y-axis direction from the pin 46 toward the finger 21-1. The beam 83 is formed to a width that achieves given rigidity so as not to be deformed easily. The displacement end 84 is formed at an end portion of the latching unit 45-1 like a bar close to the finger 21-1. The displacement. end 84 has a semicircular tip as viewed from above the displacement end 84. The displacement end 84 is formed to contact the cam-like part 92 of the finger 21-1 in response to displacement to the left side..

[0075] The structure of the finger 21-1 is described next.

[0076] The abutting part 91 is an example of an action part to act on the working needle or the jack. The abutting part 91 is formed in a smooth plane. As an example, the abutting part 91 is formed in a vertical plane (plane parallel to the Z-axis direction) when pressing the approaching working needle or jack. As an example, the abutting part 91 is formed in an obliquely upward plane (upward plane crossing the Z-axis direction) when lifting the approaching working needle or jack. When the finger 21-1 rotates clockwise about the pin 47 to move toward the rear side, the abutting part 91 becomes substantially flush with the front surface of the base 32. When the finger 21-1 rotates anticlockwise about the pin 47 to move to the front side, the abutting part 91 projects from the front surface of the base 32 at a given angle relative to the pin 47 The cam-like part 92 is an example of a subject part to receive driving force The cam-like part 92 is formed close to the displacement end 84 of the latching unit 45-1 to be opposite the abutting part 91. The cam-like part 92 is formed into a curved surface responsive to the rotation angle of the finger 21-1. The cam-like part 92 is formed as a cam as a mechanical element to change the direction of motion. The cam-like part 92 is what is called a plate cam (circumference cam). Alternatively, the cam-like part 92 may be a planar cam such as a grooved cam or a solid cam.

[0077] The angle regulating part 93 is formed on the left side of the finger 21-1 into a projection of a shape responsive to a side surface of the pin 48. The projection 94 is a projecting part formed in a position opposite the cam-like part 92 while the recess 95 is placed between the projection 94 and the cam-like part 92. The projection 94 is formed to project to the left rear side from the pin 47. The projection 94 is formed into a length that avoids contact of the projection 94 with the displacement end 84 when the displacement end 84 moves to the left side and makes the projection 94 abut on the right side surface of the displacement end 84 when the displacement end 84 moves to the right side..

[0078] The recess 95 is formed between the cam-like part 92 and the projection 94. The recess 95 is formed as a substantially U-shaped recess responsive to the shape of the tip of the displacement end 84 to allow the tip of the displacement end 84 to fit in the recess 95.

[0079] The following describes how the finger 21-1 and the driving unit 31-1 behave while the finger 21-1 is to be moved to the front side.

[0080] In this case, a voltage is applied first to the piezoelectric element 41-1 in a direction that makes the piezoelectric element 41-1 expand The piezoelectric element 41-1 expands in the Y-axis direction in response to application of this voltage. The piezoelectric element 41-1 is held between the driving element fixing ends 63 and 64 of the displacement amplifying unit 42-1.. Thus, a gap between the driving element fixing ends 63 and 64 is increased to increase a gap between the base parts 61 and 62 determined in positions in the X-axis direction where the driving element fixing ends 63 and 64 are arranged. Meanwhile, the respective left sides of the base parts 61 and 62 are connected through the first fulcrum beam 66 and the first fulcrum coupling part 67.. Thus, a gap between the respective left sides of the base parts 61 and 62 is not changed.

[0081] The expansion of the piezoelectric element 41-1 displaces the positions of the base parts 61 and 62 relative to each other such that the respective right sides of the base parts 61 and 62 are separated further. The base part 61 is fixed to the base 32 in a manner that does not allow the displacement of the base part 61, so that the base part 62 is displaced so as to rotate anticlockwise as viewed from above.

[0082] The first point of effort coupling part 65 and the first fulcrum coupling part 67 are each formed into a thin plate of a small width for allowing elastic deformation. Thus, these displacements of the base parts 61 and 62 in a manner that separates the respective right sides of the base parts 61 and 62 further maintain the respective positions of the piezoelectric element 41-1 and the first fulcrum beam 66 relative to the base part 62 and bend (elastically deform) the first point of effort coupling part 65 and the first fulcrum coupling part 67. This changes the respective angular positions of the piezoelectric element 41-1 and the first fulcrum beam 66 relative to the base part 61. In other words, the base parts 61 and 62, and the first and second fulcrum beams 66 and 68 behave as a lever while the first fulcrum coupling part 67 functions as a fulcrum and the first point of effort coupling part 65 functions as a point of effort.

[0083] More specifically, the lever is formed of the base parts 61 and 62, the driving element fixing end 63, the driving element fixing end 64, the first point of effort coupling part 65, the first fulcrum beam 66, the first fulcrum coupling part 67, and the second fulcrum beam 68 while the first fulcrum coupling part 67 functions as the fulcrum and the first point of effort coupling part 65 functions as the point of effort of this lever. This lever changes displacement resulting from the expansion of the piezoelectric element 41-1 to the displacement of a gap between the base part 62 and the second fulcrum beam 68. With the fulcrum placed on the left side of the displacement amplifying unit 42-1, with the point of effort at the substantially central portion of the X-axis direction of the displacement amplifying unit 42-1, and with what is called a point of load on the right side of the displacement amplifying unit 42-1, the displacement of the gap between the base part 62 and the second fulcrum beam 68 is amplified in comparison to the displacement of the piezoelectric element 41-1.

[0084] The length of the base part 61 in the X-coordinate direction is defined as X1, a length from the first fulcrum coupling part 67 to the first point of effort coupling part 65 is defined as X2, and an increase in the gap between the driving element fixing ends 63 and 64 resulting from the expansion of the piezoelectric element 41-1 is defined as ΔY. Then, the respective right sides of the base parts 61 and 62 are separated further by X1/X2 × ΔY approximately. More specifically, the respective right sides of the base parts 61 and 62 are separated further by about 2 × ΔY.

[0085] The first point of effort coupling part 65 and the first fulcrum coupling part 67 are bent. This maintains the position of the piezoelectric element 41-1 relative to the base part 62 and maintains the position of the driving element fixing end 63 relative to the piezoelectric element 41-1. As a result, the piezoelectric element 41-1 can be prevented from being deformed due to its twist This can prevent shortening of the lifetime of the piezoelectric element 41-1 due to its distortion.

[0086] While the respective right sides of the base parts 61 and 62 are separated further in the Y-axis direction, the position of one end (end portion on the rear side) of the displacement beam 71 is maintained substantially unchanged by the second fulcrum beam 68 and the second fulcrum coupling part 69. Meanwhile, if the respective right sides of the base parts 61 and 62 are separated further in the Y-axis direction, the second point of effort coupling part 70 connected to the right side of the base part 62 pulls the displacement beam 71 to the right side in a position where the opposite end of the second point of effort coupling part 70 is connected.. At this time, the second fulcrum coupling part 69 and the second point of effort coupling part 70 are bent (elastically deformed) to change the angular position of the displacement beam 71 relative to the base part 62 Specifically, the displacement beam 71 behaves as a lever while the second fulcrum coupling part 69 functions as a fulcrum and the second point of effort coupling part 70 functions as a point of effort.

[0087] More specifically, the second fulcrum coupling part 69, the second point of effort coupling part 70, the displacement beam 71, the displacement end position adjusting part 72, and the displacement end 73 form a lever while the second fulcrum coupling part 69 functions as the fulcrum and the second point of effort coupling part 70 functions as the point of effort of this lever. This lever changes the displacement of the gap between the base part 62 and the second fulcrum beam 68 in the Y-axis direction to the displacement of the displacement end 73 in the X-axis direction. With the fulcrum placed on an end portion of the displacement beam 71 (one end thereof close to the base part 62), with the point of effort in the middle of the displacement beam 71, and with what is called a point of load on the displacement end 73, the displacement of the displacement end 73 is amplified in comparison to the displacement of the gap between the base part 62 and the second fulcrum beam 68.

[0088] The opposite end of the second point of effort coupling part 70 is placed in the middle of the right side of the displacement beam 71 and is connected to the position separated by about a quarter of the length of the displacement beam 71 from the end portion of the displacement beam 71 where the second fulcrum coupling part 69 is connected Thus, according to the principle of leverage, the opposite end of the displacement beam 71 is displaced in the X-axis direction by a length four times longer than a length corresponding to the further separation between the respective right sides of the base parts 61 and 62. Additionally, the length of the displacement end 73 corresponds to about a quarter of the length of the displacement beam 71. Thus, a length from one end (end portion on the rear side) of the displacement beam 71 to a tip of the displacement end 73 is five times longer than a length from one end of the displacement beam 71 to the position where the opposite end of the second point of effort coupling part 70 is connected.

[0089] As a result, an opposite end of the displacement end 73 is displaced to the right side (X-axis direction) by a length about 5 × 2 × ΔY = 10 × ΔY, specifically a length 10 times longer than the length of the expansion of the piezoelectric element 41-1.

[0090] Displacing the displacement end 73 to the right side displaces the subject end 81 to the right side by the same length as the displacement of the displacement end 73. A length from the hinge part 82 to the subject end 81 is about one-fifth of a length from the hinge part 82 to the displacement end 84 Thus, the displacement end 84 is displaced to the left side (X-axis direction) by a length five times longer than the length of the displacement of the subject end 81 to the right side (X-axis direction).

[0091] The displacement end 84 is eventually displaced to the left side (X-axis direction) by a length about 5 × 5 × 2 × ΔY = 50 × ΔY, specifically a length 50 times longer than the length of the expansion of the piezoelectric element 41-1.

[0092] Moving the displacement end 84 to the left side makes the displacement end 84 press the projecting portion of the cam-like part 92, thereby moving the finger 21-1 to the front side More specifically, when the displacement end 84 presses the cam-like part 92, the finger 21-1 rotates anticlockwise about the pin 47 to move to the front side. At this time, the abutting part 91 moves to a position where the abutting part 91 abuts on the working needle or the jack.

[0093] The angle regulating part 93 is formed into a projection. Thus, when the finger 21-1 moves to the front side, the angle regulating part 93 abuts on the pin 48 to regulate the angular position of the finger 21-1 such that the finger 21-1 is placed in a given angular position relative to the base 32.

[0094] In this way, the finger 21-1 moves to the front side and the abutting part 91 of the finger 21-1 moves to a position where the abutting part 91 abuts on the working needle or the jack. As a result of the movement of the finger 21-1 to the front side, the abutting part 91 abuts on the approaching working needle or jack and then presses or lifts the working needle or the jack.

[0095] While the displacement end 84 has moved to the left side and presses the projecting portion of the cam-like part 92 and the finger 21-1 has moved to the front side, the abutting part 91 and the cam-like part 92 of the finger 21-1 and the displacement end 84, the beam 83 and the hinge part 82 of the latching unit 45-1 are arranged in a substantially linear pattern in the Y-axis direction. As a result of abutting contact of the approaching working needle or jack with the abutting part 91, force applied to the finger 21-1 acts backward, specifically in a substantially linear pattern in the Y-axis direction. Thus, application of force to the finger 21-1 still maintains the positions of the finger 21-1 and the latching unit 45-1 relative to each other and the latching unit. 45-1 receives the force applied to the finger 21-1 for displacement of the working needle.. Specifically, the latching unit 45-1 receives the force applied to the finger 21-1 for displacement of the working needle to maintain the position of the finger 21-1. Eventually, the force applied to the finger 21-1 is received by the hinge part 82 and the pin 46 and is not transmitted to the displacement amplifying unit 42-1.

[0096] As described above, if the abutting part 91 of the finger 21-1 is to act to displace the working needle, the latching unit 45-1 holds the finger 21-1 such that the abutting part 91 is in a position where the abutting part 91 acts on the working needle or the jack and receives force applied to the finger 21-1 for displacement of the working needle.

[0097] The following describes how the finger 21-1 and the driving unit 31-1 behave while the finger 21-1 is to be moved to the rear side. For moving the finger 21-1 to the rear side, the finger 21-1 and the driving unit 31-1 behave in the opposite direction but basically in the same manner as the behaviors of the finger 21-1 and the driving unit 31-1 for moving the finger 21-1 to the front side

[0098] In this case, after the force applied to the displacement amplifying unit 42-1 is removed, a voltage is applied to the piezoelectric element 41-1 in a direction that makes the piezoelectric element 41-1 contract or application of a voltage in a direction that makes the piezoelectric element 41-1 expand is stopped in a condition where the displacement end 84 is placed on the left side and the piezoelectric element 41-1 expands.

[0099] As a result, the piezoelectric element 41-1 contracts in the Y-axis direction. This reduces the gap between the driving element fixing ends 63 and 64 to reduce the gap between the base parts 61 and 62 determined in positions in the X-axis direction where the driving element fixing ends 63 and 64 are arranged. Meanwhile, the respective left sides of the base parts 61 and 62 are connected through the first fulcrum beam 66 and the first fulcrum coupling part 67. Thus, the gap between the respective left sides of the base parts 61 and 62 is not changed.

[0100] The contraction of the piezoelectric element 41-1 displaces the positions of the base parts 61 and 62 relative to each other such that the respective right sides of the base parts 61 and 62 get closer. The base part 61 is fixed to the base 32 in a manner that does not allow the displacement of the base part 61, so that the base part 62 is displaced so as to rotate clockwise as viewed from above. In this case, the base parts 61 and 62, and the first and second fulcrum beams 66 and 68 also behave as a lever while the first fulcrum coupling part 67 functions as a fulcrum and the first point of effort coupling part 65 functions as a point of effort.

[0101] If the respective right sides of the base parts 61 and 62 get closer in the Y-axis direction, the second point of effort coupling part 70 connected to the right side of the base part 62 pushes the displacement beam 71 to the left side in the position where the opposite end of the second point of effort coupling part 70 is connected. At this time, the second fulcrum coupling part 69 and the second point of effort coupling part 70 are bent (elastically deformed) to change the angular position of the displacement beam 71 relative to the base part 62. Specifically, the displacement beam 71 behaves as a lever while the second fulcrum coupling part 69 functions as a fulcrum and the second point of effort coupling part 70 functions as a point of effort.

[0102] While the finger 21-1 is to be moved to the rear side, the opposite end of the displacement end 73 is displaced to the left side (X-axis direction) by a length 10 times longer than the length of the contraction of the piezoelectric element 41-1, like in the case of moving the finger 21-1 to the front side.

[0103] Displacing the displacement end 73 to the left side displaces the subject end 81 to the left side by the same length as the displacement of the displacement end 73. In this case, the displacement end 84 is displaced to the right side (X-axis direction) also by a length five times longer than the length of the displacement of the subject end 81 to the left side (X-axis direction).

[0104] The displacement end 84 is eventually displaced to the right side (X-axis direction) by a length about 50 times longer than the length of the contraction of the piezoelectric element 41-1.

[0105] Moving the displacement end 84 to the right side makes the right side surface of the displacement end 84 press the projection 94, thereby moving the finger 21-1 to the rear side. More specifically, when the right side surface of the displacement end 84 presses the projection 94, the finger 21-1 rotates clockwise about the pin 47 to move to the rear side. At this time, the abutting part 91 moves to a position where the abutting part 91 does not abut on the working needle or the jack.

[0106] The recess 95 is formed as a substantially U-shaped recess responsive to the shape of the tip of the displacement end 84 to allow the tip of the displacement end 84 to fit in the recess 95. Thus, when the displacement end 84 moves to the right side to move the finger 21-1 to the rear side, the tip of the displacement end 84 fits into the recess 95.. This allows the finger 21-1 to move to the rear side without interfering with the displacement end 84.

[0107] In this way, the finger 21-1 moves to the rear side and the abutting part 91 of the finger 21-1 moves to a position where the abutting part 91 does not abut on the working needle or the jack. As a result of the movement of the finger 21-1 to the rear side, the abutting part 91 does not abut on the approaching working needle or jack but it lets the working needle or the jack pass therethrough.

[0108] The projection 94 may be omitted. In this case, the movement of the displacement end 84 to the right side does not move the finger 21-1 to the rear side but it keeps the finger 21-1 in its position on the front side. If the abutting part 91 of the finger 21-1 abuts on the approaching working needle or jack in this condition, the finger 21-1 moves to the rear side in response to application of force from the working needle or the jack.

[0109] The cam-like part 92 may have a tiny projection at a boundary with the recess 95 projecting toward the rear side. In this case, if the apex of the displacement end 84 at the tip moves to the left of this projection, force applied to the finger 21-1 for displacement of the working needle moves the displacement end 84 further to the left side. This allows the latching unit 45-1 to more reliably hold the finger 21-1 in a position where the abutting part 91 acts on the working needle or the jack and to receive force applied to the finger 21-1 for displacement of the working needle.

[0110] Meanwhile, if the apex of the displacement end 84 at the tip moves to the right of the aforementioned projection, force applied to the finger 21-1 for displacement of the working needle moves the displacement end 84 further to the right side. This allows the tip of the displacement end 84 to more reliably fit into the recess 95 to move the finger 21-1 to the rear side, thereby moving the abutting part 91 of the finger 21-1 to a position where the abutting part 91 does not abut on the working needle or the jack.

[0111] As described above, even if the displacement of the displacement end 84 is reduced for some reason, the movement of the tip of the displacement end 84 to the left or right of the projection provided to the cam-like part 92 still allows press or lift of the working needle or the jack, or can let the working needle or the jack pass through.

[0112] As described above, the position of the displacement end 84 of the latching unit 45-1 forming the driving unit 31-1 is displaced in the horizontal plane 1 in response to the expansion and contraction of the piezoelectric element 41-1. The latching unit 45-1 rotates clockwise or anticlockwise about the hinge part 82 hinging on the pin 46, so that the displacement end 84 is displaced at least between two positions on an arc in the horizontal plane 1. Specifically, the driving unit 31-1 generates driving force to cause displacement at least between the two positions on the arc in the horizontal plane 1. The latching unit 45-1 is arranged to extend in the Y-axis direction, making the chord of the arc where the displacement end 84 is placed extend like a straight line in the X-axis direction.

[0113] The position of the abutting part 91 of the finger 21-1 is displaced in the horizontal plane 1 in response to the expansion and contraction of the piezoelectric element 41-1. The finger 21-1 rotates clockwise or anticlockwise about the pin 47, so that the abutting part 91 is displaced at least between two positions on an arc in the horizontal plane 1 Specifically, the abutting part 91 of the finger 21-1 is displaced at least between the two positions on the arc in the horizontal plane 1. The finger 21-1 moves to the front side or to the rear side defined in the Y-axis direction, making the chord of the arc where the abutting part 91 of the finger 21-1 is placed extend like a straight line in the substantially Y-axis direction.

[0114] Specifically, the abutting part 91 of the finger 21-1 is displaced at least between the two positions on the arc having a chord as a straight line extending substantially along the Y axis in a direction crossing the direction of the chord (straight line in the X-axis direction) of the arc on which the displacement end 84 is placed.

[0115] As described above, the driving unit 31-1 generates driving force to cause displacement between two first positions on a first arc in the horizontal plane 1. The finger 21-1 includes the cam-like part 92 as a subject part to receive the driving force, and the abutting part 91 as an action part to act on the working needle or the jack. The abutting part 91 is formed to be opposite the cam-like part 92. The cam-like part 92 is formed into a cam. In response to application of driving force to the cam-like part 92 resulting from displacement to one of the first positions, the abutting part 91 is displaced to one of two second positions on a second arc in the horizontal plane 1 having a chord extending in a direction crossing the direction of the chord of the first arc.

[0116] The finger 21-1 is displaced in the horizontal plane 1 so as to displace the abutting part 91 to one of the two second positions on the second arc in the horizontal plane 1. This can narrow the pitch further compared to the case where a finger is moved up and down. The driving part. 31-1 and the finger 21-1 behave so as to be displaced on the respective arcs. Thus, in terms of the length of the displacement of the displacement end 84 or the abutting part 91 and the moving distance of the center of gravity of the displacement end 84 or the abutting part 91 being displaced, the moving distance of the center of gravity can be shortened further compared to the case where the displacement end 84 or the abutting part 91 is displaced in a straight line. This allows behavior at a higher speed. Thus, the moving speed (rotation speed) of the working needle or the jack of the knitting machine can be maintained and even increased.

[0117] The driving unit 31-1 generates driving force to cause displacement between the two first positions on the first arc in the horizontal plane 1. The finger 21-1 is displaced in the horizontal plane 1 so as to displace the abutting part 91 to one of the two second positions on the second arc in the horizontal plane 1. Thus, the driving unit 31-1 and the finger 21-1 can be made thinner in the Z-axis direction.

[0118] If fingers are to be moved up and down, the positions of the fingers relative to each other should be managed determined when one of the fingers is moved up while a finger above this finger is moved down. In comparison to this case, displacing the finger 21-1 in the horizontal plane 1 allows the accuracy of assembly of the needle selector 11 to be managed in a wider range.

[0119] The horizontal plane 1 can be a plane perpendicular to a direction where the working needle to be selected moves. In this case, a range of action of the abutting part 91 on the working needle or the jack is perpendicular to the horizontal plane 1.. This facilitates installation of the needle selector 11 on the knitting machine further. This also allows accuracy relating to the knitting machine to be managed in a wider range.

[0120] In response to the expansion and contraction of the piezoelectric element 41-1, the position of the displacement end 73 of the displacement amplifying unit 42-1 is displaced in the horizontal plane 1. The displacement beam 71, the displacement end position adjusting part 72, and the displacement end 73 rotate clockwise or anticlockwise about the end portion of the displacement beam 71 supported on the second fulcrum coupling part 69. Thus, the position of the displacement end 73 of the displacement amplifying unit 42-1 is displaced at least between two positions on an arc in the horizontal plane 1. Specifically, the displacement amplifying unit 42-1 generates driving force to cause displacement at least between the two positions on the arc in the horizontal plane 1. The displacement amplifying unit 42-1 is arranged such that the displacement beam 71, the displacement end position adjusting part 72, and the displacement end 73 extend in the Y-axis direction, making the chord of the arc where the displacement end 73 is placed extend like a straight line in the X-axis direction

[0121] The displacement end 73 may directly press the projecting portion of the cam-like part 92. In this case, a pin provided on the rear side of a connection between the displacement end 73 pressing the projecting portion of the cam-like part 92 and the displacement end position adjusting part 72 may receive force applied to the finger 21-1.

[0122] The driving unit 31-1 can include the latching unit 45-1 that holds the finger 21-1 such that the abutting part 91 is in a position on the front side where the abutting part 91 acts on the working needle or the jack and receives force applied to the finger 21-1 for displacement of the working needle if the abutting part 91 of the finger 21-1 is to act to displace the working needle. Even if the driving unit 31-1 cannot generate force to hold the finger 21-1 in position, specifically force against force applied to the finger 21-1 for displacement of the working needle, this can displace the working needle reliably. This can further avoid unnecessary transmission of force, thereby enhancing durability.

[0123] The driving unit 31-1 can further include the displacement amplifying unit 42-1 that amplifies displacement generated by a driving element such as the piezoelectric element 41-1 and generates driving force for displacement between the first positions on the first arc in a plane. This allows application of the piezoelectric element 41-1 to be deformed in the D33 mode that has not been allowed to be used in a needle selector for a knitting machine. The piezoelectric element 41-1 to be deformed in the D33 mode can be deformed at a higher speed, thereby allowing the needle selector 11 to behave at a higher speed.

[0124] As described above, the driving unit 31-1 as an actuator of a needle selector for a knitting machine can include the piezoelectric element 41-1 as a driving member that outputs displacement in the uniaxial direction responsive to the quantity of input energy, and the displacement amplifying unit 42-1 as a displacement amplifying mechanism that amplifies the displacement output from the driving member. The displacement amplifying unit 42-1 includes: the base part 62 as the first receiving part arranged on the side of one end portion of the driving member where the driving member is displaced and receiving force resulting from the displacement of the driving member; the base part 61 as the second receiving part arranged on the side of an opposite end portion of the driving member where the driving member is displaced, fixed to the needle selector 31-1, and receiving force resulting from the displacement of the driving member; the first fulcrum beam 66 as the first beam having one end connected to the first receiving part and extending in the uniaxial direction along one side surface of the driving member; the second fulcrum beam 68 as the second beam having one end connected to the second receiving part and extending in the uniaxial direction along an opposite side surface of the driving member; the first fulcrum coupling part 67 as the first coupling part coupling the opposite end of the first beam and the second receiving part and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; the displacement beam 71 as the third beam extending in the uniaxial direction along a side surface of the second beam opposite a side surface of the second beam close to the driving member; the second fulcrum coupling part 69 as the second coupling part coupling one end of the third beam and the opposite end of the second beam and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; and the second point of effort coupling part 70 as the third coupling part coupling a position of the side surface of the third beam separated by a given length from one end of the third beam and the first receiving part and being elastically deformed as a point of effort in response to transmission of force resulting from the displacement of the driving member. The displacement amplifying unit 42-1 outputs amplified displacement from an opposite end of the third beam. The first, second, and third beams extend in the uniaxial direction This can reduce a width further indicating a length in a direction crossing the uniaxial direction. Further, the piezoelectric element 41-1 to be deformed in the D33 mode that has not been allowed to be used in a needle selector for a knitting machine can be applied as a driving member. The piezoelectric element 41-1 to be deformed in the D33 mode can be deformed at a higher speed, thereby allowing the needle selector 11 to behave at a higher speed.

[0125] Each of the displacement amplifying units 42-2 to 42-4 is configured and behaves in the same manner as the displacement amplifying unit 42-1. Each of the latching units 45-2 to 45-4 is configured and behaves in the same manner as the latching unit 45-1. Each of the fingers 21-2 to 21-4 is configured and behaves in the same manner as the finger 21-1. Specifically, each of the driving units 31-2 to 31-4 is configured and behaves in the same manner as the driving unit 31-1.

[0126] In the foregoing description, the piezoelectric elements 41-1 to 41-4 are provided as a driving member (driving element). However, the driving member (driving element) is not limited to the piezoelectric elements 41-1 to 41-4 but it may also be a magnetostrictive element to be deformed in response to application of a magnetic field from outside, a solenoid actuator with a solenoid having a movable core or a magnet piece therein to move the movable core or the magnet piece with a current, or a shape-memory alloy. As an example, the magnetostrictive element can be deformed with a current flowing in a coil wound around the magnetostrictive element. As another example, the shape-memory alloy to be deformed according to a temperature can be deformed by changing the temperature with Joule heat resulting from a current flowing in the shape-memory alloy.

[0127] A needle selector described below according to an embodiment of this invention employs a bimorph piezoelectric element as a driving element.

[0128] Figs. 14 to 19 show an exemplary appearance of a needle selector 101 according to an embodiment of this invention.

[0129] Fig. 14 is a perspective view showing the exemplary appearance of the needle selector 101. Figs. 15, 16, 17, 18, and 19 are a top view, a front view, a right side view, a bottom view, and a back view respectively showing the exemplary appearance of the needle selector 101. A left side view showing the exemplary appearance of the needle selector 101 is to include a shape symmetric to the shape of the right side view of Fig. 17, so that this left side view will not be shown.

[0130] In the drawings, a lengthwise direction referred to below with respect to the needle selector 101 is indicated by a Y axis, a vertical direction is indicated by a Z axis, and a lateral direction is indicated by an X axis. In the below, the left side of the X-axis direction of Fig. 16 is simply called a left side whereas the right side of the X-axis direction of Fig. 16 is simply called a right side. In the below, the front side of the Y-axis direction of Fig.. 16 is simply called a front side whereas the rear side of the Y-axis direction of Fig. 16 is simply called a rear side. In the below, the upper side of the Z-axis direction of Fig. 16 is simply called an upper side whereas the lower side of the Z-axis direction of Fig. 16 is simply called a lower side.

[0131] The needle selector 101 is attached to a knitting machine such as a weft knitting machine or a warp knitting machine that is for example a horizontal knitting machine or a hosiery knitting machine. In the below, the needle selector 101 is to be attached for example to a circular knitting machine. The needle selector 101 makes a working needle behave in a manner responsive to a pattern. To achieve this, the needle selector 101 selects the behavior of the working needle. Covers are provided to the upper surface, the front, the right side surface, and the left side surface of the needle selector 101. The bottom surface of the needle selector 101 is provided with a groove to be used for positioning at the knitting machine when the needle selector 101 is attached to the knitting machine. The back surface of the needle selector 101 is provided with a terminal for electrical connection.

[0132] The needle selector 101 is provided with fingers 121-1 to 121-4 The fingers 121-1 to 121-4 select the behavior of the working needle according to positions where the fingers 121-1 to 121-4 are displaced.

[0133] The fingers 121-1 to 121-4 are each made of a metallic material integrally. Each of the fingers 121-1 to 121-4 can be made of resin such as engineering plastic or a composite material such as fiber-reinforced plastic. Each of the fingers 121-1 to 121-4 can be molded by pressing, cutting, casting, injection molding or metallic powder injection molding, or a combination of these processes

[0134] The fingers 121-1 to 121-4 are each displaced so as to project through a hole in the cover on the front of the needle selector 101 or go inside the cover on the front of the needle selector 101. Specifically, the fingers 121-1 to 121-4 each move to the front or rear side. When moving to the front side, the fingers 121-1 to 121-4 press or lift the approaching working needle or a jack. When moving to the rear side, the fingers 121-1 to 121-4 let the working needle or the jack pass therethrough.

[0135] The fingers 121-1 to 121-4 have the same shape as the finger 21-1. The finger 121-1 is arranged at the bottom. The fingers 121-2, 121-3, and 121-4 are arranged in this order above the finger 121-1. The fingers 121-1 to 121-4 are arranged so as to overlap in the Z-axis direction. The fingers 121-1 to 121-4 are spaced by a constant pitch.

[0136] Fig. 20 is a perspective view showing an internal structure of the needle selector 101. Fig. 21 is a top view showing the internal structure of the needle selector 101. Fig. 22 is a right side view showing the internal structure of the needle selector 101. Driving units 131-1 to 131-4 are arranged inside the needle selector 101 on a base 132 arranged on the bottom surface of the needle selector 101. The driving units 131-1 to 131-4 drive the fingers 121-1 to 121-4 respectively. The base 132 functions as a foundation of the needle selector 101 to which the driving units 131-1 to 131-4 and the fingers 121-1 to 121-4 are fixed..

[0137] More specifically, the fingers 121-1 to 121-4, piezoelectric elements 141-1 to 141-4, latching units 142-1 to 142-4, a pin 143, a pin 144, a pin 145, a pin 146, and a pin 147 are provided inside the needle selector 101.

[0138] The driving unit 131-1 is formed of the piezoelectric element 141-1, the latching unit 142-1, and the pin 143. The driving unit 131-2 is formed of the piezoelectric element 141-2, the latching unit 142-2, and the pin 143. The driving unit 131-3 is formed of the piezoelectric element 141-3, the latching unit 142-3, and the pin 143. The driving unit 131-4 is formed of the piezoelectric element 141-4, the latching unit 142-4, and the pin 143

[0139] The piezoelectric elements 141-1 to 141-4 are what are called bimorph piezoelectric elements.. The piezoelectric elements 141-1 to 141-4 are each formed of a metallic plate and piezoelectric elements stacked on opposite sides of the metallic plate. The piezoelectric elements 141-1 to 141-4 are each formed into a substantially rectangular thin plate. The piezoelectric elements 141-1 to 141-4 have the same shape. The piezoelectric elements 141-1 to 141-4 each become electrically charged to be bent in response to application of a voltage from outside. Specifically, each of the piezoelectric elements 141-1 to 141-4 is bent such that its end portion of the longitudinal direction of the substantially rectangular shape is displaced in the thickness direction.

[0140] The piezoelectric elements 141-1 to 141-4 are each arranged such that its end portion of the longitudinal direction of the substantially rectangular shape is displaced in the X-axis direction. Specifically, the piezoelectric elements 141-1 to 141-4 are arranged such that a plane like a thin plate of each of the piezoelectric elements 141-1 to 141-4 is parallel to a vertical plane defined by the Y axis and the Z axis. The piezoelectric elements 141-1 to 141-4 are arranged in this order from the left at intervals that avoid interference with each other.

[0141] The piezoelectric element 141-1 is provided with a supporting part 151-1, a supporting part 152-1, and a transmitting part 153-1. The piezoelectric element 141-2 is provided with a supporting part 151-2, a supporting part 152-2, and a transmitting part 153-2 The piezoelectric element 141-3 is provided with a supporting part 151-3, a supporting part 152-3, and a transmitting part 153-3. The Piezoelectric element 141-4 is provided with a supporting part 151-4, a supporting part 152-4, and a transmitting part 153-4

[0142] The supporting parts 151-1 to 151-4 are formed so as to respectively grip the piezoelectric elements 141-1 to 141-4 formed into substantially rectangular thin plates at their end portions on the rear sides of their longitudinal directions. When assembled into the needle selector 101, the supporting parts 151-1 to 151-4 are supported by the needle selector 101 in a manner that allows the supporting parts 151-1 to 151-4 to rotate freely in the Z-axis direction.

[0143] The supporting parts 152-1 to 152-4 are formed so as to respectively cross the piezoelectric elements 141-1 to 141-4 in their short-side directions at substantially middle positions of the piezoelectric elements 141-1 to 141-4 formed into substantially rectangular thin plates. The supporting parts 152-1 to 152-4 are each formed to project from opposite sides of the longitudinal direction of a corresponding one of the piezoelectric elements 141-1 to 141-4. The supporting parts 152-1 to 152-4 grip the piezoelectric elements 141-1 to 141-4 respectively. When assembled into the needle selector 101, the Supporting parts 152-1 to 152-4 are supported by the needle selector 101 in a manner that allows the supporting parts 152-1 to 152-4 to rotate freely in the Z-axis direction.

[0144] The transmitting parts 153-1 to 153-4 are formed so as to respectively grip the piezoelectric elements 141-1 to 141-4 formed into substantially rectangular thin plates at their end portions on the front sides of their longitudinal directions. When assembled into the needle selector 101, the transmitting parts 153-1 to 153-4 are inserted in subject ends (described later) of the latching units 143-3 to 142-4 respectively. Thus, bending the piezoelectric elements 141-1 to 141-4 rotates the latching units 142-3 to 142-4 respectively.

[0145] The latching units 142-1 to 142-4 are each made of a metallic material integrally. Each of the latching units 142-1 to 142-4 can be made of resin such as engineering plastic or a composite material such as fiber-reinforced plastic. Each of the latching units 142-1 to 142-4 can be molded by pressing, cutting, casting, injection molding or metallic powder injection molding, or a combination of these processes.

[0146] The latching units 142-1 to 142-4 are formed into bars bent at respective angles. The latching units 142-1 to 142-4 are fixed to the base 132 with the pin 143 in a manner that allows the latching units 142-1 to 142-4 to rotate freely. If one end of each of the latching units 142-1 to 142-4 is displaced by a corresponding one of the piezoelectric elements 141-1 to 141-4, each of the latching units 142-1 to 142-4 rotates about the pin 143. Respective opposite ends of the latching units 142-1 to 142-4 rotating about the pin 143 press the fingers 121-1 to 121-4, thereby transmitting driving forces to the fingers 121-1 to 121-4 respectively.

[0147] The fingers 121-1 to 121-4 are fixed to the base 132 in a manner that allows the fingers 121-1 to 121-4 to rotate freely about the pin 144. The pin 145 makes abutting contacts with the fingers 121-1 to 121-4, thereby restricting the respective positions of the fingers 121-1 to 121-4 when the fingers 121-1 to 121-4 move to the front side.

[0148] The pin 146 makes abutting contacts with the latching units 142-1 to 142-4, thereby restricting the respective positions of the latching units 142-1 to 142-4 when the latching units 142-1 to 142-4 move to the right side. The pin 147 makes abutting contacts with the latching units 142-1 to 142-4, thereby restricting the respective positions of the latching units 142-1 to 142-4 when the latching units 142-1 to 142-4 move to the left side.

[0149] The structures of the fingers 121-1 to 121-4 and those of the latching units 142-1 to 142-4 are described in detail next by referring to Figs. 23 and 24.

[0150] Fig. 23 is an enlarged top view showing the structure of the finger 121-4 and that of the latching unit 142-4 in detail determined when the fingers 121-1 to 121-4 have moved to the front side. Fig. 24 is an enlarged top view showing the structure of the finger 121-4 and that of the latching unit 142-4 in detail determined when the fingers 121-1 to 121-4 have moved to the rear side.

[0151] The structure of the latching unit 142-4 is described next.

[0152] A subject end 181 is formed at an end portion of the latching unit 142-4 close to the piezoelectric element 141-4. The subject end 181 is formed into a recess of a semi-oval shape so as to receive therein the transmitting part 153-4. The transmitting part 153-4 is fitted in the recess of the subject end 181.

[0153] A hinge part 182 is separated from the subject end 181 in the Y-axis direction by about one-fifth of the length of the latching unit 142-4 in the Y-axis direction. The hinge part 182 is fixed to the base 132 with the pin 143 passing through the hinge part 182 in a manner that allows the hinge part 182 to rotate freely. A beam 183 is formed into a bar extending in the substantially Y-axis direction from the pin 143 toward the finger 121-4. The beam 183 is formed to have given rigidity so as not to be deformed easily. A displacement end 184 is formed at an end portion of the latching unit 142-4 like a bar bent at a given angle close to the finger 121-4. The displacement end 184 has a semicircular tip as viewed from above the displacement end 184. The displacement end 184 is formed to contact a cam-like part 192 of the finger 121-4 in response to displacement to the left side.

[0154] The structure of the finger 121-4 is described next.

[0155] An abutting part 191 is an example of an action part to act on the working needle or the jack. The abutting part 191 is formed in a smooth plane. As an example, the abutting part 191 is formed in a vertical plane (plane parallel to the Z-axis direction) when pressing the approaching working needle or jack. As an example, the abutting part 191 is formed in an obliquely upward plane (upward plane crossing the Z-axis direction) when lifting the approaching working needle or jack. When the finger 121-4 rotates clockwise about the pin 144 to move toward the rear side, the abutting part 191 becomes substantially flush with the front surface of the base 132. When the finger 121-4 rotates anticlockwise about the pin 144 to move to the front side, the abutting part 191 projects from the front surface of the base 132 at a given angle relative to the pin 144. The cam-like part 192 is an example of a subject part to receive driving force. The cam-like part 192 is formed close to the displacement end 184 of the latching unit 142-4 to be opposite the abutting part 191. The cam-like part 192 is formed into a curved surface responsive to the rotation angle of the finger 121-4.. The cam-like part 192 is formed as a cam as a mechanical element to change the direction of motion. The cam-like part 192 is what is called a plate cam (circumference cam). Alternatively, the cam-like part 192 may be a planar cam such as a grooved cam or a solid cam.

[0156] An angle regulating part 193 is formed on the left side of the finger 121-4 into a projection of a shape responsive to a side surface of the pin 145. A projection 194 is a projecting part formed in a position opposite the cam-like part 192 while a recess 195 is placed between the projection 194 and the cam-like part 192. The projection 194 is formed to project to the left rear side from the pin 144. The projection 194 is formed into a length that avoids contact of the projection 194 with the displacement end 184 when the displacement end 184 moves to the left side and makes the projection 194 abut on the right side surface of the displacement end 184 when the displacement end 184 moves to the right side.

[0157] The recess 195 is formed between the cam-like part 192 and the projection 194. The recess 195 is formed as a substantially U-shaped recess responsive to the shape of the tip of the displacement end 184 to allow the tip of the displacement end 184 to fit in the recess 195.

[0158] The following describes how the finger 121-4 and the driving unit 131-4 behave while the finger 121-4 is to be moved to the front side.

[0159] In this case, a voltage to displace the transmitting part 153-4 to the right side is applied first to the piezoelectric element 141-4 to bend the piezoelectric element 141-4 to the right side.

[0160] Displacing the transmitting part 153-4 to the right side displaces the subject end 181 of the latching unit 142-4 to the right side by the same length as the displacement of the transmitting part 153-4. A length from the hinge part 182 to the subject end 181 is about one-fifth of a length from the hinge part 182 to the displacement end 184. Thus, the displacement end 184 is displaced to the left side (X-axis direction) by a length five times longer than the length of the displacement of the subject end 181 to the right side (X-axis direction). At this time, the left side surface of the beam 183 of the latching unit 142-4 abuts on the pin 147, thereby restricting the position of the beam 183 of the latching unit 142-4 when the beam 183 moves to the left side.

[0161] Moving the displacement end 184 to the left side makes the displacement end 184 press the projecting portion of the cam-like part 192, thereby moving the finger 121-4 to the front side More specifically, when the displacement end 184 presses the cam-like part 192, the finger 121-4 rotates anticlockwise about the pin 144 to move to the front side.. At this time, the abutting part 191 moves to a position where the abutting part 191 abuts on the working needle or the jack

[0162] The angle regulating part 193 is formed into a Projection. Thus, when the finger 21-4 moves to the front side, the angle regulating part 193 abuts on the pin 145 to regulate the angular position of the finger 121-4 such that the finger 121-4 is placed in a given angular position relative to the base 132.

[0163] In this way, the finger 121-4 moves to the front side and the abutting part 191 of the finger 121-4 moves to a position where the abutting part 191 abuts on the working needle or the jack As a result of the movement of the finger 121-4 to the front side, the abutting part 191 abuts on the approaching working needle or jack and then presses or lifts the working needle or the jack.

[0164] While the displacement end 184 has moved to the left side and presses the projecting portion of the cam-like part 192 and the finger 21-4 has moved to the front side, the abutting part 191 and the cam-like part 192 of the finger 121-4 and the displacement end 184, the beam 183, and the hinge part 182 of the latching unit 142-4 are arranged in a substantially linear pattern in the Y-axis direction. As a result of abutting contact of the approaching working needle or jack with the abutting part 191, force applied to the finger 21-4 acts backward, specifically in a substantially linear pattern in the Y-axis direction. Thus, application of force to the finger 121-4 still maintains the positions of the finger 121-4 and the latching unit 142-4 relative to each other and the latching unit 142-4 receives the force applied to the finger 121-4 for displacement of the working needle. Specifically, the latching unit 142-4 receives the force applied to the finger 121-4 for displacement of the working needle to maintain the position of the finger 121-4. Eventually, the force applied to the finger 121-4 is received by the hinge part 182 and the pin 143 and is not transmitted to the piezoelectric element 141-4.

[0165] As described above, if the abutting part 191 of the finger 121-4 is to act to displace the working needle, the latching unit 142-4 holds the finger 121-4 such that the abutting part 191 is in a position where the abutting part 191 acts on the working needle or the jack and receives force applied to the finger 121-4 for displacement of the working needle.

[0166] The following describes how the finger 121-4 and the driving unit 131-4 behave while the finger 21-4 is to be moved to the rear side. For moving the finger 121-4 to the rear side, the finger 121-4 and the driving unit 131-4 behave in the opposite direction but basically in the same manner as the behaviors of the finger 121-4 and the driving unit 131-4 for moving the finger 121-4 to the front side.

[0167] In this case, a voltage to displace the transmitting part 153-4 to the left side is applied first to the piezoelectric element 141-4 to bend the piezoelectric element 141-4 to the left side.

[0168] Displacing the transmitting part 153-4 to the left side displaces the subject end 181 of the latching unit 142-4 to the left side by the same length as the displacement of the transmitting part 153-4. In response, the displacement end 184 is displaced to the right side (X-axis direction). At this time, the right side surface of the beam 18.3 of the latching unit 142-4 abuts on the pin 146, thereby restricting the position of the beam 183 of the latching unit 142-4 when the beam 183 moves to the right side.

[0169] Moving the displacement end 184 to the right side makes the right side surface of the displacement end 184 press the projection 194, thereby moving the finger 121-4 to the rear side.. More specifically, when the right side surface of the displacement end 184 presses the projection 194, the finger 121-4 rotates clockwise about the pin 144 to move to the rear side. At this time, the abutting part 191 moves to a position where the abutting part 191 does not abut on the working needle or the jack.

[0170] The recess 195 is formed as a substantially U-shaped recess responsive to the shape of the tip of the displacement end 184 to allow the tip of the displacement end 184 to fit in the recess 195. Thus, when the displacement end 184 moves to the right side to move the finger 121-4 to the rear side, the tip of the displacement end 184 fits into the recess 195. This allows the finger 121-4 to move to the rear side without interfering with the displacement end 184.

[0171] In this way, the finger 121-4 moves to the rear side and the abutting part 191 of the finger 121-4 moves to a position where the abutting part 191 does not abut on the working needle or the jack. As a result of the movement of the finger 121-4 to the rear side, the abutting part 191 does not abut on the approaching working needle or jack but it lets the working needle or the jack pass therethrough.

[0172] The projection 194 may be omitted. In this case, the movement of the displacement end 184 to the right side does not move the finger 121-4 to the rear side but it keeps the finger 121-4 in its position on the front side. If the abutting part 191 of the finger 121-4 abuts on the approaching working needle or jack in this condition, the finger 121-4 moves to the rear side in response to application of force from the working needle or the jack.

[0173] The cam-like part 192 may have a tiny projection at a boundary with the recess 195 projecting toward the rear side. In this case, if the apex of the displacement end 84 at the tip moves to the left of this projection, force applied to the finger 121-4 for displacement of the working needle moves the displacement end 184 further to the left side. This allows the latching unit 142-4 to more reliably hold the finger 121-4 in a position where the abutting part 91 acts on the working needle or the jack and to receive force applied to the finger 121-4 for displacement of the working needle.

[0174] Meanwhile, if the apex of the displacement end 184 at the tip moves to the right of the aforementioned projection, force applied to the finger 121-4 for displacement of the working needle moves the displacement end 184 further to the right side.. This allows the tip of the displacement end 184 to more reliably fit into the recess 195 to move the finger 121-4 to the rear side, thereby moving the abutting part 91 of the finger 121-4 to a position where the abutting part 91 does not abut on the working needle or the jack.

[0175] As described above, even if displacement of the displacement end 184 is reduced for some reason, the movement of the tip of the displacement end 184 to the left or right of the projection provided to the cam-like part 192 still allows press or lift of the working needle or the jack, or can let the working needle or the jack pass through.

[0176] As described above, the position of the displacement end 184 of the latching unit 142-4 forming the driving unit 131-4 is displaced in a horizontal plane 1 in response to bending of the Piezoelectric element 141-4 to the right or left. The latching unit 142-4 rotates clockwise or anticlockwise about the hinge part 182 hinging on the pin 143, so that the displacement end 184 is displaced at least between two positions on an arc in the horizontal plane 1. Specifically, the driving unit 131-4 generates driving force to cause displacement at least between the two positions on the arc in the horizontal plane 1. The latching unit 142-4 is arranged to extend in the Y-axis direction, making the chord of the arc where the displacement end 184 is placed extend like a straight line in the X-axis direction.

[0177] The position of the abutting part 191 of the finger 121-4 is displaced in the horizontal plane 1 in response to bending of the piezoelectric element 141-4 to the right or left. The finger 121-4 rotates clockwise or anticlockwise about the pin 144, so that the abutting part 191 is displaced at least between two positions on an arc in the horizontal plane 1. Specifically, the abutting part 191 of the finger 121-4 is displaced at least between the two positions on the arc in the horizontal plane 1. The finger 121-4 moves to the front side or to the rear side defined in the Y-axis direction, making the chord of the arc where the abutting part 191 of the finger 121-4 is placed extend like a straight line in the substantially Y-axis direction.

[0178] Specifically, the abutting part 191 of the finger 121-4 is displaced at least between the two positions on the arc having a chord as a straight line extending substantially along the Y axis in a direction crossing the direction of the chord of the arc as a straight line in the X-axis direction on which the displacement end 184 is placed.

[0179] As described above, the driving unit 131-4 generates driving force to cause displacement between two first positions on a first arc in the horizontal plane 1 The finger 121-4 includes the cam-like part 192 as a subject part to receive the driving force, and the abutting part 191 as an action part to act on the working needle or the jack. The abutting part 191 is formed to be opposite the cam-like part 192. The cam-like part 192 is formed into a cam. In response to application of driving force to the cam-like part 192 resulting from displacement to one of the first positions, the abutting part 191 is displaced to one of two second positions on a second arc in the horizontal plane 1 having a chord extending in a direction crossing the direction of the chord of the first arc.

[0180] The finger 121-4 is displaced in the horizontal plane 1 so as to displace the abutting part 191 to one of the two second positions on the second arc in the horizontal plane 1. This can narrow the pitch further compared to the case where a finger is moved up and down. The driving part 131-4 and the finger 121-4 behave so as to be displaced on the respective arcs. Thus, in terms of the length of the displacement of the displacement end 184 or the abutting part 191 and the moving distance of the center of gravity of the displacement end 184 or the abutting part 191 being displaced, the moving distance of the center of gravity can be shortened further compared to the case where the displacement end 184 or the abutting part 191 is displaced in a straight line. This allows behavior at a higher speed.

[0181] The fingers 121-1 to 121-3 are configured and behave in the same manner as the finger 121-4. The latching units 142-1 to 142-3 are configured and behave in the same manner as the latching unit 142-4.

[0182] As described above, driving means and a finger are provided.. The driving means generates driving force to cause displacement between the two first positions on the first arc in a predetermined plane. The finger includes a subject part to receive the driving force, and an action part to act on the working needle or the jack. The action part is formed to be opposite to the subject part. The subject part is formed as a cam. In response to application of driving force to the subject part resulting from displacement to one of the first positions, the action part is displaced to one of the two second positions on the second arc formed in the predetermined plane and having a chord extending in a direction crossing the direction of the chord of the first arc. This allows behavior at a higher speed and can narrow a gap further in the vertical direction between fingers..

[0183] An actuator of a needle selector for a knitting machine may include a driving member that outputs displacement in a uniaxial direction responsive to the quantity of input energy, and a displacement amplifying mechanism that amplifies the displacement output from the driving member The displacement amplifying mechanism may include: a first receiving part arranged on the side of one end portion of the driving member where the driving member is displaced and receiving force resulting from the displacement of the driving member; a second receiving part arranged on the side of an opposite end portion of the driving member where the driving member is displaced, fixed to the needle selector, and receiving force resulting from the displacement of the driving member; a first beam having one end connected to the first receiving part and extending in the uniaxial direction along one side surface of the driving member; a second beam having one end connected to the second receiving part and extending in the uniaxial direction along an opposite side surface of the driving member; a first coupling part coupling an opposite end of the first beam and the second receiving part and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; a third beam extending in the uniaxial direction along a side surface of the second beam opposite a side surface of the second beam close to the driving member; a second coupling part coupling one end of the third beam and an opposite end of the second beam and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; and a third coupling part coupling a position of the side surface of the third beam separated by a given length from one end of the third beam and the first receiving part and being elastically deformed as a point of effort in response to transmission of force resulting from the displacement of the driving member. The displacement amplifying mechanism may output amplified displacement from an opposite end of the third beam. In this case, a width indicating a length in a direction crossing the uniaxial direction can be reduced further to allow behavior at a higher speed. Specifically, a first aspect of this invention is intended for an actuator of a needle selector for a knitting machine. This actuator includes a driving member that outputs displacement in a uniaxial direction responsive to the quantity of input energy, and a displacement amplifying mechanism that amplifies the displacement output from the driving member. The displacement amplifying mechanism includes: a first receiving part arranged on the side of one end portion of the driving member where the driving member is displaced and receiving force resulting from the displacement of the driving member; a second receiving part arranged on the side of an opposite end portion of the driving member where the driving member is displaced, fixed to the needle selector, and receiving force resulting from the displacement of the driving member; a first beam having one end connected to the first receiving part and extending in the uniaxial direction along one side surface of the driving member; a second beam having one end connected to the second receiving part and extending in the uniaxial direction along an opposite side surface of the driving member; a first coupling part coupling an opposite end of the first beam and the second receiving part and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; a third beam extending in the uniaxial direction along a side surface of the second beam opposite a side surface of the second beam close to the driving member; a second coupling part coupling one end of the third beam and an opposite end of the second beam and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; and a third coupling part coupling a position of the side surface of the third beam separated by a given length from one end of the third beam and the first receiving part and being elastically deformed as a point of effort in response to transmission of force resulting from the displacement of the driving member. The displacement amplifying mechanism outputs amplified displacement from an opposite end of the third beam. The actuator according to the first aspect of this invention can reduce a width further to allow behavior at a higher speed. In this case, the driving member can be a piezoelectric element. Alternatively, the driving member can be a piezoelectric element to be deformed in the D33 mode. Alternatively, the driving member can be a magnetostrictive element. Alternatively, the driving member can output displacement using a solenoid. Alternatively, the driving member can output displacement using deformation of a shape-memory alloy.

[0184] A displacement amplifying mechanism of an actuator of a needle selector for a knitting machine may include: a first receiving part arranged on the side of one end portion of a driving member where the driving member is displaced and receiving force resulting from the displacement of the driving member, the driving member outputting the displacement in a uniaxial direction responsive to the quantity of input energy; a second receiving part arranged on the side of an opposite end portion of the driving member where the driving member is displaced, fixed to the needle selector, and receiving force resulting from the displacement of the driving member; a first beam having one end connected to the first receiving part and extending in the uniaxial direction along one side surface of the driving member; a second beam having one end connected to the second receiving part and extending in the uniaxial direction along an opposite side surface of the driving member; a first coupling part coupling an opposite end of the first beam and the second receiving part and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; a third beam extending in the uniaxial direction along a side surface of the second beam opposite a side surface of the second beam close to the driving member; a second coupling part coupling one end of the third beam and an opposite end of the second beam and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; and a third coupling part coupling a position of the side surface of the third beam separated by a given length from one end of the third beam and the first receiving part and being elastically deformed as a point of effort in response to transmission of force resulting from the displacement of the driving member. The displacement amplifying mechanism may output amplified displacement from an opposite end of the third beam. In this case, a width indicating a length in a direction crossing the uniaxial direction can be reduced further to allow behavior at a higher speed. Specifically, a second aspect of this invention is intended for a displacement amplifying mechanism of an actuator of a needle selector for a knitting machine. This displacement amplifying mechanism includes: a first receiving part arranged on the side of one end portion of a driving member where the driving member is displaced and receiving force resulting from the displacement of the driving member, the driving member outputting the displacement in a uniaxial direction responsive to the quantity of input energy; a second receiving part arranged on the side of an opposite end portion of the driving member where the driving member is displaced, fixed to the needle selector, and receiving force resulting from the displacement of the driving member; a first beam having one end connected to the first receiving part and extending in the uniaxial direction along one side surface of the driving member; a second beam having one end connected to the second receiving part and extending in the uniaxial direction along an opposite side surface of the driving member; a first coupling part coupling an opposite end of the first beam and the second receiving part and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; a third beam extending in the uniaxial direction along a side surface of the second beam opposite a side surface of the second beam close to the driving member; a second coupling part coupling one end of the third beam and an opposite end of the second beam and being elastically deformed as a fulcrum in response to transmission of force resulting from the displacement of the driving member; and a third coupling part coupling a position of the side surface of the third beam separated by a given length from one end of the third beam and the first receiving part and being elastically deformed as a point of effort in response to transmission of force resulting from the displacement of the driving member. The displacement amplifying mechanism outputs amplified displacement from an opposite end of the third beam. The displacement amplifying mechanism according to the second aspect of this invention can reduce a width further to allow behavior at a higher speed.

[0185] The needle selector 11 or 101 is described as having four fingers overlapping in the Z-axis direction. However, the number of such fingers is not limited to four. A desired number of such fingers may be provided such as eight, twelve, or sixteen.

[0186] The aforementioned embodiments of this invention are not the only embodiment of this invention. Various changes can be devised within a range that does not deviate from the substance of this invention.

Reference Signs List

[0187] 

11

Needle selector

21-1 to 21-4

Finger

41-1 to 41-4

Piezoelectric element

42-1 to 42-4

Displacement amplifying unit

43 and 44

Pin

45-1 to 45-4

Latching unit

46 to 48

Pin

61

Base part

62

Base part

63

Driving element fixing end

64

Driving element fixing end

65

First point of effort coupling part

66

First fulcrum beam

67

First fulcrum coupling part

68

Second fulcrum beam

69

Second fulcrum coupling part

70

Second point of effort coupling part

71

Displacement beam

72

Displacement end position adjusting part

73

Displacement end

81

Subject end

82

Hinge part

83

Beam

84

Displacement end

91

Abutting part

92

Cam-like part

93

Angle regulating part

94

Projection

95

Recess

101

Needle selector

121-1 to 121-4

Finger

131-1 to 131-4

Driving unit

141-1 to 141-4

Piezoelectric element

142-1 to 142-4

Latching unit

143 to 147

Pin

151-1 to 151-4

Supporting part

152-1 to 152-4

Supporting part

153-1 to 153-4

Transmitting part

181

Subject end

182

Hinge part

183

Beam

184

Displacement end

191

Abutting part

192

Cam-like part

193

Angle regulating part

194

Projection

195

Recess

Claims

1. A needle selector for a knitting machine, comprising:

driving means that generates driving force to cause displacement between two first positions on a first arc in a predetermined plane; and

a finger including a subject part to receive the driving force and an action part to act on a working needle or a jack, the action part being formed to be opposite to the subject part, wherein

the subject part is formed as a cam, and

in response to application of the driving force to the subject part resulting from displacement to one of the first positions, the action part is displaced to one of two second positions on a second arc formed in the predetermined plane and having a chord extending in a direction crossing the direction of the chord of the first arc.

2. The needle selector according to claim 1, wherein the predetermined plane is perpendicular to a moving direction of the working needle when selected.

3. The needle selector according to claim 1, wherein the driving means generates the driving force using deformation of a piezoelectric element.

4. The needle selector according to claim 3, wherein the driving means generates the driving force using deformation of the piezoelectric element in the D33 mode.

5. The needle selector according to claim 3, wherein the driving means generates the driving force using deformation of the piezoelectric element of a bimorph type.

6. The needle selector according to claim 1, wherein the driving means generates the driving force using deformation of a magnetostrictive element.

7. The needle selector according to claim 1, wherein the driving means generates the driving force using a solenoid actuator.

8. The needle selector according to claim 1, wherein the driving means generates the driving force using deformation of a shape-memory alloy.

9. The needle selector according to claim 1, wherein the driving means includes a position holding unit which holds the finger for the action part being in one of the second positions where the action part acts on the working needle or the jack and receives force applied to the finger for displacement of the working needle, when the action part of the finger is to act to displace the working needle.

10. The needle selector according to claim 9, wherein the position holding unit of the driving means does not interfere with displacement of the finger if the working needle is not to be displaced.

11. The needle selector according to claim 1, wherein the driving means includes a displacement amplifying unit that amplifies displacement generated by a driving member and generates the driving force to cause displacement between the first positions on the first arc in the plane..

Drawing