US2180241A - Bkake means for yarns - Google Patents

Description

wf; A. ,ING-ALLS BRAKE MEANS FOR YARNS Nov. 14, 1939.

/Filed Feb. 4, 11938 ml. .W8/8%,

Patented Nov. 1,4, 1939 UNETED STATES BRAKE MEANS Foav YARNs Willis A. Ingalls, Syracuse, N. Y., assigner'l to Tompkins Bros. Co., Syracuse, N. Y., a corporation of New York Application February 4, 1938, Serial No. 188,763

Claims.

This invention appertains to improvements in yarn changing or striping attachments for knitting machines, and more especially, to braking K l means for eectively stopping the movement of 51 the yarn when the yarn is taken out of the knitting action.

Yarn changing instrumentalities, as applied to circular spring needle knittingmachines and the like, generally include two or more movable guide lingers through which the yarns to be knittted are threaded, the movement of the lingers being preferably pattern-controlled so as to selectively move the yarns into and out of operative relation to a stitch wheel which serves to feed the yarns into the needles of the rotary needle cylinder. have found that in certain types of yarns, more especially in the case of natural or artificial silk yarns, including acetate yarns, the yarn has a tendency to continue to run through the eyes and guides after its guide finger has moved away from the stitch wheel to take the yarn out of the knitting action, this continued movement being primarily due to the inertia or momentum of the yarn. As a result of this continued movement of the yarn after it has been moved away from the stitch Wheel, and even though the over-run is only momentary, so much slack is produced in the yarn between the guide fingers and the cutter and clamp init frequently happens that the yarn will miss the stitch wheel when the guide finger is returned to its position in which the stitch wheel is adapted to engage the yarn to feed it into the needles, or

insure a more positive action of the yarn changing instrumentalities in respect to the presenting of the yarns to the stitch wheel or other device, as the case may be, which feeds the yarn to the needles of the knitting machine. To this end, I provide a brake device which preferably effects a clamping action upon the yarn when the yarn is taken out of knitting action,the`brake being restrumentalities usually associated therewith, that leased Vwhen the yarn is restored to knitting action.

Another object of the invention is to provide a yarn brake or clamp which ispreferably operable responsive tothe operation of the guide linger o-f 5 a conventional yarn changing attachment, the operation of the brake or clamp being such that the same is rendered effective to immediately stop the movement of the yarn when the guide finger is shifted to its idle or non-feeding position, but being rendered ineffective so as to release the yarn and permit it to move under normal lrunning conditions incident to ,movement of the guide finger to an operative yarn feeding condition.

Other-and further objects and advantages of the invention will be hereinafter described, and the novel features thereof defined by the appended claims. l

In the drawing Figure 1 is arview in side elevation of a yarn changing attachment for a circular spring needle knitting machine, the pattern-controlled cams which actuate the yarn guide fingers being shown in broken lines, and the -yarn changing attachment having my invention incorporated therein;A and r Figure 2 is a top plan View of the yarn changing attachment shown in Figure 1.

Like reference characters designate corresponding parts in the figures of the drawing, wherein I generally designates one form of yarn changingor striper attachment which is available on the market at the present time, and which is primarily intended for use with circular spring needle knitting machines. The details of the knitting machine are immaterial tothe present invention,-and have therefore not `been' shown in the drawing.. Also, it isto be understood that my invention 'is :not limited to use with the particular type of yarn changing attachment shown in the drawing, since the details may be varied or modified as desired and without affecting the basic idea underlying the invention. Accordingly, the construction of the yarn changing instrumentalit-ies as shown in the drawing and hereinafter described should be taken as an illustrative example only, and not in any sense as a limitation of the scope of the invention.

' As in conventional yarn changing mechanisms, there are usually provided two or more guide fingers 2, 2", which are pivotally mounted, as at 3, between spaced standards 4, 4 which form a part of the frame il of the attachment. The pivotal axis 3 of the 'guide ngers is preferably inclinedv so that the lingersA move in inclined planes towards and away from the stitch wheel (not shown) which is usually mounted outside of the circle of needles carried by the rotary needle cylinder of the knitting machine, as will be understood by those familiar with the art. According to the construction illustrated in the drawing, the guide finger 2 is in its uppermost position which constitutes the yarn feeding position by reason of the fact that when so positioned, the yarn 6 which is threaded through the eye I at the free end of the finger 2, is carried upwardly towards the stitch wheel so as to be engaged by the latter and consequently fed into the needles. The other guide finger 2' is shown in its depressed condition corresponding to the non-feeding position of the yarn 8 which is threaded through the eye 9 at the free extremity of this finger. When the finger 2 is actuated to its depressed position just referred to, the yarn 8 which is guided by this finger is moved away fromY the stitch wheel, so that the stitch wheel cannot engage the same and therefore cannot feed Athis yarn into the needles. As the finger 2 reaches its non-feeding depressed condition, the yarn 8 is severed and clamped at a point between the stitch wheel and the needles by means of cutting and clamping instrumentalities, generally designated I0. The stitch wheel is normally positioned intermediate the cutter and clamping device I0 and the guide fingers 2, 2', with its axis disposed somewhat above the uppermost position of the guide fingers so that the yarns are presented by the guide fingers to the lower edge of the stitch wheel when the guide fingers are actuated to yarn feeding position. Thus, when the yarn, such as yarn 8, is taken out of the feeding action, and the yarnis severed and clamped by the device I8, the portion of this yarn which extends between the finger 2 and the device |Ii lies below and in spaced relation to the stitch wheel, and remains in such position until the nger 2 is actuated to a yarn feeding position corresponding to the position in which the guide nger 2 is shown in the drawing. As the finger 2 reaches` the yarn feeding position, the cutter and clamp device I8 is actuated to release the end of the yarn so that the yarn can be freely drawn through the eye 9 by the feeding action of the stitch wheel, thus corresponding to the condition represented by the yarn 6, which, as shown in the drawing, is disposed in a feeding or running position.

The guide fingers 2, 2 are preferably alternately actuated so that when one finger is depressed to take its yarn out of the knitting action, the other finger is raised to put its yarn into the knitting action, and vice versa. 'I'he guide fingers are preferably pattern-controlled by suitable automatically operating instrumentalities, and since the details of these instrumentalities arenot material to the present invention, only a brief general description thereof will be given. i

The frame 5 of the yarn changing or striper unit is preferably mounted on an upright stand I I, which is disposed in outwardly spaced relation to the needle circle, the frame being preferably adjustably secured to the stand by a suitable fastening, such as the bolt I2, which extends through the slot I3 in the stand and into the frame 5. When the device is so mounted, the guide fingers 2, 2 are disposedsubstantially radially respecting the circle of needles carried by the needle cylinder of the knitting machine. Pivotally mounted at I4 between a pair of lugs or bosses I5, I5, are a pair of bell-cranks I6, I6'.

One arm I'I of the crank I6 is operatively connected by a link I8 to the guide finger 2, and the corresponding arm I'I' of the crank I6 is operatively connected to the guide finger 2' by a link I8. Mounted in the frame 5 and freely shiftable axially therein are a pair of push pins I9, I9', the upper extremities of which bear against the lower sides of the respective arms 20 and 28 of the bell cranks I8, |65', and the lower ends of these push pins coact with a notched cam wheel 2| which is rotatably mounted in the frame 5. The notches 22 are so arranged in the upper end of the cam wheel 2| that when one push pin registers with a notch so that its lower end will be received therein, the other push pin will en- -gage the upper end of the cam wheel 2| between two adjacent notches. Tension springs 23, 23' serve to normally rock the respective bell-cranks I6, I6 in a counter-clockwise direction as viewed in Figure 1. Spring 23 has one end. secured to a convenient point on the frame 5, as at 24, and its other end secured to a post or pin 25 which projects laterally from the crank arm |I near the free extremity thereof. Similarly, spring 23 has one end suitably fixed to the frame 5, as at 24, and its other end secured to a post 25 laterally projecting from the crank arm I'I near the free extremity of the latter.

By intermittently rotating the cam wheel 2|, the push pins I9, I9 will be alternately raised and lowered, thereby alternately rocking the bellcranks I8, I 6 in opposite directions, which in turn causes the guide fingers 2, 2 to be alternately elevated and depressed. As shown in the drawing, the intermittent motion is imparted to the cam wheel 5 by means of a ratchet wheel 28 which is fixed to the vertical shaft 2l, which is rotatably mounted in the frame 5 and to the upper end of which the cam wheel 2| is Xedly secured. A spring pawl (not shown), carried by an arm 28 which is rotatably mounted on the shaft 2I for movement in a horizontal plane, coacts with the ratchet wheel 26 to intermittently rotate the ratchet wheel responsive to swinging movement of the arm 28 in one direction, the arm 28 being normally urged in the opposite direction by a spring 29 having one end connected with the arm and the other end connected to a convenient part of the frame 5, as at 38. Swinging movement is imparted to the arm 28 preferably by means of a pattern controlled cam 3| which is mounted on the rotary needle cylinder of the knitting machine. This cam, according to one well known construction which is in use at the present time, is movable from an operative to an inoperative position and vice versa, respecting the arm 28. When the cam 3| is in its operative position, as shown, it strikes an adjustable extension 28' carried by the free end of the arm 28, thereby imparting a swinging movement to the arm 28 and actuating the ratchet wheel 25 one step. After the cam 3| has swung the arm 28 and actuated the ratchet wheel one step, as just described, continued rotation of the needle cylinder on which the cam is mounted disengages the cam from the extension 28', thereby allowing the arm 28 to return to its normal position under the inuence of the spring 29, and conditioning the mechanism for succeeding step-by-step operations as the cam 3| is carried around with the 'needle cylinder, and until the cam is shifted to an inoperative position.

The cutter and clamping instrumentalities I8 are preferably similarly' operated in timed relationto the guide ingers'Z, 2, by meansA of a second cam 32, also mounted on the rotary needle cylinder, and also preferably movable from operative to inoperative position along with the cam `3 l This cam 32 coacts with an adjustable arm 33 carried by a member 34 which is xedly mounted on a lever arm 35, the lever armbeing pivotally connected intermediate its ends to the frame 5, as at 36. One end of the lever arm 35 is connected, as at 37,-to one end of a tension spring 38, the opposite end of the spring 3B being connected to a convenient point on the frame 5, as at 39. Adjustably mounted at the opposite end of the lever arm 35, is an upstanding post 43, and a link 4l interconnects the upper end of the post 4% with the movable parts of the cutter and clamp instrumentalities iii, these instrumentalities being suitably supported on the frame 5 by a bracket arm ill. The spring 38 normally serves to actuate the device i to its yarn cutting and clamping position, as illustrated in Figure 1, whereas engagement of the cam 32 with the part 33 during rotation of the needle cylinder ac-tuates the pivotal lever 35 and the parts interconnected therewith so as to open the cutter and clamping device to release one yarn as it is put into knitting action, and to receive the other yarn as it is taken out of the knitting action. The same cutter and clamping instrumentalities HJ serve to alternately coact with both yarns and 8, and the actuation of these instrumentalities continues intermittently as the needle cylinder rotates and responsive to the cam 32 until this cam is moved to inoperative position.

So much of the construction of the yarn changing mechanism and the operation thereof, as above described, is well known, and I will now explain my invention as applied to this mechanism. As shown in the drawing, the yarns 6 and 8 run from a suitable source, generally designated Y, to the yarn changing attachment, and are threaded through eyes 42, 43, respectively, provided in the frame 5 at opposite sides thereof. Each eye is preferably provided with a porcelain bushing 44, so that the yarn will run freely through the eye without engaging any sharp edges which would tend to damage or sever the yarn. From the eyes 42, 43, the yarns extend to the eyes 'i and 9, respectively, of the guide fingers 2, 2'. With some types of yarns and in some types of knitted patterns, it is desirable to apply a tension to the yarn during the feeding or running of the yarn, and to this end, a plurality of horizontally disposed wires 45 are provided in the frame 5, these wires lying substantially transversely to the direction of the feed of the yarn. By running the yarns under and over the wires 45, a light drag or tension is produced on the yarn. This is a running tension and should not be confused with the braking action on the yarn, to which the present invention primarily relates. By varying the threading arrangement of the yarn respecting the wires 45, the running tension on the yarns can be varied, and in some cases, it is not necessary to run the yarn through the wires 45 at all. However, where silk yarns and the like are being used, and even though the yarn is threaded through the tension wires 45, the inertia or momentum of the yarn is often times so great as to cause the yarn to continue to run after the yarn has been taken out of the knitting action through depressing its guide ringer to disengage the yarn from the stitch wheel. This momentum results in the production of considerable slack in the yarn, and this slack may be so great in the portion of the yarn extending between the guide finger andthe cutting and clamping device .as to prevent the yarn from being reengaged with the stitch wheel to restore the same into the feeding action; or the stitch wheel may momentarily miss the yarn and thus allow the point in the needle circle at which it is desired to introduce the yarn to pass by the stitch wheel before the yarn is picked up by the stitch wheel and fed to the needles. In some striped patterns, this would result in a flaw in the pattern.

To overcome the aforementioned difficulty, I preferably provide one or more braking instrumentalities for the yarns, depending upon the type of yarns being used. As shown in the drawing, the braking device preferably comprises a hat spring blade 46, which is disposed over the eye through which the yarn passes through the frame 5, the blade being generally L-shaped and having' its upwardly extending arm 4l secured to a ange 48 .extending laterally from a plate 49 which is pivotally mounted at a convenient point on the frame 5, as at 5U. The plate 4S is offset laterally and oppositely to the flange 4l, soas to provide a part 5l which is adapted to engage the posts or pins 25 or 25 which are carried by the crank arms il and il. The part 5| is preferably slotted, as at 52, so as to allow the plate 49 to rock on its pivot 53 responsive to rocking movement of the guide nger controlling'bell-crank with which it is operatively connected. This brake construction just described is duplicated for each of the yarns 6 and 8 shown in the drawing, but .it is to be understood that this is not essential since the number of brake devices required will depend upon the type of yarns being used. For instance, if one yarn is silk and the other is an ordinary cotton yarn, one brake device for the silk yarn may be all that is required, and theother brake may be omitted. According to the arrangement shown in the drawing, where two brake devices are employed, they are actuated alternately to clamp and release the yarns responsive to the actuation of the guide fingers 2, 2.vv Since the guide fingers are preferably pattern-controlled, the brake devices may be said to be also pattern controlled, having particular reference to the cam 3i which serves to actuate the instrumentalities which intermittently and alternately rock the bell crank IBJS'. When the bell crank I5 is rocked on the pivot I4 in a counter clockwise direction as viewed in Figure 1, the plate 49 is correspondingly rocked in a counter-clockwise direction, thereby moving the free end of the spring blade 45 downwardly against the upper end of the porcelain bushing 44 in the eye 43, and effectively clamping the yarn 8 with a rm but yieldable clamping pressure.

Feeding movement of the yarn is accordinglyv positively discontinued, and the yarn cannot overrun so as to produce slack at any point beyond the eye 43. It will be understood that this braking action on the yarn 8 occurs when the guide finger 2' is depressed to take this yarn out of knitting action. As soon as the finger 2' is elevated to put the yarn 8 back into knitting action, they elevation being effected by rocking movement of the bell-crank i6' in a clockwise direction as viewed in Figure 1, the clamping blade 4S will be automatically elevated to release the yarn 8, and thereby condition the same for its normal runing or feeding movement. 'I'he released condition of the clamping blade 431s shown by the 'clamping blade which is associated with the yarn 6, which, under the conditions illustrated, is being fed to the needles of the knitting machine by reason of the elevated position of the guide finger 2. Thus when the brake is applied'to yarn 8, it is released from yarn 6, and vice versa. Operation of the brake device associated with yarn 6 is the same as just described for yarn 8, the operation being responsive to the pivotal movement of the bell-crank I6.

While the specific details have been herein shown and described, the invention is not confined thereto, as changes and alterations may be made without departing from the spirit thereof, as dened by the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is- 1. In a device of the class described, the combination with a yarn guide operable to and from yarn feeding position, of yarn clamping means interposed between the guide and the source of yarn supply for stopping the feeding movement of the yarn incident to actuation of the guide to one of its positions, said yarn clamping means comprising a flat spring blade mounted for pivotal movement and positively connected with the guide and movable thereby towards and away from yarn clamping position responsive to actuation of the guide.

2. In a device of the class described, a frame, a yarn guide pivotally mounted on said frame and having an eye at its free extremity for receiving a yarn therethrough, means interconnected with said yarn guide for shifting the same about its pivot to and from yarn feeding position, and yarn clamping means interposed between the guide and the source of yarn supply land operable responsive to shifting movement of the guide to one of its positions, said last named means comprising a member pivotally mounted on said frame and having a part extending at one side of the pivot operatively connected with the guide, and said member also having a part extending laterally therefrom at the opposite side of said pivot, and a relatively flat resilient clamping member having one end fixedly secured to the laterally extending part aforesaid and its other end disposed for releasable clamping engagement with the yarn against the frame at a point distant from the eye in the yarn guide. 3. A device as claimed in claim 2, wherein the means for shifting the yarn guide includes a bellcrank lever pivotally mounted on said frame, at a distance from the pivotal member which carries the resilient clamping member, and the pivotal member being connected to one arm of the bellcrank lever by a pin-and-slot connection.

4. An attachment for yarn changing instrumentalities of the class described, including a shiftable yarn guide, comprising a plate adapted to be pivotally mounted on a support, said plate having a laterally off-set extension at one side thereof adapted to be operatively connected With the shiftable yarn guide, and said plate also having a laterally extended flange at its opposite side, and a relatively flat spring blade member of generally L-shape having one of its arms attached to the flange aforesaid, the other of its arms being adapted for releasable clamping engagement with a yarn.

5. In a device of the class described, the combination with a frame, and a pattern controlled yarn guide pivotally mounted on said frame for movement to and from yarn feeding position while a portion of the yarn is disposed contiguous to the frame, of a resilient yarn clamping member also pivotally mounted on said frame for movement towards and away from the yarn, and means for positively connecting said yarn clamping member with the yarn guide aforesaid for operating the yarn clamping member by the pattern control for the yarn guide, whereby to releasably clamp the vyarn between the resilient clamping member and the frame incident to operation of the yarn guide to one of its positions by the pattern control.

WILLIS A. INGALLS.

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