Needle selecting device for a circular knitting machine

Abstract

 A needle selecting device for a circular knitting machine includes a first mounting post (10) having a plurality of longitudinally extending guiding slots (13) to permit guiding rods (21) of a plurality of needle selecting units (20) to be moved therealong by a first back pressure generated as a result of a first shot of pressurized air/gas, and a gate unit (4) including a gate member (41) which is uprightly moved by a second back pressure generated as a result of a second shot of the pressurized air/gas between blocked and unblocked position so as to permit the guiding rod (21) to make full-stroke and partial-stroke movements, thereby engaging with short and long pattern butts (320, 310) of a selected needle jack (300) for performing a variety of hosiery.

Description

[0001] This invention relates to a circular knitting machine, more particularly to a needle selecting device for a circular knitting machine, especially a hosiery knitting machine.

[0002] In a hosiery knitting machine, a needle selecting device is used to select vertical motions of working needles fitted in a plurality of vertical grooves formed in an outer surrounding surface of a needle cylinder, so that a fabric of a desired knit texture can be obtained. A plurality of needle jacks are disposed in the vertical grooves to underlie the corresponding working needles. When activated, the needle jacks transmit a lifting force to displace the corresponding working needles to a higher position for knitting purposes. When the needle jacks are not activated, the working needles are allowed to remain idle in a lower position.

[0003] A conventional needle selecting device generally has a plurality of engaging slides for selectively engaging pattern butts of needle jacks. The engaging slides are activated by means of an electromagnetic device or a pneumatically powered device, such as those disclosed in U.S. Patent No. 5,802,877, Taiwanese Publication No. M274374, and Taiwanese Publication No. 511664. Although the engaging slides can be accurately and desirably selected by virtue of the electromagnetic device to displace to a predetermined position so as to timely engage a selected one of the pattern butts of the needle jacks, the provision of the electromagnetic device renders the needle selecting device complicated in construction and hence difficult to fabricate. Moreover, with the provision of the electromagnetic device, the selection of the needle jacks in the needle cylinder is very limited so that there is little variety in the knit texture. On the other hand, with the provision of a pneumatically powered device, although each engaging slide can be actuated by two pneumatic power supply lines to perform long and short strokes, the needle selecting device will have a relatively large number of component parts, which undesirably renders the structure of the needle selecting device complicated, thereby increasing the manufacturing costs.

[0004] An object of the present invention is to provide a needle selecting device which has a simple construction that is easy to fabricate and assemble and which can perform multiple strokes of varying length.

[0005] According to this invention, the needle selecting device includes a first mounting post, a second mounting post, a plurality of needle selecting units, a gate post, a second output port, and a gate unit.

[0006] The first mounting post is disposed proximate to a needle cylinder of a circular knitting machine, and has first front and rear surfaces opposite to each other in a longitudinal direction radial to an upright axis of the needle cylinder. The first front surface has a plurality of guiding slots which are uprightly displaced from one another, and which respectively extend through the first rear surface in the longitudinal direction.

[0007] The second mounting post is spaced apart from the first mounting post in the longitudinal direction, and has second front and rear surfaces. The second front surface has a plurality of first output ports which are uprightly displaced from one another, and which are respectively aligned with the guiding slots to establish a plurality of reciprocating paths, respectively.

[0008] Each of the needle selecting units includes an engaging slide, a guiding rod, and a first biasing member. The engaging slide is configured to permit one of short and long pattern butts of a selected needle jack to slide thereon. The guiding rod is guided and movable along the corresponding guiding slots, and has a holding end which extends outwardly of the first front surface to connect the engaging slide, and an actuated end which is disposed downstream of the corresponding first output port, and which is actuated by a first back pressure generated as a result of a first shot of pressurized air/gas through the corresponding first output port for making a full-stroke movement along the corresponding reciprocating path to move the engaging slide from a normal position to a fully extended position, where the engaging slide is engaged with the short pattern butt of the selected needle jack. The first biasing member is disposed to bias the guiding rod to retrieve the full-stroke movement immediately after the cessation of the first back pressure so as to move the engaging slide to the normal position.

[0009] The gate post is disposed between the first rear surface and the second front surface, and extends uprightly and offset from the reciprocating paths.

[0010] The second output port is disposed to communicate with a pressurized air/gas source for releasing a second shot of pressurized air/gas.

[0011] The gate unit includes a gate member and a second biasing member. The gate member includes a bar body, a plurality of blocking fins, and an actuated arm. The bar body extends uprightly, and is mounted on, and uprightly movable relative to the gate post between blocked and unblocked positions. The blocking fins are uprightly displaced from one another, and extend from the bar body toward the reciprocating paths such that, when the bar body is in the blocked position, the guiding rod of each needle selecting unit is coupled by one of the blocking fins so as to be refrained from making the full-stroke movement, thereby permitting the engaging slide to be displaced only to a partially extended position where the engaging slide is engaged with the long pattern butt of the selected needle jack. The actuated arm is disposed on the bar body and downstream of the second output port to be actuated by a second back pressure generated as a result of the second shot of pressurized air/gas so as to move the bar body from the blocked position to the unblocked position to thereby permit the guiding rod to make the full-stroke movement. The second biasing member is disposed to bias the bar body to the blocked position.

[0012] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of the preferred embodiment of a needle selecting device according to this invention;

Fig. 2 is an exploded perspective view of the preferred embodiment viewed;

Fig. 3 is another exploded perspective view of the preferred embodiment;

Fig. 4 is a sectional view of the preferred embodiment;

Fig. 5 is a sectional view taken along line V-V of Fig. 4;

Fig. 6 is a sectional view taken along line VI-VI of Fig. 5; and

Figs. 7 to 11 is a fragmentary perspective view showing operation of the preferred embodiment.

[0013] Referring to Figs. 1 to 5, the preferred embodiment of a needle selecting device for a circular knitting machine according to the present invention is adapted to be mounted adjacent to a needle cylinder 200 of the circular knitting machine. The needle cylinder 200 is rotatable about an upright axis, and has a plurality of needle jacks 300 angularly displaced and disposed in an outer surface thereof to respectively underlie working needles (not shown) . For example, each needle jacks 300 has short and long pattern butts 320, 310 extending radially and outwardly of the needle cylinder 200. The needle selecting device according to this invention is shown to comprise a first mounting post 10, a second mounting post 30, a plurality of needle selecting units 20, and a gate unit 40.

[0014] The first mounting post 10 is adapted to be disposed proximate to the needle cylinder 200, and has first front and rear surfaces 11, 12 opposite to each other in a longitudinal direction (L) radial to the upright axis of the needle cylinder 200. The first front surface 11 has a plurality of guiding slots 13 which are uprightly displaced from one another, and which respectively extend through the first rear surface 12 in the longitudinal direction (L), and a plurality of guiding grooves 14 which are uprightly displaced from one another and which are respectively communicated with the guiding slots 13. A gate post 18 is disposed rearwardly of the first rear surface 12, and extends uprightly. The gate post 18 has a plurality of sliding grooves 15 which are uprightly displaced from one another and each of which extends in the longitudinal direction (L) to have front and rear groove sides 152, 151, and an upright slot 16 which extends uprightly and which is communicated with the sliding grooves 15. In this embodiment, the gate post 18 and the first mounting post 10 are integrally formed with each other.

[0015] The second mounting post 30 is disposed rearwardly of the gate post 18, and has second front and rear surfaces 311, 312 opposite to each other. The second front surface 311 has a plurality of first output ports 313 which are uprightly displaced from one another, and which are respectively aligned with the guiding slots 13 to establish a plurality of reciprocating paths, respectively, in the longitudinal direction (L). The reciprocating paths are disposed offset from the upright slot 16 in the gate post 18. A plurality of first adaptors 32 are respectively disposed upstream of the first output ports 313 for coupling with a pressurized air/gas source to supply a first shot of pressurized air/gas into the reciprocating paths.

[0016] Each of the needle selecting units 20 includes an engaging slide 22, a guiding rod 21, and a first biasing member 25. The engaging slide 22 is configured to permit one of the short and long pattern butts 320, 310 of a selected needle jack 300 to slide thereon. The guiding rod 21 is guided and movable along the corresponding guiding slot 13, and has a holding end 23 which extends outwardly of the first front surface 11 to connect the engaging slide 22, and which is configured to be guided and movable in the corresponding guiding groove 14, and an actuated end which is disposed downstream of the corresponding first output port 313, and which has a retained fin 24 extending toward the upright slot 16 to be slidable in the corresponding sliding groove 15. Preferably, the retained fin 24 has front and rear retained surfaces with taper segments 241. Thus, the guiding rod 21 is actuated by a first back pressure generated as a result of the first shot of pressurized air/gas through the corresponding first output port 313 for making a full-stroke movement along the corresponding reciprocating path to move the engaging slide 22 from a normal position to a fully extended position, where the engaging slide 22 is engaged with the short pattern butt 320 of the selected needle jack 300. The first biasing member 25 is sleeved on the guiding rod 21 and is disposed between the first rear surface 12 and the retained fin 24 to bias the guiding rod 21 to retrieve the full-stroke movement immediately after the cessation of the first back pressure so as to move the engaging slide 22 to the normal position.

[0017] The gate unit 40 includes a mount 42, a gate member 41, a second biasing member 43, and upper and lower limit blocks 413, 414. The mount 42 is affixed to the first mounting post 10, and has a second output port 421 and a second adaptor 422 disposed upstream of the second output port 421 for coupling with the pressurized air/gas source to release a second shot of pressurized air/gas. The gate member 41 includes a bar body 411, a plurality of blocking fins 415, and an actuated arm 412.

[0018] The bar body 411 extends uprightly, and is mounted in the upright slot 16 to be uprightly movable between blocked and unblocked positions. The blocking fins 415 are uprightly displaced from one another by a plurality of gaps 416, and extend from the bar body 411 toward the reciprocating paths. Each of the blocking fins 415 has a taper segment 417 for facilitating engagement with the taper segment 241 of the corresponding retained fin 24. The actuated arm 412 is disposed on the bar body 411 opposite to the blocking fins 415 and downstream of the second output port 421 to be actuated by a second back pressure generated as a result of the second shot of pressurized air/gas so as to move the bar body 411 from the blocked position to the unblocked position. The second biasing member 43 is disposed to bias the bar body 411 to the blocked position. The upper and lower limit blocks 413, 414 are disposed to limit the movement of the bar body 411.

[0019] Referring to Figs. 4 to 7, when the guided rod 21 is in the normal position, i.e., no pressurized air/gas is supplied in the first and second output ports 313, 421, the engaging slides 22 are remote from the needle cylinder 200 to disengage from the butts 310, 320 of a needle jack 300 so as to keep the needle jack 300 to remain rested at a lower position, and the bar body 411 is in the blocked position.

[0020] Referring to Figs. 4, 5 and 8, when the first back pressure generated as a result of the first shot of the pressurized air/gas is introduced in the selected reciprocating path through one first adaptor 32, the guiding rod 21 is actuated to move forwardly such that the retained fin 24 is urged to abut against the corresponding blocking fin 415. At this stage, the engaging slide 22 is permitted to move only to a partially extended position, where the engaging slide 22 is engaged with the long pattern butt 310 of the selected needle jack 300, thereby transmitting a lifting force to displace the corresponding needle above the selected needle jack 300 to a higher position for working.

[0021] Referring to Figs. 4 to 6, 9 and 10, when the second back pressure generated as a result of the second shot of the pressurized air/gas is introduced in the second output port 421 through the second adaptor 422, the gate member 41 is moved downwardly to the unblocked position, where the gap 416 is aligned with the retained fin 24. Subsequently, when the first back pressure is introduced in the first output port 313 to move the corresponding guiding rod 21 forwardly, the retained fin 24 is brought to slip over and pass through the corresponding gap 416 to abut against the front groove side 152 so as to permit the guiding rod 21 to make the full-stroke movement, and the engaging slide 22 is engaged with the short pattern butt 320 of the selected needle jack 300, thereby transmitting a lifting force to displace the corresponding needle above the selected needle jack 300 to a higher position for working. Thereafter, referring to Fig. 11, the introduction of the second back pressure is stopped, the gate member 41 is urged to snap back to the blocked position by the biasing force of the second biasing member 43, and the corresponding blocking fin 415 is brought to slidingly engage with the rear retained surface of the retained fin 24, thereby ensuring the displacement of the engaging slide 22 to the fully extended position. When the pressurized air/gas source is supplied to the second output port 421 to move the gate member 41 downwardly to the unblocked position, the guiding rod 21 is moved back to the normal position (as shown in Fig. 7) by the biasing force of the first biasing member 25 ready for the next needle selecting operation.

[0022] As illustrated, by provision of the gate member 41 and the first and second output ports 313, 421, the needle selecting units 20 can be controlled and operated to perform full-stroke and partial-stroke movements. Moreover, since the guided rods 21 are guided by the guiding slots 13 formed in the first mounting post 10 to move the engaging slides 22, the needle selecting device according to this invention, as compared with the prior art, is simple in construction that is easy to fabricate and assemble with relativelylow manufacturing costs.

Claims

1. A needle selecting device for a circular knitting machine which includes a needle cylinder (200) with an upright axis, and a plurality of needle jacks (300) angularly displaced and disposed in the needle cylinder (200) to respectively underlie needles, each of the needle jacks (300) having short and long pattern butts (320, 310) extending radially and outwardly of needle cylinder (200), characterized by said needle selecting device comprising:

a first mounting post (10) adapted to be disposed proximate to the needle cylinder (200), and having first front and rear surfaces (11, 12) opposite to each other in a longitudinal direction (L) radial to the upright axis of the needle cylinder (200), said first front surface (11) having a plurality of guiding slots (13) which are uprightly displaced from one another, and which respectively extend through said first rear surface (12) in the longitudinal direction (L);

a second mounting post (30) which is spaced apart from said first mounting post (10) in the longitudinal direction (L), and which has second front and rear surfaces (311, 312) opposite to each other, said second front surface (311) having a plurality of first output ports (313) which are uprightly displaced from one another, and which are respectively aligned with said guiding slots (13) to establish a plurality of reciprocating paths, respectively;

a plurality of needle selecting units (20), each including

an engaging slide (22) configured to permit one of the short and long pattern butts (320, 310) of a selected needle jack (300) to slide thereon,

a guiding rod (21) guided and movable along a corresponding one of said guiding slots (13), and having a holding end (23) which extends outwardly of said first front surface (11) to connect said engaging slide (22), and an actuated end which is disposed downstream of a corresponding one of said first output ports (313), and which is actuated by a first back pressure generated as a result of a first shot of pressurized air/gas through said corresponding first output port (313) for making a full-stroke movement along the corresponding reciprocating path to move said engaging slide (22) from a normal position to a fully extended position, where said engaging slide (22) is engaged with the short pattern butt (320) of the selected needle jack (300), and

a first biasing member (25) disposed to bias said guiding rod (21) to retrieve the full-stroke movement immediately after the cessation of the first back pressure so as to move said engaging slide (22) to the normal position;

a gate post (18) disposed between said first rear surface (12) and said second front surface (311), and extending uprightly and offset from the reciprocating paths;

a second output port (421) disposed to communicate with a pressurized air/gas source for releasing a second shot of pressurized air/gas; and

a gate member (41) including

a bar body (411) which extends uprightly, and which is mounted on, and uprightly movable relative to said gate post (18) between blocked and unblocked positions,

a plurality of blocking fins (415) which are uprightly displaced from one another, and which extend from said bar body (411) toward the reciprocating paths such that, when said bar body (411) is in the blocked position, said guiding rod of each needle selecting unit (20) is coupled by oneofsaidblockingfins (415) so as to be refrained from making the full-stroke movement, thereby permitting said engaging slide (22) to be displaced only to a partially extended position where said engagingslide (22) is engaged with the long pattern butt (310) of the selected needle jack (300), and

an actuated arm (412) which is disposed on said bar body (411) and downstream of said second output port (421) to be actuated by a second back pressure generated as a result of the second shot of pressurized air/gas so as to move said bar body (411) from the blocked position to the unblocked position to thereby permit said guiding rod (21)

to make the full-stroke movement; and

a second biasing member (43) disposed to bias said bar body (411) to the blocked position.

2. The needle selecting device according to Claim 1, characterized in that said actuated end of said guiding rod (21) of each needle selecting unit (20) has a retained fin (24) which extends toward said bar body (411), and which is configured to mate with and abut against said corresponding blocking fin (415) when said bar body (411) is in the blocked position.

3. The needle selecting device according to Claim 2, characterized in that said retained fin (24) has front and rear retained surfaces such that said front retained surface is brought to slip over and pass said corresponding blocking fin (415) when said bar body (411) is actuated to move downwardly to the unblocked position to unblock the full stroke movement of said guiding rod (21), and such that, once said bar body (411) is subsequently urged to snap back to the blocked position by the biasing force of said second biasing member (43), said corresponding blocking fin (415) is brought to slidingly engage with said rear retained surface, thereby ensuring the displacement of said engaging slide (22) to the fully extended position.

4. The needle selecting device according to Claim 3, characterized in that each of said front and rear retained surfaces of said retained fin (24) and each of said blocking fins (415) respectively have taper segments (241,417) for facilitating sliding engagement with each other.

5. The needle selecting device according to Claim 2, characterized in that said gate post (18) has a plurality of sliding grooves (15) which are uprightly displaced from one another and each of which extends in the longitudinal direction (L) to respectively accommodate said retained fin (24) of said guiding rods (21), and an upright slot (16) which extends uprightly and which is communicated with said sliding grooves (15) to accommodate said bar body (411) to permit movement of said bar body (411).

6. The needle selecting device according to Claim 5, characterized in that said gate post (18) and said first mounting post (10) are integrally formed with each other.

7. The needle selecting device according to Claim 1, characterized in that said first front surface (11) of said first mounting post (10) has a plurality of guiding grooves (14) which are uprightly displaced from one another and which are respectively communicated with said guiding slots (13), said holding end (23) of said guiding rod (21) being configured to be guided and movable in a respective one of said guiding grooves (14) .

8. The needle selecting device according to Claim 1, characterized in that said actuated arm (412) of said gate member (41) is disposed opposite to said blocking fins (415).

Drawing