GB2160231A - Improvements relating to cam arrangement of knitting machine - Google Patents

Abstract

A cam arrangement of a hand knitting machine includes means (29) for camming a mislifted needle 40 below the needle raiser (26) and needle lowerers (23) and (24), thereby preventing the needle from colliding with them. Furthermore, the cam arrangement includes a lifting member which is used to make the needle raiser protrude from or retract into the base plate (20) and which engages or releases the head of a spring loaded bolt supporting the raiser (26). The cams (23, 24) are controlled by the engagement on pins (271) of cam faces (332) on members (32) which are guided by screws (31) on base plate (20) engaging in grooves (321) in the members. To prevent impacts between the screw and the groove end stops (323) on the members abut first against the baseplate (20). <IMAGE>

Description

SPECIFICATION Improvement relating to cam arrangement of knitting machine This invention relates to improvements on the cam arrangement of a flat knitting machine, particularly to-a hand flat knitting machine.

In a typical hand knitting machine, the carriage movably supported on the needle bed includes a base plate 10, as shown in Fig. 1, on which are mounted an upper needle raiser and a lower needle raiser 1 3 and 14, two needle lowerers 11 and 12, and two stitch cams 1 5 and 1 6 movable in a plane parallel to the base plate. During the knitting operation, the needle raisers and needle lowerers are used for needle selection, and the stitch cams are used for adjustment of the tightness of the knitting.It is found that such cam arrangement suffers from disadvantages that, if a needle is mislifted due to the faulty operation of the operator when an adjacent needle is selectedly lifted, the mislifted needle usually collides with the cam 11, 1 2 or 14, harming the perfection of the needle groove and cams, and even resulting in the breakage of the needle.

During plain knitting operation, the cam 1 4 must be retracted into the base plate 1 0. To achieve this retracted position, it is necessary to detach the cam 14 and the related parts from the guide plate provided above the base plate 1 0. The detaching causes inconvenience to the operator and, in addition, the pattern knitting will be rendered impossible after detaching. An alternative way to make the cam 1 4 retracted in the base plate is to lift the upwardly extending spring-loaded guide bolt which is attached to the cam 1 4 by one hand of the operator of which another hand is operating the machine for plain knitting.

When the operator intends to proceed with the pattern knitting, the guide bolt is released from his hand to return the cam 14 to its prior position. This method is also inconvenient and may cause the operator to become easily fatigued. The needle raiser will undesirably protrude from the base plate due to the dropping of the guide bolt from the tiring hand, thereby causing demages to the parts.

An object of the invention is to provide an improved cam arrangement for the hand flat knitting machine which includes means for camming the mislifted needle, adjacent to the selected needle, to follow a path apart from the needle raiser and needle lowerers, thereby eliminating the collision caused between the needle and the needle raiser and/or the needle lowerers.

Another object of the invention is to provide a cam arrangement for the flat knitting machine which includes a lifting member for lifting the guide bolt of the needle raiser so that the needle raiser is ip its retracted position for the plain knitting. In case of the pattern knitting, the needle can be placed in its protruded position by turning the lifting member.

In one aspect of the invention, the lifting member includes a lower cylindrical body, a rod portion projected-upwardly from the body, a shoulder portion between the body and the rod portion, and a lever weighted with an end mass. The needle raiser can be protruded from and retracted in the base plate through the lifting surfaces, ie, the shoulder portion and the top face of the projecting rod.

The presently preferred embodiment will be described in detail with reference to the drawings, in which: Figure 1 is a perspective view of a part of the carriage of the flat knitting machine in the prior art; Figure 2 is a perspective view of a part of the carriage which features two anticollision cam at the lower portion of the base plte; Figure 3 is a schematic top view of the hand flat knitting machine; Figure 4 is a sectioned view taken along the line S-S' of Fig. 3; Figure 5 is an enlarged right side view of a portion A of Fig. 3; Figure 6 is a sectioned view of the handles for moving the carriage.

Referring to Fig. 2, there is shown a part of the carriage of a hand flat knitting machine which includes a base plate 20 on which are mounted stitch cams 21 and 22 which are movable in a plane parallel to the base plate, two needle lowerers 23 and 24, two needle raisers 25 and 26, an upper unit 27 and a fixed unit 28. These units cooperatively forming two V-shaped needle paths in the carriage.

Since the above arrangement is known in the arts, the details thereof will not be described hereinafter.

As shown in Fig. 2, the invention features two anticollision cams 29 on the base plate 20, the cams 29 respectively having triangle portions 291 of which one sides 2911 have the inclinations similar to the sides 231 and 241 of the needle lowerers 23 and 24 respectively. The sides 293 of the cam 29 slightly offset from the line on which the sides 232, 242 of the needle lowerers 23 and 24. The edges 2921 and 2922 are on the same line as the edges 233 and 243 of the needle lowerers 23 and 24.

During the knitting operation, if a needle 40 is mislifted together with a adjacent selected needle 41 as shown in Fig. 2, the needle 41 will be directed to the needle path 201 through the camming side 2911 of the member 29 and the side camming 211 of the cam 21, and the needle 40 will be directed through the camming side 292 and 293 of the member 29 so that the needle 40 will not collides the needle lowerer 23. Similarly, if the needle 40 and 41 are at the opposite side of the base plate 20, the other member 29 will prevent the needle 40 from collision with the needle lowerer 24 or needle raiser 26, thereby achieving the protection effect for the needle and the units 23, 24 or 26.

The members 29 not only protect the units 23, 24 and 26 but also can retain the raised needle, after stitching, in a position that enables the needle to perform the next stitching.

This advantage eliminates the requirement of hanging a weighing substance on the knitted fabric.

Referring to Figs. 3, 4 and 5, the carriage further includes a guide plate 40 supported above the base plate 20, as is known in the art. Two guide members 41 and 42 provided on the guide plate 40 for guiding the stitch cams 20 and 21. There are also provided two support members 43 and 44, on the guide plate 40, which is supporting a cam plate 46 and locks 252 and 262 of rectangular shape which are sleeved onto the end portion of guide bolts 251 and 261 which are loaded with springs 264 and extending from the needle raisers 25 and 26. The cam plate 46 is slightly received in the recess defined by two raised portions 442 and 432 of the support members 44 and 43 and is connected, through a connecting rod 481, to a handle 48 by which it can be moved forward and backward in the longitudinal direction of the needle bed.In the knitting operation, the cam surface of the movable cam plate 46 cams the locks 252 and 262 to be lowered or raised for guiding the positions of the needle raisers 24 and 26 for different knitting. Since these parts are known in the art, the details thereof are not described hereinafter.

In the invention, the carriage further features a lifting member 45 for the needle raiser 26. A grip member 263 is provided at the top of the guide bolt 261 which is loaded with a spring 264. The lifting member 45 is positioned in a bore 441 of the support member 44. It includes a lower cylindrical body 451, an upper projecting rod 452, a shoulder portion 450 and a transverse lever 453 with a spherical mass 4531 at its end. The transverse lever 453 is turnable about the axis of the lifting member 45 and resting on the top face of the support 44 so that only cylindrical body of the lifting member 45 is entirely inserted in the bore of the support member 44. If the machine performs the pattern knitting operation, the lever 453 is turned so that it lies in the longitudinal direction of the needle bed 50.At this condition, the lock 262 rests on the shoulder 450 and is camed by the cam plate 46 for pattern knitting.

When it is necessary to perform the plain knitting operation, the operator should lift, prior to the operation, the grip member 263 to raise the needle raiser 26 so that it retracts in the base plate 20. As the lock 262 is lifted, the shoulder 450 is released from the restriction of the lock 263 and the lever turns downward on the inclining needle bed 5 due to the mass 4531, as better shown in Fig. 5.

As a result, the projecting rod 452 is changed in the position, and the top surface of the rod 452 gets into a position below the lock 262.

When the operator releases the grip member 263, the lock 262 rests on the top face of the rod 452 against the bias of the spring 264 as better seem in Fig. 5, thereby making the needle raiser retracted in the base plate 20.

This is an advantage of the invention that is efficient to prevent the needle raiser 26 from being protruded from the base plate 20 undesirably during the plain knitting as is often happened in the usual Operation in which the needle raiser is lifted by the hand of the operator. In addition, this also prevent from damages caused to the needle raiser and the needle. In case of the pattern knitting, the needle raiser 26 can be protruded from the base plate by turning the lever 453 and lowering the lock to rest on the shoulder 450 which is flush with the cam plate 46 which cams the lock 262 to guide the needle raiser 26 as better shown in Fig. 4.

Referring again to Fig. 2, there are shown two guide members 32 for guiding the needle lowerers 23 and 24 respectively. Each guide member 32 is provided with a longitudinal groove 321 in which is provided a fixed screw 31 attached to the reverse side of the base plate 20, and a cam part 332 at the end of the guide member 32 for camming a pin 271 of the respective needle lowerer. The invention further features two stop members 323 which are provided in the guide members 32 respectively. The stop members 323 will limit the movement of the guide members 32 so as to eliminate the impact caused between the face 324 and the fixed screw 31 by bearing itself against the side of the base plate 20 when the guide member 32 is moved toward the intermediate portion of the base plate 20.

This is a further advantage to overcome the drawbacks in that the fixed screws 31 is easily loose and even breaks.

Referring to Figs. 3 and 6, a handle 47 which is used for the reciprocating movement of the carriage on the needle bed 50 is mounted to a mounting block 49 above the needle bed 50 together with handle 48 used for moving the cam plate 46. The handle 48 has a threaded portion 482 threadedly secured to the mounting block 49 and a reinforcement circular member 483 sleeved on to the handle 48. The presenCe of the circular member 483 provides advantages in that the threaded portion 482 will not easily become loose when subjected to the operating force frequently. In addition, when there is a break in the handle 48, the remaining part of the handle 48 left in the block 49, can be easily removed just by turning the circular member 483 for the replacement of the handle.

With the invention thus explained, it is apparent that obvious modifications and variations can be made without departing from the scope of the invention. It is therefore intended that the invention be limited only as indicated in the appended claims.

Claims (5)

1. In a carriage of the flat knitting machine, a cam arrangement including a base plate, an upper needle raiser and a lower needle raiser at the intermediate portion of the base plate, two needle lowerers provided symmetrically with respect to the needle raisers, two stitch cams movable in a plane parallel to the base plate provided symmetrically with respect to the needle raisers, means for guiding the needle raisers, the needle lowerers and the stitch cams, the guiding means including a guide plate supported above the base plate, a cam plate for the pattern knitting movably supported on the guide plate, the cam arrangement being characterized by two anticollision cams for preventing the mislifted needle from colliding with the needle raiser or needle lowerer, the anticollision cams being provided on the base plate lower than the stitch cams respectively and each of which has a camming side for camming the mislifted needle to a lower portion of the base plate apart from the needle raiser and needle lowerer.

2. The cam arrangement as claimed in Claim 2, in which the guide means includes a spring-loaded bolt extending upward from the lower needle raiser and a lock provided at the top portion of the guide bolt and wherein the cam arrangement further comprises a lifting member supported above the guide plate for lifting or lowering the lock so as to place the lower needle raiser in a retracted position in the base plate or a protruded position from the base plate.

3. The cam arrangement as claimed in Claim 2, wherein the lifting member includes a lower cylindrical body, an upwardly projecting neck, a shoulder between the body and the neck, and a lever with a weighted end.

4. The cam arrangement as claimed in Claim 1, in which the guiding means includes means for moving the needle lowerers, the moving means having an elongate member movably attached to the base plate by a screw which is received in an elongate groove and wherein the elongate member includes a means for limiting its movement so that the screw will not be subjected to frequent impact.

5. A cam arrangement of the flat knitting machine as substantially described hereinbefore with reference to the accompanying drawings.