(19)
(11) EP 0 210 790 A2

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
04.02.1987 Bulletin 1987/06

(21) Application number: 86305492.0

(22) Date of filing: 16.07.1986
(51) International Patent Classification (IPC)4D04B 15/78
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 24.07.1985 JP 161965/85

(71) Applicant: WATANABE KUTSUSHITA KOGYO CO. LTD.
Iruma-gun Saitama 354 (JP)

(72) Inventors:
  • Watanabe, Yoshinori
    Yono-shi Saitama (JP)
  • Watanabe, Yuji
    Tokyo (JP)
  • Watanabe, Fumio
    Fujimi-shi Saitama (JP)
  • Watanabe, Toshio
    Iruma-gun Saitama (JP)
  • Watanabe, Chiharu
    Fujimi-shi Saitama (JP)

(74) Representative: Bayliss, Geoffrey Cyril et al
BOULT, WADE & TENNANT 27 Furnival Street
London EC4A 1PQ
London EC4A 1PQ (GB)


(56) References cited: : 
   
       


    (54) Knitting needle driving mechanism of knitting machine


    (57) A knitting needle driving mechanism (11) of a jacquard knitting machine in which a movement of fingers (10) defining a sliding motion of each knitting needle is applied by a bending movement of the finger activated by inputting a pulse emitted from a memory to a piezo-electric member (15) attached to one face or to both faces of the finger.




    Description


    [0001] This invention relates to a knitting needle driving mechanism of a knitting machine.

    [0002] More specifically, this invention relates to a knitting needle driving mechanism of a knitting machine capable of knitting a predetermined pattern by causing or removing engagement between rising cams for applying a sliding movement to a plurality of knitting needles arranged on a needle bed of the knitting machine and rising cam butts of the knitting needles or rising cam butts of jacks engaging with lower ends of the knitting needles on the basis of a predetermined knitting plan emitted from a controller of a knitting machine main body.

    [0003] In a jacquard knitting machine such as a jacquard circular knitting machine, a jacquard flat knitting machine or the like, a knitting needle driving mechanism for transmitting a patterning procedure memorized in a pattern procedure memory such as a pin drum, a tape, a floppy disk or the like for upward or downward movement of the knitting needle has been heretofore used. For example, as illustrated in Figure 12, a jacquard circular knitting machine is usually comprised of a knitting cylinder 2 having a plurality of knitting needles 3, yarn feed devices 8, and a knitting needle driving mechanism 1 for transmitting a patterning procedure memorized in a patterning procedure memory 4 for vertical movement of the knittintg needles. The knitting cylinder 2 is rotated through a transmitting mechanism 7 by a motor 6. The rotation of the knitting cylinder, more exactly, the rotational angle of the knitting cylinder, is detected by a decoder 5 and transmitted to the patterning procedure memory 4. A knitting procedure corresponding to the rotational angle of the knitting cylinder 2 is transferred from the patterning procedure memory 4 to the knitting needle driving mechanism 1. A plurality of yarn 9 is fed through the yarn feed devices 8 to the knitting needles 3.

    [0004] As a knitting needle driving mechanism now in wide use, there is known the knitting needle driving mechanism as shown in Fig. 13, a main portion of which is comprised of a plurality of plates 50 arranged slidably in parallel to each other. In this mechanism, the sliding movement of the plates 50 is based on pins on the pin drum or signals emitted from the computer memory. When a plate 50 moves toward a center of the knitting cylinder 52, a jack 51 engaging with the lower end of the knitting needle moves toward the center of the knitting clyinder, so that a cam butt provided on the lower portion of the jack 51 is disengaged from a rising cam 54. Accordingly, by controlling the sliding movement of the plate 50 by the pins or signals emitted from the memory, the vertical movement of the correspond­ing knitting needle is controlled and a knit cloth having the predetermined pattern can be produced.

    [0005] At present, a high speed drive jacquard knitting machine is desired, and it is necessary to speed up the response of the knitting needle driving mechanism to achieve such a high speed drive knitting machine. However, there is a limit to the increase that can be made in the response speed or the sliding speed of the plates in a knitting needle driving mechanism having the constitution where the plates are slid, such as the known knitting needle driving mechanism. It is possible to obtain a high speed knitting machine by increasing the number of the plates slid at the ordinary sliding speed, but the knitting needle driving mechanism then becomes too large, due to the increased number of plates, so that it becomes difficult to arrange the knitting needle driving mechanism in a narrow space outside the knitting machine.

    [0006] The same applicant as the applicant of the present application proposed a knitting needle driving mechanism provided with a plurality of fingers having one end which can be swung, in Japanese Unexamined Patent Publication (Kokai) No. 60-224845. This knitting needle driving mechanism has a rapid response speed compared to the conventional known knitting needle driving mechanism now in wide use, and further is useful in that the knitting needle driving mechanism can be made smaller and the power consumption thereof decreased.

    [0007] However, in the knitting needle driving mechanism having the sliding type fingers and the swing type fingers as described hereinbefore, the movement of the fingers is caused by applying an attraction force or repelling force from an electromagnet. That is, the sliding movements or the swinging movements of the fingers are performed by applying an electric current to the poles of the electromagnets in such a manner that the poles of the electromagnets are changed from plus to minus, respectively, or vice versa. Therefore, the response speed of the knitting needle driving mechanism activated by the electromagnet has a limit caused by a function of the electromagnet itself, and an optimum high speed of the electromagnet is around 80 cycles per second. Further since the power consumption efficiency of the electromagnet is about 1% and the remainder of the electric current is consumed as heat or the like, there is a problem in that the total consumption of the electric power is extremely high when the knitting needle driving mechanism having the electromagnet is used.

    [0008] Consequently, although the knitting needle driving mechanism having the electromagnet can be used for, e.g., a circular knitting machine for knitting socks, which machine has 240 knitting needles and a rotational speed of 220 r.p.m, it is impossible to apply this knitting needle driving mechanism to a circular knitting machine for knitting panty-hose, wherein the machine has 400 knitting needles and a rotational speed of from 400 r.p.m to 1,000 r.p.m. Therefore, in the existing circumstances, the conventional knitting needle driving mechanism has been used for knitting panty-hose by decreasing the rotational speed of the circular knitting machine to a speed corresponding to an ordinary response speed of the conventional knitting needle driving mechanism.

    [0009] Accordingly, a knitting needle driving mechanism having a high response speed, small size, and low electric power consumption is strongly desired to enable the creation of a high speed jacquard knitting machine.

    [0010] The object of the present invention is to provide a knitting needle driving mechanism having a high response speed, small size, and low electric power consumption for a knitting machine which eliminates the above disadvantage of the conventional known knitting needle driving mechanism.

    [0011] A knitting needle driving mechanism according to the present invention is comprised of a housing, and a plurality of fingers supported in the housing by the rear ends thereof and arranged substantially superimposed at intervals along a sliding direction of the knitting needles. The finger is comprised of a plate having one end provided with an attaching portion to be attached to the housing and another end provided with a guiding portion for guiding a finger butt of the knitting needle or a finger butt of the jack, and a piezo-electric element attached to a face or to both faces of the plate and connected to the controller by means of lead wires.

    [0012] The finger is bent in either an upward direction or a downward direction, or in both directions, about a fulcrum, which is the attaching portion of the finger, to cause or remove engagement between the guiding portion of a front end of the finger and the finger butt of the knitting needle or the finger butt of the jack, when a pulse is input from the controller to the piezo-­electric element in accordance with the procedure corresponding to the predetermined pattern, whereby the formation or the release of engagement between the rising cam and the rising cam butt of the knitting needle or the rising cam butt of the jack is caused by the formation or release of engagement between the guiding portion of the finger and the finger butt of the knitting needle or the finger butt of the jack, and the sliding movement of the knitting needle is thereby defined.

    [0013] In a circular knitting machine, the needle bed, i.e., a knitting cylinder, is rotated on a frame of the knitting machine, and the knitting needle driving mechanism is fixed to the frame of the knitting machine. Therefore, when the knitting needle driving mechanism according to the present invention is used in the circular knitting machine, it is necessary to constitute the knitting needle driving mechanism in such a manner that the guiding portion of the finger advances towards or retreats from a moving locus of the finger butt of the knitting needle or the finger butt of the jack engaging with a lower end of the knitting needle by the swing motion of the finger, before the corresponding knitting needle moves in front of the knitting needle driving mechanism.

    [0014] It is apparent that the knitting needle driving mechanism according to the present invention can be used in a flat knitting machine. In a flat knitting machine, the needle belt is fixed on a frame of the knitting machine, and a slider including the knitting needle driving mechanism and a yarn feed device slides along the needle bed. Therefore, when the knitting needle driving mechanism according to the present invention is used in the flat knitting machine, it is necessary to constitute the knitting needle driving machine in such a manner that the guiding portion of the finger previously advances toward or retreats from a position where the guiding portion of the finger engages with the finger butt of the knitting needle or the finger butt of the jack engaging with a flower end of the knitting needle by the swinging motion of the finger, before the knitting needle driving mechanism slides in front of the corresponding knitting needle.

    [0015] It is preferable that at least one opening is arranged on a portion of the plate of the finger which is provided with the piezo-electric element. Since a weight of the plate having the opening becomes very light, the plate becomes more flexible, so that the plate can be bent by a lower electric voltage. Further, since the piezo-electric element is affixed to the plate with an adhesive, e.g., adhesives of an epoxy group, it is possible to obtain a firm adhesion when the opening is provided on the plate. Most preferably, the piezo-­electric element is affixed to both faces of the plate.

    [0016] Any kind of piezo-electric element can be used so long as the piezo-electric element is an element having an inverse piezo-electric effect. Preferably a piezo-­electric element of a ceramic constituted from a barium titanate or the like is used, to ensure that a lot quantity of the piezo-electric element having a staple quality can be obtained on an industrial scale. Since it is possible to make the piezo-electric element having a high electrostrictive strain by using a thinner plate, preferably a piezo-electric element having a thickness in the order of from 100 µm to 200 µm is used. Further the piezo-electric element may have an elongated shape. A silver paste or the like is baked on both faces of the piezo-electric element to form the electrodes, and these electrodes are connected through lead lines to the controller, respectively.

    [0017] As described hereinbefore, the piezo-electric element is usually affixed to both faces of the plate of the finger by an adhesive. Of course, it is possible to cause the finger to bend about the fulcrum of the housing by using a finger having one piezo-electric element on one face thereof. Further, it is possible to decrease an electric voltage to the imput to the piezo-­electric element when the piezo-electric element is used on both faces of the finger, compared to the case wherein one piezo-electric element is affixed on one face of the finger. Note, when two piezo-electric elements are used for one finger, it is necessary to arrange the two piezo-electric elements on the plate of the finger in such a manner that an orientation between a plus electrode and a minus electrode of each piezo-­electric element is in the same direction.

    [0018] The number of fingers in the knitting needle driving mechanism according to the present invention may be determined in accordance with a required knitting pattern. Since the piezo-electric element has a rapid response speed and it is possible to input a pulse with high frequency to the element, when a pulse of 240 cycles, for example, is input to the element, the knitting needle driving element can drive the knitting needle at a high speed of three times the speed (usually 80 cycles) of a conventional known knitting needle driving mechanism operated by electromagnets. This means that the number of fingers can be decreased to one-third of the number of fingers used in the conventional knitting needle driving mechanism. Further, if the knitting needle driving mechanism according to the present invention which has the same number of fingers as the number of fingers of the conventional knitting needle driving mechanism is used, it is possible to knit a jacquard cloth having a complicated pattern such as a three time pattern, compared with a pattern knitted by using the conventional knitting needle driving mechanism, and it is possible to use this knitting needle driving mechanism with a knitting machine in which a product of the number of knitting needles and a rotational speed of the knitting cylinder is three times that of the conventional knitting machine.

    [0019] Since the finger of the knitting needle driving mechanism according to the present invention is constituted by a thin plate and the piezo-electric element, the height necessary for arranging one finger in the driving mechanism becomes very small and, further, the width of the driving mechanism also becomes very small. Therefore, when the same number of fingers are used in the driving mechanism, the total volume of the driving mechanism becomes very compact. As described hereinbefore, since the knitting needle driving mechanism according to the present invention has a compact volume and a high response speed, this driving mechanism can be also used in a circular knitting machine for knitting panty-hose, in which space it is impossible to attach the conventional knitting needle driving mechanism using the electromagnets with reference to a space to be arranged with the latter driving mechanism.

    [0020] Preferably the plate of the finger is of stainless steel and the guiding portion of the finger is formed as a different member made of a hardened steel having a thicker thickness than that of the plate. A rear end of the finger of the stainless steel is held to the housing, and the guiding member made of the hardened steel is connected to a front end of the plate. It is possible to adopt various methods for connecting the guiding member to the end of the finger. For example, the guiding member may be connected to the end of the finger by an adhesive, a rivet or the like. Further, it may be possible to achieve the connection between them by providing a groove by which a front end of the plate can be inserted at a rear end of the guiding member.

    [0021] Since the guiding member usually impacts on the finger butt of the knitting needle or the jack, abrasion of the guiding member is severe. Further it is necessary to ensure the engagement between the guiding member and the finger butt. To counteract the above, the guiding member should be made of hardened steel and have a thick thickness. Preferably, the guiding member has a thickness of about 1 mm.

    [0022] Preferably, the shape of the end of the finger near to the knitting needle is formed as a hill shape or half hill shape in the plane parallel to the plate of the finger, and it is preferable to make the engagement between the finger butt and the guiding portion of finger along an inclined face of the finger so that the finger butt can be smoothly pushed toward the needle bed of the knitting machine.

    [0023] The controller connected to the piezo-electric elements is a device for memorizing a pattern procedure and inputting a pulse to the plurality of piezo-electric elements on the basis of the memorized pattern procedure, respectively. Since this device is a familiar device in the art, a further detailed explanation thereof will be omitted.

    [0024] Each guiding portion of the plurality of fingers is moved upward or downward on the basis of a signal emitted from the controller to each piezo-electric element of the corresponding finger.

    [0025] A length of the amplitude of the upward and downward movement of the guiding portion of the finger is deter mined in accordance with a height of the rising cam butt in the direction parallel to the movement of the knitting needle. A length of from 1.5 mm to 2.0 mm is usually adopted as the length of amplitude of the upward and downward movement of the guiding portion of the finger.

    [0026] The finger butt of the knitting needle or the jack strikes on the guiding portion of the finger supported by the rear end thereof from a lateral direction, i.e. the direction substantially perpendicular to a lengthwise direction of the finger, and in a plane including the finger. Therefore, if the finger butt can not move smoothly toward the needle bed, due to a problem in the knitting needle or the jack, it could be seriously damaged by the strong force pushing the finger in the lateral direction. To solve this problem, preferably the housing includes a needle bed opposing member elongated in a direction parallel to the sliding direction of the knitting kneedle in the needle bed at a place adjacent to the guiding portion of a plurality of fingers. The needle bed opposing member is provided with a pair of finger-guiding faces for slidably supporting both side faces of the guiding portion of the finger through the predetermined space in the direction perpendicular to a plane including the plate of the finger, and at least one finger butt guiding face extending from the finger guiding face in the direction parallel to the swinging direction of the finger and in the direction away from the guiding portion of the finger. The finger butt guiding face may be formed as a face parallel to the above-mentioned lateral direction, as a face extending from the parallel face, e.g., going toward the needle bed, or as a face extending from the parallel face, e.g., going away from the needle bed. Thus when the finger butt of the knitting needle or the jack jumps out in the direction away from the needle bed during a knitting operation, it is possible to push the finger butt into a suitable position by means of the needle bed opposing member having the finger guiding face and finger butt guiding face. Further, since the guiding portion of the finger is supported in the lateral direction by the finger guiding face of the needle bed opposing member, even if there is problem in pushing the finger butt toward the needle bed, the finger is not damaged.

    [0027] The power consumption efficiency of the knitting needle driving mechanism according to the present invention is high, i.e., about 70%, and this value is one to several tens higher than power consumption efficiency of the conventional knitting needle driving mechanism using the electromagnet.

    [0028] The following is a description of some specific embodiments of the inventuon, reference being made to the accompanying drawings in which:

    Figure 1 is a partially sectioned front elevation view of an embodiment of a knitting needle driving mechanism according to the present invention;

    Fig. 2 is a side view of the knitting needle driving mechanism illustrated in Fig. 1;

    Fig. 3 is a plan view of a finger in the knitting needle driving mechanism illustrated in Fig. 1;

    Fig. 4 is a front elevation of the finger illustrated in Fig. 3;

    Fig. 5 is a perspective view illustrating a relationship of a position between the finger and a needle bed opposing member;

    Fig. 6 is a front elevation view of an operational state of the finger when a pulse is not input to a piezo-electric element;

    Fig. 7 is a front elevation view of an operational state of the finger when a pulse is input to the piezo-­electric element and the finger is bent;

    Fig. 8 is a plan view of another embodiment of the finger according to the present invention;

    Fig. 9 is a front elevation view of the finger illustrated in Fig. 8;

    Fig. 10 is a plan view of still other embodiment of the finger according to the present invention;

    Fig. 11 is a front elevation view of the finger illustrated in Fig. 10;

    Fig. 12 is a perspective view of an example of a conventional known jacquard circular knitting machine; and

    Fig. 13 is a partial cross-sectional side view of a conventional known knitting needle driving mechanism.



    [0029] Before proceeding to the detailed description of the various specific embodiments illustrated, it should be noted that although the knitting needle driving mechanism of the embodiments is described in conjunction with a circular knitting machine, it will be apparent that the knitting needle driving mechanism is equally applicable to a flat knitting machine.

    [0030] As illustrated in Fig. 1,the knitting needle driving mechanism 1 of the embodiment is comprised of a plurality of fingers 10 and a housing 30 accommodating the fingers 10. In the embodiment illustrated in Fig. 1, eight fingers are superimposed in the direction parallel to an axis of a knitting cylinder as well as a sliding direction of the knitting needle in a state having spaces between each finger. The housing 30 has a rectangular shape constituted by a rear wall 31, front wall 32, an upper wall 33, and a lower wall 34. A rear end 12 (see Fig. 3) of each finger 10 is supported in the rear wall 31 and the rear end 12, i.e, the attaching portion, serves as a fulcrum of a bending motion of the finger 10.

    [0031] As illustrated in Fig. 2, the front wall 32 is provided with an opening 30 through which guiding elements 20 arranged on each end of each finger 10 can protrude, and grooves 36 having a width corresponding to a rising distance and a descending distance of the guiding element caused by the bending motions of the fingers, respectively, and arranged on a vertical wall of the opening 30.

    [0032] As illustrated in detail in Figs. 3 and 4, the finger 10 is comprised of a plate of stainless steel SOS 301 and a thickness of 200 µ a guiding element 20 attached to an end 13 opposite to the finger attaching portion 12 of the finger 10, and piezo-electric elements 15 and 16 attached to an upper face and an under face of the plate 11. For example, a length of the plate 11 is 40 mm and a width of a portion to which with the piezo-electric elements are attached is 15 mm.

    [0033] The guiding element 20 is made of a hardened steel having a thickness of 1 mm and attached to the end 13 of the plate 11 by means of an adhesive. The guiding element 20 is provided with inclined faces 21a and 21b engaging with a finger butt of the knitting needle or a finger butt of a jack engaging with a lower end of the knitting needle, these faces having a shape such that a hill shape is formed by both inclined faces 21a and 21b, and includes side faces 22a and 22b opposing the front walls 32 of the housing 30 as illustrated in Fig. 5.

    [0034] The piezo-electric elements 15 and 16 are adhered to an upper face and an lower face by means of an epoxy group adhesive, as illustrated in Figs. 3 and 4. The piezo-electric element is a ceramic plate produced by sintering a barium titanate, and having an inverse piezo-electric effect and a thickness of 100µm. The piezo-electric element has a rectangular shape and silver plated layers serving as electrical connections with one end of the lead wires 17 and 18 are arranged on both surfaces thereof. The other ends of the lead wires 17 and 18 are connected to a controller 4. It is possible to use a lead wire connected to an upper face 15a of the piezo-electric element 15 and an under face 16a of the piezo-electric element 16, respectively. In this case, the finger 11 may be served as an earth.

    [0035] Although a plate having two piezo-electric elements 15 and 16 on both faces is illustrated in Fig. 4, a plate having one piezo-electric element on one face thereof may be used as illustrated in Figs. 10 and 11.

    [0036] An opening 14 may be arranged in an area to which the piezo-electric element 15 and 16 of the plate 11 of the finger 10 are attached, as illustrated in Figs. 8 and 9. The shape, size and number of the openings 14 are optionally selected, and the attachment between the piezo-electric element 15, and 16 and the plate 11 performed by the adhesive is firmly obtained by the opening 14. The opening 14 serves also to make the weight of plate lighter, and thus the plate 11 become more flexible.

    [0037] Each plus electrode and each minus electrode of two piezo-electric element must be arranged in the same direction when a piezo-electric element is arranged on the upper face and the under face of the plate, respectively. For example, in Fig. 4, when the piezo-­electric element 15 is arranged on the plate 11 so that the upper face 15a thereof is the plus electrode and the under face15 is the minus electrode, the piezo-electric element 15 must be arranged on the plate 11 so that the upper face 16b is the plus electrode and the under face 16a is the minus electrode.

    [0038] The controller 4 is comprised of a memory memorizing a predetermined pattern knitting plan and a device emitting pulses to plurality of piezo-electric elements on the basis of the memorized pattern knitting plan.

    [0039] Preferably a needle bed opposing member 37 extending at a place adjacent to the guiding elements 20 of the fingers 11 in a sliding direction of the knitting needle is provided to protect the fingers and to make smooth engagement between the guiding element 20 of the finger 11 and the finger butt of the knitting needle or the jack smooth, as illustrated in Fig. 5. This needle bed opposing member 37 may be provided as a vertical member of the front wall 32 of the housing 30, and includes a finger guiding face 36 and a finger butt guiding face 37. The finger guide face 36 is arranged such that the face 36 opposes, through a small gap, a side face of the guiding element 20, so that the guiding element 20 can slide against the finger guide face 36. The finger butt guiding face 37 serves to previously push the finger butt protruding largely in the direction away from the knitting cylinder into a normal position. Note, the above needle bed opposing member is not an indispensable member in the knitting needle driving mechanism according to the present invention.

    [0040] The knitting needle driving mechanism according to the present invention can be manufactured in a small size. For example, the knitting needle driving mechanism of the embodiment illustrated in Figs. 1 and 2 has a height of 55 mm, a width of 30 mm, and a length, i.e., the lengthwise distance of the finger, of 50 mm. But a conventional known knitting needle driving mechanism having the same number of fingers as that of the knitting needle driving mechanism of the present invention, i.e., eight fingers, and operated by electromagnets, has a height of 80 mm, a width of 45 mm, and a length of 100 mm. That is the knitting needle driving mechanism of the present invention can be made to have a volume of about 25% compared with a volume of the conventional known knitting needle driving mechanism.

    [0041] The operation of the knitting needle driving mechanism of the embodiment will be now described with reference to Figs. 6 and 7.

    [0042] Figure 6 shows a state wherein a pulse is not input to the piezo-electric element of the finger 11, and Fig. 6 shows a state wherein a pulse is input to the piezo-electric element. In the state illustrated in Fig. 6, the finger butt 56 of the jack 51 engages with the guiding element 20 to push the jack 51 to the right, so that a rising cam butt 53 arranged on a lower end of the jack 51 cannot engage with a rising cam 54, and the jack 51 and a knitting needle engaging with an upper end of the jack 51 are not subjected to a rising movement. Therefore a knitting loop is not formed in this knitting needle.

    [0043] In the state illustrated in Fig. 7, since the guiding element 20 of the finger 10 has not entered a moving path of the finger butt 56, the jack 51 is kept in the vertical position, so that the rising cam butt 53 engages with the rising cam 54 to push the jack 51 upward. Thus the knitting operation is applied to a knitting needle engaging with the upper end of the jack 51.


    Claims

    1. A knitting needle driving mechanism of a knitting machine capable of knitting a predetermined pattern by causing or removing engagement between rising cams for applying a sliding movement to a plurality of knitting needles arranged on a needle bed of the knitting machine and rising cam butts of the knitting needles or rising cam butts of jacks engaging with lower ends of the knitting needles on the basis of signals for a predetermined knitting plan emitted from a controller of a knitting machine main body: characterized in that
    said knitting needle driving mechanism is comprised of a housing, and a plurality of fingers supported in the housing by rear ends thereof and arranged substantially superimposed at intervals along a sliding direction of the knitting needles;
    each of said plurality of fingers is comprised of a plate having one end provided with an attaching portion to be attached to the housing and another end provided with a guiding portion for guiding a finger butt of the knitting needle or a finger butt of the jack, and piezo-electric element(s) attached to a face or both faces of the plate and connected to the controller by means of lead wires;
    said fingers being bent in an upward direction and a downward direction or in both directions, about a fulcrum which is formed by the attaching portion of the finger to cause or remove engagement between the guiding portion of a front end of the finger and the finger butt of the knitting needle or the finger butt of the jack, when a pulse is input from the controller to the piezo-electric element in accordance with the procedure corresponding to the predetermined pattern, thereby the formation or the release of engagement between the rising cam and the rising cam butt of the knitting needle or the rising cam butt of the jack is caused by the formation or the release of engagement between the guiding portion of the finger and the finger butt of the knitting needle or the finger butt of the jack, and the sliding movement of the knitting needle is thus defined.
     
    2. A knitting needle driving mechanism according to claim 1, characterized in that said knitting machine is a circular knitting machine having a needle cylinder rotating against a frame of the knitting machine and at least one knitting needle driving mechanism arranged on the frame, and the knitting needle driving mechanism being constituted such that the guiding portion of the finger advanced into or removes from a moving locus of the finger butt of the knitting needle or the finger butt of the jack engaging with a lower end of the knitting needle by the swing motion of the finger before the corresponding knitting needle moves in front of the knitting needle driving mechanism.
     
    3. A knitting needle driving mechanism according to claim 1, characterized in that said knitting machine is a flat knitting machine having a needle bed fixed to a frame of the knitting machine and at least one knitting needle driving mechanism capable of sliding along the needle bed, and the knitting needle driving mechanism being constituted such that the guiding portion of the finger previously advances toward or retreats from a position where the guiding portion of the finger engages with the finger butt of the knitting needle or the finger butt of the jack engaging with a lower end of the knitting needle by the swinging motion of the finger before the knitting needle driving mechanism slides in front of the corresponding knitting needle.
     
    4. A knitting needle driving mechanism according to any one of claims 1 to 3, characterized in that said housing includes a needle bed opposing member extending at a place adjacent to the guiding portions of the fingers in the direction parallel to the sliding direction of the knitting needle, and said needle bed opposing member is provided with a pair of finger guiding faces for slidably supporting both side faces of the guiding portion of the finger in the swinging direction of the finger and at least one finger butt guiding face extending from the finger guiding face in the direction parallel to the swinging direction of the finger and in the direction away from the guiding portion of the finger.
     
    5. A knitting needle driving mechanism according to any one of claims 1 to 3, characterized in that at least one opening is arranged on a portion of the plate of the finger which is provided with the piezo-electric element.
     
    6. A knitting needle driving mechanism according to any one of claims 1 to 3, or claim 5, characterized in that the plate of the finger is made of a stainless steel and the guiding portion is formed as a different member made of a hardened steel having a thicker thickness than that of the plate and attached to the front end of the plate.
     




    Drawing