US1940520A - Knitting machine - Google Patents

Description

Dec. 19, 1933. M. zuvuc 7 1,940,520

' KNITTING MACHINE Filed Aug. 2, 1935 I INVENTOR M/cv/HEL Z/M/c '30 set of needles.

Patented Dec. 19, 1933 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to improvements in knitting machines and has particular reference to the needle jacks such as employed in the fiat, link and link type of knitting machine shown in United 5 States Letters Patent #1,669,032, dated May 8, 1928. It will be understood,however, that the present jackis capable of being used on other types of knitting machines, such as the circular machines and those in which the bed plates are inclined relative to each other and commonly referred to as the V-type fiat machines.

Briefly stated, said patent embodies a racking mechanism in which the needles in a stationary needle plate are retracted and the other needle 16 plate subsequently racked or shifted longitudinally of said stationary plate to effect the racking operation. To accomplish this purpose, there is provided a needle opening means including an elongated strip mounted in such relation to the .20 needle jacks of the stationary plate that when said means is operated, the strip will be actuated to engage and retract said jacks and thus act positively to withdraw the associated needles so that they will not contact the needles of the movable plate when the latter is racked. Said needle opening means operates in conjunction with a lock plate which travels lengthwise of each needle plate and is provided with a series of cam locks which control the stitching operation of the associated When a racking operation is to take place, the lock plate and needle opening means operate in sequence so that the latter does not become effective to retract the needles until the lock plate has passed beyond the associated row of needles and reached the end of one of its lengthwise movements. Thereupon said means engages the needle jacks and moves them and the needles connected thereto away from the movable needle plate which is immediately thereafter racked or shifted longitudinally relative to the stationary plate which carries the retracted set of needles. I

In accordance with the present invention, and

in connection with its particular application to the flat type of knitting machines, it is proposed to accomplish the racking operation, with its attendant maintenance of the jacks and their needles in retracted position, without the aid of a needle opening means such as referred to above in which a strip or bar is operated, through the instrumentality of suitable linkage and a cam, to

move the needles away from the needle plate to be racked. -To this end, the opening of the needles is effected by the lock plate at the end of each longitudinal movement thereof and,. in

order to maintain the jacks in the retracted position during the racking operation, a means is provided which will frictionally hold said jacks in such position until the same are again actuated by the lock plate following the comple- 00 tion of said racking operation.

More specifically, the invention contemplates the provision of a spring or its equivalent, carried by each jack and engageable with a wall of the groove in the needle plate in which said jack slides so that sufficient friction will be produced to effectively hold the jack and its needle in a retracted position during the racking or other operations of a knitting machine inwhich said jack and needle must be withdrawn with respect to the 70 opposed needle plate.

The invention idea involved is capable of receiving a variety of mechanical expressions one of which, for purposes of illustration, is shown in the accompanying drawing wherein:

Figure l is a fragmentary plan view of a knitting machine of the fiat, link and link type, illustrating only those portions thereof which are necessary to a complete understanding of the present invention. 7

Figure 2 is a partial transverse section through the needle or bed plates, showing the needles in racked position.

Figure 3 is a bottom plan view of the lock plate which controls the operation of the needles and their jacks.

Figure 4 is an end elevation of said lock plate.

. Figure 5 is an enlarged side elevation of one of the jacks constructed in accordance with the invention.

Figure 6 is an edge elevation thereof.

Referring more specifically to Figures 1 to 4 of the drawing there is partially illustrated there in a knitting machine of the well known fiat, link and link type a portion of the framework of which is indicated by the numeral 10 and which includes longitudinal carriage rails one of which is designated at 11. The frame 10 supports the forward and rear needle plates 12 and 13, re-

spectively, the former of which in this particular type of machine, is stationary while the plate 13 is movable longitudinally to accomplish the racking operation. For this latter purpose, the plate 13 carries a rackingbar 14 projecting from one end of the plate and reciprocating by a cam 15 engageable with rollers 16 on said bar. Reference is made to the above identified Letters Patent for a more detailed explanation of the operation of the racking mechanism. It is suflicient to note here that said operation takes place at either end of the longitudinal movement of the carriage 17 which slides on the rails 11 and which carries a lock plate 18 for each of the sets of needles in the plates 12 and 13. The plate 18 has, on its under side, a series of cams or looks 19 arranged, in accordance with the design of the fabric to be knitted, soas to provide a guide channel 20 for receiving the projecting portions 21 of the needle jacks 22 each mounted in a groove 23 in one of the needle plates. Thus, as the carriage is reciprocated, the lock plate passes over its associated row of jacks and needles, with the projections 21 of said jacks successively entering the channel 20 to be moved back and forth thereby so as to similarly operate the associated needles 24. It is to be notedthat the ends of the channel 20 are so disposed that irrespective of the direction of travel of the plate 18, each jack, as it leaves either end of the channel, will be retracted or withdrawn away from the opposed needle plate. In other words, each passage of the lock plate over the needles, leaves them in a position in which the racking operation of the plate 13 may be accomplished and, in this manner, the use of a separate needle opening mechanism such as shown in the aforementioned patent is made unnecessary.

With the jacks thus retracted, the racking operation proceeds and during the interval thereof and until the lock plate is moved in the other longitudinal direction to again operate the needles, said jacks are, in accordance with the present invention, frictionally maintained in their retracted position. This is accomplished, as shown in Figures 5 and 6, by providing one side of each jack, intermediate its ends, with a longitudinal recess 25 for receiving the end portions of a leaf spring 26 of less width than that of the jack and the medial portion of which is bowed so as to extend outwardly beyond the surface of said side, one end of said spring being suitably secured in said recess as indicated at 27. The outwardly bowed portion of said spring will thus engage the adjacent wall of the groove 23.

in which it slides and, due to the resiliency of the spring, sufficient friction will be produced between the same and said wall to retain the jack in the retracted position to which it has been adjusted by the lock plate; but the pressure of the. spring against said wall will not interfere with the free sliding movement of the jack when it is being actuated by said plate.

Instances arise, in the assembly of the locks 19, when those opposed to each other are spaced a greater distance apart than that shown in Figure 3, that is, portions of the channel 20 are greater in width than the projections or butts 21 of the jacks. With the ordinary type of jacks, when the lock plate passes thereover and the butts register with said wider portions of the channel, there is considerable lengthwise play of the jacks. As a consequence, said butts strike against a wall of the channel with considerable force, causing much noise in the operation of the machine. This noise is eliminated with the present form of jack owing to the frictional engagement of the spring 26 which acts to prevent longitudinal shifting of the jack when the wider portions of the channel 20 are passing thereover.

Aside from the foregoing advantage that the present spring affords during a racking operation of the needle plates, it also operates effectively to frictionally maintain the butt of its jack in longitudinal alignment with the other jack butts after the lock mechanism has passed thereover, as shown in dotted lines in Figure 3, and thus prevents any shifting of the jack, due to vibrations of the machine or other causes, which might otherwise result in the breaking of the jack or of the associated needle when the machine carriage and the lock mechanism make their return movement over the needle plate. Furthermore, this maintenance of the jacks in longitudinal alignment results in the production of more uniform stitches.

It is further to be noted in connection with the jacks commonly used, that is, ones without springs, that their butts ride loosely in the groove of the lock mechanism, and as a consequence, they strike the opposite sides of the looks with such force, at times, that the needles become disengaged from the jack hooks and are thereby damaged. The present jack, with its spring, overcomes this defect and reduces to a minimum any damage which might otherwise result from this source.

There are times, such as when some particular design is to be made in the fabric to be knitted, that certain of the jacks and their needles on the front needle plate of the machine are pulled out of operation by being withdrawn away from the back needle plate so that the lock mechanism will not operate upon said jacks. In such instances, the inoperative jacks are again frictionally held, by their springs,'so that vibration of the machine will not have a tendency to inadvertently throw the jacks into the path of the lock mechanism and damage to said jacks will, therefore, be avoided.

In the usual type of knitting machine, a steel plate is provided on the needle plate against which the jacks strike and from which they rebound when operated upon by the jacquard lock. The present spring on the jack, by reason of its frictional engagement with the wall of the groove in the needle plate, decreases this rebounding action of the jack to an extent which permits of the speed of the machine being materially increased.

Some of the above advantages are obtained when the present jack is used on circular knitting machines and, in addition, the spring prevents dropping of the jack when it is moving upwardly in its vertical groove on such circular machines. Also, when used on the so-called V-type fiat machines, the bottom springs on such machines can be eliminated, as the spring on the present jack creates suflicient friction to adequately hold the same.

Lastly, it is well-known that in flat machines, the bed or needle plates are made of a relatively soft metal, such as steel which has not been tempered or hardened. Therefore,'any attempt to produce friction between the jack and a wall of its groove in the needle plate by a spring, or its equivalent, which is of the same, or substantially the same, width as the jack itself, will produce a wear upon said wall which will, in time, widen said groove to such an extent that the jack will be loose therein and thus have its efficiency of operation reduced. On the other hand, by making the spring 26 of less width than the jack, any wear upon the wall of the groove engaged by said spring will be along an intermediate longitudinal area of said wall, that is between the upper and lower edges thereof, and as a consequence, the effective width of the groove in which the jack is moving will remain the same at all times. Furthermore, the spring is very light in weight and consequently the amount of wear upon the wall will be reduced to a minimum.

What is claimed is: l

1. A jack for use in a knitting machine, said jack comprising a body movable in a groove in a needle plate of the machine, one surface of said body having a shallow elongated recess intermediate the side and end edges of said body, one end of said recess being provided with inwardly extending portions to form holding means for a. leaf spring, and a resilient leafspring one end of which extends beneath said inwardly extending portions to be secured in the recess thereby, said leaf spring engaging a wall of said groove with sufiicient pressure to maintain said jack frictionally in various positions of adjustment thereof.

2. A jack for use in a fiat link and link knitting machine ,in which one needle plate is racked relatively to another, said jack comprising a. body movable in a groove in one of said plates, one surface of said body having a shallow elongated recess intermediate theside and end edges of said body, one end of said recess being provided with inwardly extending portions struck from said body to form holding means for a leaf spring, and a resilient centrally arched leaf spring one end of which extends beneath said inwardly extending portions to be secured in the recess thereby, said leaf spring engaging a wall of said groove with sufficient pressure to maintain said jack in a retracted position during racking of said plates,

, said leaf spring being of a width slightly less than

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