US2114647A - Yarn tensioning means for knitting machines - Google Patents

Description

April 19, 1938. E. J. BERGER 2,114,647

YARN TENSIONING MEANS FOR KNITTING MACHINES Filed July 2, 1957 2 Sheets-Sheet 1 7 FIG Z WITNESSES- INVENTOR:

Emii I Beryez;

ATTORNEYS.

April 19, 1938. E? J BERGER 2,114,647

YARN TENSIONING MEANS FOR KNITTING MACHINES Filed July 2, 1937 2 Sheets-Sheet 2 W1 TNESSES; INVENTOR:

ORNEYS.

6 By Emil JBeTgez;

Patented Apr. 19, 1938 YARN TENSIONING MA Emil J. Berger, Hatfield, Hosiery Mills, Lansda Pennsylvania MEANS FOR KNITTING CHINES Pa, assignor to lDexdale le, Pa., a corporation of Application July 2, 1937, Serial No. 151,617

l Claims.

This inventionrelates to yarn tensions for knitting machines; and it has reference more particularly to yarn tensioning means for flat knitting machines of the Cotton type such as are universally used in the production of full fashioned stockings and the like. In knitting machines of the kind specifically referred to, the tension on the yarns must be increased as the yarn carriers approach the limits of their travel in opposite directions in order to prevent the formation of loose selvage loops along the edges of the stocking blanks. This function is ordinarily performed by what are known as snappers which have the form of flat finger-like elelil merits mounted on rock shafts actuated from the main cam shaft of the machine and which by cooperation with flat spring tongues pinch the yarns and thereby induce an addiitonal drag in them at the proper times. While snappers function satisfactorily in variantly tensioning yarns of the higher counts, their action is too severe on the fine gauge yarns employed in the knitting of the chiffon weight stockings now in vogue, with consequent causation of frequent ruptures of the yarns, and in turn, of press-offs" of the fabrics from the needles of the knitting machines.

The chief aim of my invention is to preclude the above contingencies which objective Irealize in practice as hereinafter more fully disclosed, an through provision of a yarn tensioning means which includes arocker having spaced arms with guide eyes for the yarn, and an associated spring element carrying a wiper, winch, incident to oscillation of the rocker is brought into contact with the span of the yarn extending between the two guide eyes thereby to induce the additional drag at the required times without straining the yarn to the point of breakage.

Another object of my invention is to attain the foregoing advantages with a tensioning device which can be substituted in piace of the regular snap tensions, and which is operable by the standard mechanism provided in the machines for actuating the snappers without necessitating any changes whatever either in the construction or functioning of such mechanism.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein Fig. I is a skeletonized fragmentary cross sectional view of a fiat knitting machine embodying my improved yarn tensioning means.

Figs. 11 and IE are views on a larger scale corresponding to Fig. I and respectively showing the cooperating elements of the yarn tensioning means in different positions; and

Fig. IV is a detail sectional view taken as indicated by the arrows IV-IV in Fig. III.

The machine illustrated in Fig.1 of these draw- 5 lugs for convenience of exemplifying my invention is of well known construction, its needles 5 being mounted in a bar 2, which, incident to the knitting, is actuated in the usual way to move the needles in relation to the sinkers and knock- 10 over bits indicated respectively at 3 and i. As ordinarily, the sinkers 3 are suitably guided for horizontal sliding movement toward and away from the needles I, in a stationary head 5 supported by one of the longitudinal rails 6 of the machine frame. One of the yarns used in the knitting is indicated at "i, the same being drawn from a supply cone 8 within a humidifier box 9 which is mounted on a platform 60 attached to the horizontal base portions of upright brackets 29 at intervals along the machine frame, one of i which brackets is shown at H. Also, as usual, the knitting yarns are fed to the needles by individual carriers aflixed to longitudinal bars 92 which are slidably supported for endwise move- 535 ment in other stationary brackets such as shown at it likewise arranged at intervals along the machine frame, the guide for the yarn i being shown at it. In leaving the cone 8, the yarn. l passes through an eye it in the top of the hu so midifier box a, then over one of a number of studs it on an arm E'l adjustably secured to the bracket in at the rear, then through 2. moistener it at the top of the bracket ll, and then over one of a number of studs 09 on another arm 2t adjustably secured to said bracket at the front. As a result of its travel over the circuitous course defined by these guides, a definite amount of normal tension is maintained on the yarn l as well understood in the art.

The yarn tensioning means with which the present invention is more especially concerned comprises a rocker element El having its hub 22- adjustably clamped by means of a screw 23, to a rock shaft 2 5 which may be one of the usual snapper rock shafts or. the machine, and which, as usual, is journaled in the top of the bracket it. From Figs. 11 and Ill, it will be observed that the rocker 29 is formed with a pair of spaced arms 25 and 25, respectively having eyes 2i, iii through which the yarn l passes. Arranged to cooperate with the rocker 28 is a flexible element in the form of a flat spring tongue which, at one end is secured to the arm it of said rocker by means of a screw tit, and which cv rreaches the arm it.

As shown, the free end of the spring tongue 29 is bent downwardly to engage over a fixed member of the machine, which member may be the rod 3| whereto the guide 'arm 20 is secured, so that said spring tongue is at all times held out of direct contact with the arm 26 of the rocker. Mounted at an intermediate point on the spring tongue 29 is a wiper 32 preferably of closely compressed felted textile fiber. As the rocker 2| moves from the position of Fig. II to that of Fig. III, the wiper 32 is brought into contact with the span of the yarn 1 extending between the eyes 21,28 in the arms 25, 26, and in this way-additional drag is imposed upon the yarn I.

For the purpose of actuating the yarn tensioning devices of my invention, it is possible to utilize the standard snapper actuating mechanism of the knitting machine. As delineated in Fig. I, this mechanism includes an arm 33 on the rock shaft 24 connected by a downwardly extending link rod 34 to one end of a lever 35 which is fulcrumed at 36 on a fixed bracket 31 of the machine frame, and which at its opposite end carries a roller 38 arranged to cooperate with a rotary cam 39 on the main cam shaft 40 of the machine, said roller being held in contact with the periphery of the cam by means of a spring shown at 4|. It is, of course to be understood that the cam 39 is so positioned on the cam shaft 40 as to effect actuation of the yarn tension of my invention to cause additional tension to be imposed on the yarn T as the yarn carrier I 4 approaches the limits of its travel in opposite directions; and moreover that the elements 2| and 29 are intended to be duplicated for the other yarns which may be employed in the knitting.

From the foregoing, it .will be apparent that I in the construction or operation of the usual snapper actuating mechanisms of the machines. Having thus described my invention, I claim:

1. Yarn tensioning means for knitting machines including an element with spaced eyes through which the yarn passes on its way to the needles of the knitting machine; an attached flexible tongue element carrying a wiper; and means for periodically moving the two elements relatively during feeding of the yarn so that the wiper is broughtinto contact with a free span of the yarn between the eyes aforesaid to change the path of the yarn and correspondingly vary its tension.- f

2. Yarn tensioning means for knitting-machines according to claim 1, wherein the wiper is of yielding materiaLlike felt.

3. Yarn tensioning means for knitting machines including a rock shaft; a rocker on said shaft having a pair of arms with eyes-through which the yarn passes enroute to the needles of the knitting machine; a spring tongue secured to one of the arms of the rocker and overreaching the other arm thereof; a wiper medially mounted on. the spring tongue; a fixed element for supporting the free end of the spring tongue and holding it away from the overreached arm of the rocker but permitting said wiper to be periodically brought into contact with a free span of the yarn between the eyes aforesaid as the rocker isoscillated during the knitting thereby to change its path and correspondingly vary its tension.

4. Yarn tensioning means for flat knitting machines in which yarn is directed to a series of needles by a longitudinally reciprocating carrier including a rock shaft; a rocker on said shaft having a pair of spaced arms with eyes through which the yarn passes on its way'to the carrier; a spring tongue secured to'oneof the arms of the rocker and overreaching the other arm thereof; a wiper medially mounted on said tongue; a fixed element for supporting the free end of the springv tongue and normally holding it away from the overreached arm of the rocker but permitting the wiper to be periodically brought into contact with a free span of the yarn between the eyes aforesaid to change the path of the yarn and correspondingly increase its tension; and means for rocking the shaft to bring about the increased tension upon the yarn as the yarn carrier approaches the limits of its travel in opposite directions.

' EMILfl. BERGER.

Images