US3406541A - Yarn feed indexing apparatus - Google Patents

Description

Oct. 22, 1968 L. ROBBINS YARN FEED INDEXING APPARATUS 2 Sheets-Sheet l Fiied May 31, 1966 INVENTOR. Leroy Robbins BY ,6

A T TORNE Y Oct. 22, 1968 L. ROBBINS 3,406,541

V YARN FEED INDEXING APPARATUS Filed May 31, 1966 2 Sheets-Sheet 2 Fig. 3.

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Leroy Robbins WI TNESS BY V Ms lmf CH7 A TTORNE Y United States Patent "ice 3,406,541 YARN FEED INDEXING APPARATUS Leroy Robbins, High Point, N.C., assignor to The Singer glompany, New York, N.Y., a corporation of New ersey Filed May 31, 1966, Ser. No. 553,976 1 Claim. (Cl. 66-138) ABSTRACT OF THE DISCLOSURE A yarn feed controller for knitting machines is disclosed as employing two counter oriented ratchets on a pattern drum. One ratchet is for indexing the controller, and the other ratchet is for preventing override thereof. The controller uses a pair of pawls in cooperation respectively with the ratchets, the pawl to prevent controller override being normally disengaged from its ratchet, but being engageable therewith in response to driving of the controller by the other, or indexing, pawl.

This invention rel-ates ingeneral to yarn feed controllers e.g., as shown in United States Patent No. 2,698,533, for Knitting Machines, and in particular provides an improved form thereof which operates to assure the proper feeding of yarn in high-speed hosiery knitting machines.

Present yarn feed controllers for hosiery knitting machines are generally in the nature of pattern drums having jacks thereon for the proper actuation of respective yarn feed fingers, which drums are respectively provided with cooperating ratchets for indexing purposes. During highspeed knitting of stockings, the feed fingers must move into and out of operation quickly and discretely. This means that the yarn feed controller, too, must be indexed discretely and quickly, for otherwise one or more undesired yarn fingers might be brought into knitting operation at any given time. To assure the proper indexing of a yarn feed controller, prior practice has been to use an exceedingly powerful drive for quickly indexing the controller by means of its ratchet, and to build into such controller a high-friction rotary support, whereby the controller abruptly comes to a halt after being indexed, and does not freely coast to a position whereby an undesired yarn feed finger gets actuated. This practice obviously leaves much to be desired since it not only requires too large a controller drive than should be necessary, but by including a high friction rotary support for the controller, tends to defeat the very purpose for which the whole controller is intended. That is, by building friction into the rotary support of the controller, the tendency is to slow the controller at the very time when its indexing speed of operation is desired to be great.

The present invention overcomes the above noted attendant disadvantages of the prior art by employing two counter oriented ratchets on the pattern drum of the controller, whereby one ratchet is for indexing the controller, and the other ratchet is for preventing override thereof. In this way the above noted built-in friction can be eliminated, whereby the controller indexing drive may be as small as is necessary for the needed speed of operation. In practicing the invention, the presently preferred controller uses a pair of pawls in cooperation respectively with the above mentioned ratchets, the pawl to prevent controller override being normally disengaged from its ratchet, but being engageable therewith in response todriving of the controller by the other, or indexing pawl.

A principal object of the invention is to provide improved yarn feed controller apparatus.

Another object of the invention is to provide yarn feed 3,406,541 Patented Oct. 22, 1968 controller apparatus useful with high-speed hosiery knitting machines.

Another object of the invention is to provide improved yarn feed controller apparatus adapted to be quickly and discretely indexed for the precise feeding of yarns in a hosiery knitting machine.

The invention will be described with reference to thefigures wherein:

FIG. 1 is a side elevational view of a presently preferred form of the invention,

FIG. 2 is a view, partially cutaway, showing details of construction of the apparatus of FIG. 1,

FIG. 3 is a plan view of the apparatus of FIG. 1,

FIG. 4 is a side sectional view, partially cut away, taken from FIG. 3, and

FIG. 5 is a perspective view useful in teaching the concepts of the invention.

Referring to the figures, a hosiery knitting machine has a needle cylinder having the usual complement of needles, jacks, etc., which needle cylinder is supported for rotation about its axis by means not shown. Drivable with theneedle cylinder 10 is a dial assembly 12 having a gear drive 14 that is adapted to be driven by the needle cylinder drive. The dial assembly includes the usual dial 16, in which locates transfer bits for the making of stocking welts, and a dial cap 18 for cam actuating the transfer bits. The dial assembly 12 is arcuately positionable upwardly away from the needle cylinder 10 along an are 20 to gain access to the needle cylinder interior.

Surrounding the needle cylinder 10 is a ring type member 22, against the top face 24 of which respective yarn feed fingers 26 (a, b, 0 etc.) of feed stations A and B respectively are adapted to rest when in yarn feeding engagement. The yarn feed stations A, B are essentially identical and, generally hereafter, though only the feed station A is referred to, the description is relevant also to feed station B. A yarn feed controller 30 cooperates to select which of the respective yarns Y is to be fed to the needles 32 of the needle cylinder 10. The yarn feed fingers 26 are rotatably supported, between a pair of braces 33, on a shaft 34, and are so spring biased by respective springs 36 that the feed fingers 26 are urged toward the ring type member 22. Designed to keep the yarn fingers 26 up and out of yarn feeding engagement with the ring ty-pe member 22 are respective finger control levers 38, which levers are selectively disabled as will be described later to allow the feed fingers 26 to drop selectively into operation.

The finger control levers 38 are rotatably supported on a shaft 40 in a generally U-shaped carriage 42. The shaft 40 extends, at both of its ends, from the carriage 42 and resides in elongated slots 44 in a support post 46. Steadying the carriage 42 for up-down translational positioning are bosses 48, also residing in elongated slots in the support post 46. A comb 52 having slots 54, serves to keep the front ends of the control levers 38 in fixed spaced apart relationship; and a comb 56 similarly operates on the back ends of the levers 38.

A control drum 58 is rotatably supported on a sprag 60 between brackets 62 that are formed as part of the support post 46. The control drum 58 is provided with peripherally located jacks 64 which serve to assert counterclockwise forces (looking at FIG. 1) on the levers 38 by bearing against their respective bosses 66, thereby exerting counterclockwise torques on the respective feed fingers 26 about their supporting shaft 34, and against the tensions of the respective springs 36. Absence of a butt on a jack 64 (when the carriage 42 is in the position shown in FIG. 1) releases a particular lever 38, which in turn releases a feed finger 26 to reside against the face 24 of the ring type member 22 for yarn feeding purposes.

An arm member 68 is rotatably supported on the controller sprag 60, and rotatably supports a pawl 70 that is biased by a spring 72 into engagement with a ratchet 74 fixedly secured to the drum 58. The pawl arm member 68 so supports a bar 76 that upward reciprocation of a pawl drive 78 causes a second pawl 80 to drop from disengagement into engagement with a second ratchet 82, which ratchet 82 is the same as, but counter oriented l with respect to, the ratchet 74, and is also secured to the drum 58. The pawl 80 is rotatably supported by a. bracket 84, and is spring biased by a spring 86 to ride against the bar 76.

A shaft 90, notched sufficiently wide as at 92 to accommodate the control lever carriage 42, is rotatable in the support post 46 by means of a lever 94. With the lever 94 locked in place (see FIG. 1) by means of a carriage lock 96, the carriage rests atop the full diameter of the shaft 90, whereby the levers 38 and their bosses 66 are engaged for actuation by the jacks 64 of the feed control drum 58; with the lever 94 rotated as shown by FIG. 2, the control lever carriage 42 drops into the shaft notch 92, whereby the lever bosses 66 are all disengaged from the drum jacks 64, thus permitting the feed fingers 26 to drop into place against the ring type member 22 of the machine.

As shown by FIG. 2, with the reciprocating drive 78 about set to drive the ratchet 74 and the drum 58 clockwise, the pawl 80 is disengaged from its ratchet 82. At the instant, however, that the drive 78 starts to move upwardly, the bar 76 (which is carried by the pawl support arm 68) starts to drop. This causes the pawl 80, in turn, to drop into engagement with and gradually ride deeper into the teeth of the ratchet 82. At the full clockwise stroke of the pawl 70 against the teeth of the ratchet 74, the pawl 80 locates as shown by FIGS. 1 and 5, thereby preventing any more than one discrete indexing of the drum 58 for each actuation of the pawl drive 78, and effecting a principal object of the invention. On the return stroke of the pawl drive 78, the bar 76 again raises the pawl 80 to its disengaged position, thereby readying the controller for its next indexing.

While the invention has been described in its preferred form, it is to be understood that the words which have 5 been used are words of description rather than of li-mitation and that changes within the purview of the appended claim may be made without departing from the true scope and spirit of the invention.

Having thus set forth the nature of the invention, what is claimed herein is:

1. Apparatus for discretely indexing the yarn feed controller of a knitting machine, said yarn feed controller comprising a bracket, a control drum having a plurality of peripherally located jacks, and a sprag for rotatably supporting said drum within said bracket, said indexing means comprising first and second ratchets secured to said drurn having counter oriented teeth, an arm rotatably supported on said shaft and having secured thereto a first pawl, means for urging said first pawl against said 20 first ratchet, reciprocating means for advancing and retracting said first pawl, a second pawl rotatably supported by said bracket, and means for biasing said second pawl against said second ratchet, means secured to said arm and engageably holding said second pawl away from said second ratchet only when said first pawl is substantially in its retracted position, whereby said drum is assured of a discrete indexing for each reciprocation of said reciprocating means.

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