US2744399A

US2744399A - Yarn feeding mechanism for knitting machines

Info

Publication number: US2744399A
Application number: US514141A
Authority: US
Inventors: West Bertram Henry
Original assignee: G Stibbe and Co Ltd
Current assignee: G Stibbe and Co Ltd
Priority date: 1954-06-18
Filing date: 1955-06-09
Publication date: 1956-05-08
Anticipated expiration: 1973-05-08
Also published as: DE1130107B

Description

May 8, 1956 H. WEST 2,744,399

YARN FEEDING MECHANISM FOR KNITTING MACHINES Filed June 9, 1955 5 Sheets-Sheet 1 /N VENTOR M F BY May 8, 1956 B. H. WEST 2,744,399

YARN FEEDING MECHANISM FOR KNITTING MACHINES Filed June 9, 1955 5 Sheets-Sheet 2 /N VENTOI? EMF/7M HEN/FY W657;

ATTORNEX y 1956 B. H. WEST 2,744,399

YARN FEEDING MECHANISM FOR KNITTING MACHINES Filed June 9, 1955 5 Sheets-Sheet 3 y 8, 1956 B. H. WEST 2,744,399

YARN FEEDING MECHANISM FOR KNITTING MACHINES Filed June 9, 1955 5 Sheets-Sheet 4 VWA WORM-r5 y 8 19 'B. H. WEST 2,744,399

YARN FEEDING MECHANISM FOR KNITTING MACHINES Filed June 9, 1955 5 Sheets-Sheet 5 INVENTOR provided in conjunction United States Patent YARN FEEDING MECHANISM FOR KNITTING MACHINES Bertram Henry West, Rothley, Leicester, England, as-

srgnor to G. Stibbe & Co. Limited, Leicester, England, a British company Application June 9, 1955, Serial No. 514,141

Claims priority, application Great Britain June 18, 1954 8 Claims. (Cl. 66-132) This invention appertains to yarn-feeding mechanism for knitting machines, and concerns such mechanisms of the type comprising means capable of drawing-off yarn from its supply at varying rates on its way to the needles, and adapted to determine these rates in accordance with variations in the yarn tension.

The object of the present invention is to provide, for the purpose hereinafter to be mentioned, an improvement in a yarn feeding mechanism of theform disclosed in the specification of the United States Patent No. 2,537,- 000, that is to say, a mechanism including, in combination, a single tapered roller around the periphery of which yarn can be lapped or wrapped On its way from a supply to the feeder of the machine, the said roller beingadapted to be positively driven so as to exert, frictionally, a drawing-oif action on the yarn, and automatic yarn tension controlling means comprisinga rockable balance compensator furnished'with a pair of depending guides adapted to locate the lap or wrap of the yarn around the tapered roller, and also with anupwardly directed guide for engagement with the run of the yarn betweenthe said lap or wrap guides and thefeeder at which the-yarn is supplied to the needles, the said controlling means being thereby adapted to be influenced byvariations, in tension of the yarn 'du'ring knitting whereby, as the resultof such variations, the position of the lap or wrap of the yarn is shifted by the depending guideslengthwise of the roller so that the diameter of the lap or Wrap is increased or decreased and the rate' 'at which the yarn is drawn from the supply is correspondingly varied as occasion demands.

The tapered yarn measuring roller in the mechanism disclosed in our prior specification is of frusto-conical form and may be made wholly of rubber or like material.

Now when one ofthese yarn-"feeding mechanisms is with each feeder of a multifeeder knitting machine, the tapered rollers of the respective mechanisms are all positively driven at the same speed. As a consequence, a set of'the yarn feeding mechanisms, as heretofore constructed, were only suitable for feeding yarns 'to the needles at the same average speed. Accordinglyj'themechanisms could notbeused in cases where' varying amounts of different yarns were required to be supplied at respectivelydifierent'feeders,

e. g. when producing split feeder work. during. which varying numbers of needles are caused to knit at the different feeders; For instance, in' producing such work all of the needles are sometimes'required to :knitat one or more of the"fe eders, whilst only a proportion of the needles are *knitting'at another-feeder, or otherfeeders, as thecas'e may' ber 'Inthis' regard, a yarn which islto be taken and knitted by all the needles at a feeder must obviously befed-at agreater speednthan a yarn which is to be knitted by'a smaller number of needles at another feeder] The aim of the improvement, .provided by the present invention is to enable yarns to be satisfactorily fed to needles ofamulti-feeder machine at different speeds,

according to requirements.

"ice

According to this invention the tapered yarn measuring roller incorporated in a yarn feeding mechanism of the form described is provided with a parallelsided and smooth surfaced portion adjoining the small end of the said roller.

The improved yarn measuring roller therefore has a frusto-conical inner portion and an adjoining parallelsided outer portion. The surface of the inner portion is formed or otherwise adapted to enhance the frictional grip of a yarn thereon, whereas the contrasting smooth surface of the parallel-sided outer portion is such as to permit of slippage between the latter and a yarn. engaged thereby. i

In addition, provision is made for varying not only the position, forwards or backwards, of the upwardly directed guide relatively to the balance compensator, but also the extent of the permitted rocking movement of the said compensator itself. By virtue of such provision, the extent of the movement of the depending guides lengthwise of the yarn measuring roller can be varied, according to circumstances. For instance, when a yarn is to be positively fed at a varying maximum speed, the guides depending from the compensator must be able to swing to and fro to an extent covering the full length of the frustoconical inner portion of the measuring roller. When, on the other hand, less yarn is required to be fed, the balance compensator is permitted only a restricted degree of rocking movement so that in this case the depending guides cover the parallel-sidedportion and avsmall adjoining part only of the adjoining frusto-conical portion ofthe said roller. 7

The roller can be used in one of three ways hereinafter to be described, and the invention.enables, 'as occasion arises, a plurality of yarns to bev supplied. at different speeds at the feeders of amulti-feeder knitting machine all positively driven at the. same speed.

In order that the invention may be more clearly ,un- I derstood and readily carried into practical effect, aspecific constructional example of the improved yarn feeding mechanism and the alternative ways in which it can be used will now be describedwith reference to the accompanying drawings, wherein,

Figure 1 is a part-sectional side view of the said mechanism showing a yarn, extending from a supply to a feeder of a circular knitting machine lapped around the frusto-conical inner portion of the measuring roller.

Figure 2 is afurther general side view of the mechanism but this time showing a yarn lapped only partially around the parallel-sided outer portion of the yarn measuring roller,

Figures 3 and .4 are perspective views of the yarn feeding mechanism asseen fromthe right and left hand sides or drag on a yarn positioned in the manners'hown in Figure 5, the said yarn is drawn from the parallel-sided outer portion of the measuring roller onto the'frustoconical inner portion thereof, for the purpose hereinafter to be described.

Figures 7 and 8 are two further perspective ,views as seen from opposite sides of the mechanism showing a yarn lapped oneand a half times around the parallelsided outer portion of the measuring roller and,

Figure 9 is a side view of the improved measuring roller per se.

Like parts are designated by similar reference characters throughout the drawings.

Referring to Figure 1, the reference numeral 1 indicates a carrier disc for a cone or other wound package such as 2 of yarn Y. This disc is carried by a radial arm 3 secured at its inner end in a bracket 4 mounted upon a ring 5 associated with a spider 6 or the like carrying the central vertical column of a superstructure (not shown) such as is commonly mounted on the top of a circular knitting machine of the cylinder and dial type. A few of the cylinder needles of the machine are shown at 7, and co-operating dial needles at 8. 9 represents a yarn feeder bracket furnished with an eye 10 through which yarn Y drawn from the package 2 is fed to the needles at a knitting location. From the package 2, the yarn Y extends first upwards through a knot catcher 1i and then after passing over the appropriate element of a stop motion device 12 passes through a pot eye 13 and downwards to the yarn feeding mechanism designated generally by the letter A.

This mechanism is as described in our prior specification No. 2,537,000 aforesaid and comprises a single, mainly tapered yarn measuring roller 14 secured onto a spindle 15. The said spindle is journalled, as shown in Figure 1, in a hushed bearing 16 provided in the wall of a fixed circular casing 17 which is centrally bossed at 18 to receive the lower end of the vertical column of the aforementioned superstructure. The inner end of the spindle is provided with a pinion 19 arranged in mesh with a crown wheel 20 adapted to be driven from a shaft (not shown) in turn driven from the main driving gear of the machine. Thus, the measuring roller 14, which is arranged horizontally above the needles, is positively driven in a continuous manner.

Associated with the measuring roller 14 are automatic yarn tension controlling means constituted by a balance compensator 21. This compensator is mounted to rock about a stub axle 22 (see Figures 3, 5 and 7) fitted on a bracket 23 carried by the casing 17 and may, if desired, be provided with an adjustable counterweight 24 for adjusting the rocking compensator 21 to suit different grades of yarn. As will be seen more clearly in Figures 3, 5 and 7, the bracket 23 is provided with an upwardly directed extension 2311 the upper end 23b of which is bent into a horizontal plane and drilled to receive a fixed pot eye 25 through which the yarn Y extends vertically downwards to the yarn feeding mechanism A.

Depending radially from the balance compensator 21, normally to a location between the ends of the measuring roller 14, are two closely

adjacent yarn guides

26 and 27. In order to produce rocking movements of the compensator 21 for the purpose hereinafter to be described, the said compensator is furnished with an additional guide 28 which extends upwardly and is located between the compensator and the yarn feeder bracket 9. The guide 28 consists of a length of wire provided at its outer end with a pot eye 29. Between the

guides

26 and 27, is a still further guide in the form of a feeler or dropper 30 having associated therewith a contact 31 (Figure 1) arranged in an electrical circuit including an electrical stop motion whereby, in the event of abnormalities such as yarn failure or breakage, the feeler or dropper 30 is released and closes a circuit to initiate stoppage of the machine. The contact 31 is co-operable with a spring contact 32.

In accordance with the characteristic feature of the present invention, the improved tapered yarn measuring roller 14 comprises, as shown more clearly in Figure 9, an inner frusto-conical portion 14a which is made of rubber (e. g. polysar rubber) and has a knurled or equivalent surface, and an outer parallel-sided portion 14b made of hard polished ebonite. The ebonite portion 141: may conveniently be located in the mould employed to produce the moulded rubber portion 14a so that the two portions become integrated into n. single article in turn moulded or vulcanised onto the spindle 15 which is of metal. The inner portion 141! of the roller may alternatively be made of a material having the nature of rubber.

Being located beneath the measuring roller 14, the aforementioned feeler or dropper 30 is unsuitable for use when a yarn is threaded up in such a way as to extend around the parallel-sided outer portion of the roller. For this reason, an additional device such as 33 (Figures l and 2), equivalent to the feeler or dropper 3t) and adapted to perform the same function is provided in conjunction with each yarn feeding mechanism A and at a more suitable location. For example, and as shown, the additional device 33 may conveniently be disposed in front of and in line or approximately so with the pot eye 29 of the wire guide 28 on the compensator 21. It is to be clearly understood, however, that both the feeler or dropper 30 and the additional device 33 can be used when a yarn is lapped around the frusto-conical Portion 14a of the measuring roller.

Now, as previously mentioned, when a yarn is to be positively fed at a varying maximum speed, the

guides

26 and 27 must be able to swing to and fro to an extent covering the full length of the frusto-conical portion 14a of the measuring roller whereas, when less yarn is required, the balance compensator 21 is permitted only a restricted degree of rocking movement. To this end, the wire guide 28 is adjustable upon the compensator, and the extent of the permitted forward rocking movement of the latter is variable by appropriate adjustment of a stop such as 34 depicted in Figures 3, 5 and 7.

The inner end of the wire guide 28 is formed into an eye which is mounted upon a screw 35 the head of which is depicted in Figures 3, 5 and 7. This screw extends through a hole formed in the appropriate wall of the compensator 21 and is furnished with a nut (not shown) accommodated within the hollow interior of the said compensator. Thus, by slackening the screw 35, the wire guide 28 can be turned forwards or backwards relatively to the compensator and thereupon be secured in its adjusted position by re-tightening the screw. There are two positions of the wire guide 28, viz. a forward positiondetermined by a nick (indentation) 36 cut in the periphery of the back plate of the compensator 21, and a back position determined by a second nick 37 spaced a short distance rearwardly from the first.

Projecting laterally from the back plate of the balance compensator 21 is an abutment pin 38 so arranged as to come into contact with the relatively fixed stop 34, at appropriate times, for the purpose of limiting the forward rocking movement of the compensator and hence the rearward swing of the two depending

guides

26 and 27 towards the end of the roller 14 of largest diameter. The stop 34 is constituted by one limb of a smaller angular element the other limb of which is attached, by a screw 33, to the extension 2311 of the bracket 23. By adjusting the stop 34 in an upward direction, as shown in Figure 3, the compensator 21 is permitted its maximum forward rocking movement, whereas with the said stop in its down position (Figures 5 and 7) the permitted movement of the compensator is restricted.

It is important to realise that the gear drive to the various measuring rollers 14 of a plurality of yarn feeding mechanisms A fitted to a single circular knitting machine is that which will best suit the fastest yarn delivery.

Of such a plurality of yarn feeding mechanisms A those required to feed most yarn to the relevant feeders are each set and threaded up in the manner illustrated in Figures 1, 3 and 4. That is to say, the wire guide 28 is disposed forward in the nick 36, the stop 34 is set in its up position, and the yarn Y (extending down through the fixed pot eye 25) passes first through the depending guide 26, then once around the frusto-conical inner portion 14a of the yarn measuring roller 14, through the companion depending guidev 27, down and through the pot eye 30a of the feeler or dropper 30, upwards again and through the pot eye29 of the wire guide 28 of the balance compensator, then, outwards to the additional stop motion device, downwards through the aligned pot eyes of this device and finally through the eye of the feeder bracket 9. In these circumstances, the yarn Y willbe more or less positively fed at a maximum speed, the varying rates at which the yarn is drawn from the supply 2. being determined by the positions towhich the lap or wrap Y of the yarn is shifted lengthwise, of the frusto-conical portion,14a of the roller 14 by means of the rocking compensator 21-,-all as described in our prior specification.

, On a feed requiring less yarn, it is necessary to use the .slipfhaction of the measuring roller 14,, by arranging for the yarn Y to be lapped or wrapped around, and to run on, the parallel-sided ebonite portion 14b, in the mannershowndn Figures 7 andS As will be seen, the wire guide 28 is in this case set back into the nick 37 and the stop 34 is moved into its down position so asto restrict the rocking movement of the compensator 21'. When feeding less yarn, moreover, the yarnfeeler or dropper 30 is not used. The yarn Y extends down through the depending guide 26, one and a .half times around the parallel-sided ebonite portion 14b of the roller, through the depending guide 27, from thence straight up and through the pot eye 29, out to the stop motion device 33 and finally down to the feeder. In this case it may be found desirable to exercise additional control over the yarn Y, e. g. by using a yarn tension button within the appropriate pot eye on the device 33.

In a case where extra slow feeding is required, the yarn Y may, as depicted in Figure 5, be passed through only the first (26) of the two depending compensator guides so that it will extend only half way around the parallel-sided ebonite portion 14b of. the tapered yarn measuring roller 14. Here again, the dropper 30 is not used. In the event of a snatch or drag on the yarn Y, resulting either from the poor quality of the yarn or bad winding at the supply, the yarn tension compensator 21 will be caused to rock and, in so doing, will draw the yarn from the smooth surfaced parallel-sided outer portion 14b of the roller 14 onto the frusto-conical inner portion 14a thereof (see Figure 6). As a consequence,

the speed of the yarn will be temporarily increased to compensate for the snatch or drag. In other words, fluctuations in the tension of the yarn will be absorbed or evened out by the compensator.

Accordingly, in the cases illustrated both in Figures 5 and 6 and in Figures 7 and 8 the roller 14 will be driven at a speed in excess of that required but, by virtue of the fact that the parallel-sided outer portion 14b of the said roller has a smooth surface, there will be relative slippage between the roller and the yarn.

I claim:

1. For a knitting machine equipped with a plurality of feeders, a yarn feeding mechanism comprising, in combination, a single positively driveable yarn measuring roller consisting of a frusto-conical inner portion having a surface adapted to enhance the frictional grip of a yarn wrapped therearound and a parallel-sided outer portion adjoining the small end of the said inner portion, said parallel-sided portion having a smooth surface to permit of slippage between the latter and the yarn in the event of it being engaged thereby for the purpose specified, and automatic yarn tension controlling means in the form of a rocking compensator furnished with depending guide means adapted to locate a lap of the yarn around the measuring roller and also with an upwardly directed guide to engage'the run of the said yarn betwee nthe said depending guide means and a feeder of a knitting machine, the said controlling means being thereby influenced by variations in tension of the yarn during knitting.

2. A yarn feeding mechanism according to claim 1, wherein the frusto-conical inner portion of the yarn measuring roller is made of rubber and has a knurled surface, whereas the outer parallel-sided portion is made of hard polished ebonite, the two portions being integrated into a single componentwhich is moulded onto a metal spindle. v y p j 3. For a knitting machine equipped with a plurality of feeders, a yarn feeding mechanism comprising, in combination, a single positively driveable yarn measuring roller consisting of a frusto-conical inner portion having a surface adapted to enhance the frictional grip of a yarn wrapped therearound and a parallel-sided outer portion adjoining the small end of the said inner portion, said parallel-sided portion having a smooth surfaceto permit of slippage between the latter and the yarn in the event of it being engaged thereby for the purpose specified, automatic yarn tension controlling means in the form of a rocking compensator furnished with depending guide means adapted to locate a lap of the yarn around the measuring roller and also'with an upwardly directed guide to engage the run of the said yarn between the said depending guide means and thefceder of a knitting machine, the said controlling means being thereby influenced by variations in tension of the yarn during knitting, means enabling the position of the said upwardly directed guide relatively to the compensator to be varied, and presettable means enabling the degree of the permitted rocking move ment of the said compensator to be varied whereby the extent of the movements of the depending guide means to and fro lengthwise of the yarn measuring roller can be changed according to circumstances.

4. A yarn feeding mechanism according to claim 3, wherein the upwardly directed guide is mounted upon a screw whereby it can be set in an adjusted position upon the compensator, and the latter is formed with spaced indentations for receiving and determining alternative positions of the said guide.

5. A yarn feeding mechanism according to claim 3, wherein the compensator is provided with an abutment adapted for co-operation with an adjustable stop carried by a fixed bracket upon which the compensator is mounted to rock.

6. A multi-feeder knitting machine which includes, in combination, .a plurality of yarn feeding mechanisms,

one to each feeder, each of said mechanisms comprising a single yarn measuring roller consisting of a frusto-conical inner portion having a surface adapted to enhance the frictional grip of a yarn wrapped therearound and a parallel-sided outer portion adjoining the small end of the said inner portion, said parallel-sided portion having a smooth surface to permit of slippage between the latter and the yarn in the event of it being engaged thereby for the purpose specified, and automatic yarn tension controlling means in the form of a rocking compensator furnished with depending guide means adapted to locate a lap of the yarn around the measuring roller and also with an upwardly directed guide to engage the run of the said yarn between the said depending guide means and the relevant feeder, the said controlling means being thereby infiuenced by variations in tension of the yarn during knitting, and means positively driving all of the yarn measuring rollers at the same speed.

7. A multi-feeder knitting machine which includes, in combination, a plurality of yarn feeding mechanisms, one to each feeder, each of said mechanisms comprising a single yarn measuring roller consisting of a frusto-conical inner portion having a surface adapted to enhance the frictional grip of a yarn wrapped therearound and a parallel-sided outer portion adjoining the small end of the said inner portion, said parallel-sided portion having a smooth surface to permit of slippage between the latter and the yarn in the event of it being engaged thereby for the purpose specified, and automatic yarn tension controlling means in the form of a rocking compensator furnished with depending guide means adapted to locate a lap of the yarn around the measuring roller and also with an upwardly directed guide to engage the run of the said yarn between the said depending guide means and the relevant feeder, the said controlling means being thereby influenced by variations in tension of the yarn during knitting, means positively driving all of the yarn measuring rollers at the same speed, and, in front of and substantially in line with the upper end of the upwardly directed guide on the rocking compensator of each yarn feeding mechanism, a stop motion device through which the yarn running from the said guide can pass.

8. For a knitting machine equipped with a plurality of feeders, a yarn feeding mechanism comprising, in combination, a single positively driveable yarn measuring roller consisting of a frusto-conical inner portion having a slip-resisting surface to enhance the grip of a yarn wrapped therearound on its Way from a supply to a feeder, and a parallel-sided outer portion adjoining the small end of the said inner portion, said parallel-sided portion having a smooth surface to permit of slippage between the latter and the yarn in the event of the yarn being passed therearound for the purpose specified, automatic yarn tension controlling means in the form of a rocking compensator furnished with depending guides adapted to locate a lap of the yarn around a desired portion of the measuring roller and also with an upwardly directed guide to engage the run of the said yarn between the depending guides and the aforesaid feeder, the said controlling means being thereby influenced by variations in tension of the yarn during knitting, means enabling the position of the upwardly directed guide relatively to the compensator to be varied, and pre-settable means enabling the degree of permitted rocking movement of the compensator to be varied, so that when a yarn wrapped around the frustoconical portion of the yarn measuring roller is to be positively fed at a varying maximum speed, the mechanism can be set to ensure that the depending guides shall be capable of swinging to and fro to an extent covering the full length of the said frusto-conical portion, whereas when less yarn is required to be fed this yarn is passed around the parallel-sided outer portion of the measuring roller and the compensator is set to have only a restricted degree of rocking movement whereby in this case the depending guides cover the parallel-sided portion and a small adjoining part only of the frusto-conical portion of the said roller.

References Cited in the file of this patent UNITED STATES PATENTS 2,158,547 Lawson et a1 May 16, 1939 2,233,914 Karns Dec. 3, 1940 2,537,000 Stibbe et al. Jan. 2, 1951 2,561,175 Brown July 17, 1951