US3862711A

US3862711A - Yarn feeding device for textile machines such as knitting machines and the like

Info

Publication number: US3862711A
Application number: US390197A
Authority: US
Inventors: Donald Smith; John Michael Shepherd
Original assignee: IWS Nominee Co Ltd
Current assignee: IWS Nominee Co Ltd
Priority date: 1970-07-29
Filing date: 1973-08-21
Publication date: 1975-01-28
Anticipated expiration: 1992-01-28

Abstract

A yarn feed device for a textile machine such as a knitting machine, the device being capable of feeding yarn over a range of feed rates and comprising a plane surface rotatable about an axis normal to the surface, a conical roller which is rotatable about an axis inclined to the surface and cooperating with the plane surface to define a nip, a drive for rotating the surface or the roller and a yarn guide adjustable to supply yar to the nip at different points along the nip, the yarn thereby being given a speed corresponding to the linear speed of the plane surface at the point of supply.

Description

United States Patent 11 1 A Smith et a1.

1 1 YARN FEEDING DEVICE FOR TEXTILE MACHINES SUCH AS KNITTING MACHINES AND THE LIKE [75] Inventors: Donald Smith; John Michael Shepherd, both of llltlcy. England [73] Assignee: I.W.S. Nominee Company Limited, London. England 221 Filed: Aug. 21. 1973 211 App]. 190.; 390,197

Related US. Application Data [63] Continuation-impart of Ser. No. 166.134. July 26.

1971, abandoned.

130] Foreign Application Priority Data July 29, 1970 Great Britain 36773/70 [52] US. Cl. 226/184, 66/132 R [51] Int. Cl D04b 15/48 [58] Field of Search 66/132 R, 132 T; 226/184; 74/532, 194

[56] References Cited UNITED STATES PATENTS 9/1915 Boal..... 1. 74/532 5/1925 Willis r 74/532 X 7/1938 Lindley .1 66/132 R 1 1 Jan. 28, 1975 Primary Examiner-Robert R. Mackey Attorney, Agent. or Firm-Cameron. Kerkam. Sutton.

'Stowell & Stowell 571 ABSTRACT A yarn feed device for a textile machine such as a knitting machine, the device being capable of feeding yarn over a range of feed rates and comprising a plane surface rotatable about an axis normal to the surface, a conical roller which is rotatable about an axis inclined to the surface and cooperating with the plane surface to define a nip, a drive for rotating the surface or the roller and a yarn guide adjustable to supply yar to the nip at different points along the nip, the yarn thereby being given a speed corresponding to the linear speed of the plane surface at the point of supply.

3 Claims, 4 Drawing Figures YARN FEEDING DEVICE FOR TEXTILE MACHINES SUCH AS KNITTING MACHINES AND THE LIKE This application is a continuation-in-part of our application Ser. No. 166,134 filed July 26, 1971, now abandoned.

BACKGROUND OF THE INVENTION An increasing number ofjersey fabrics are knitted on circular machines and many of these machines nowadays are fitted with positive feed devices which feed yarn to the needles at a controlled rate. With the adoption of positive feeding, the loop length, which is the basic parameter of fabric quality and dimensions, becomes essentially independent of all other variables including yarn tension, yarn friction and machine cam setting. Furthermore, the current tendency is towards fine fabrics which require finer yarns and as a consequence the possibility of yarn break is much higher and the need for positive feed much greater.

The number of feed points on a multifeed circular knitting machine, which correspond to the number of courses knitted on the machine at any one time, range from 1 to 48 or more. Normally, they have 36 or 48 feed points.

One of the most widely used positive feed devices comprises a driven endless belt which is wrapped around a series of freely rotatable drums, one drum for each feed point on the knitting machine. Yarn is passed between the driven belt and the drum and is fed to the needles at a speed equal to the belt speed. The belt speed can be varied but it is the same for each feed point. In setting up the machine it would be preferable to be able to individually alter the feed speed for each feed point, but with this type of positive feed it is impossible and has to be achieved by other means, e.g. by adjustment of the cam setting.

Only the simplest fabric structures, for example, interlock and simple ribs, can be knitted with a single yarn speed. Other fabrics, for example Ponti-di-Roma and piques, require two or more yarn speeds. To cope with this situation machines are provided with banks of I drums above each feed point, each drum being capable of being driven at a different rate from the endless belt on that particular level. In practice, however, there is room for at most four drums above each feed point and usually only two or three. While these do provide a variation in the number of feed rates at which yarn can be fed to the needles, they produce a very limited pattern range and cannot be used on machines employing a Jacquard mechanism. Normally, Jacquard knitting machines require such a large range of feed rates that positive feed arrangements, though very desirable, are not available and cannot therefore be used THE PRESENT INVENTION A yarn feed device has now been developed which is capable of feeding yarn over a wide range of feed rates and is suitable for use on a knitting machine employing a Jacquard mechanism as well as on many other knitting machines.

According to the invention, a yarn feed device for a I textile machine comprises a plane surface rotatable about an axis normal to the surface, a conical roller which is rotatable about an axis inclined to the surface and cooperates with the plane surface to define a nip, a drive for rotating the surface or the roller (or both,

if identical surface speeds at the nip can be ensured) and a yarn guide arranged to supply yarn to the nip at a selected point along the nip whereby the yarn is given a speed corresponding to the linear speed of the plane surface at the point of supply.

The plane surface is most conveniently in the form of a disc rotatable about its central axis. The conical roller may have the form of either a complete or a truncated cone, but it will be appreciated that the conical form must be regular with respect to the axis of rotation of the roller. The inclination and disposition of such axis in relation to the axis of rotation of the plane surface must be such as to ensure substantial correspondence of the linear speeds of the plane surface and the conical roller along the length of the nip.

A wide range of yarn speeds for such roller may be selected by adjusting the position of the yarn guide along the roller. Thus, if a point near the tip of the conical roller is selected, the speed of the conical surface and hence the rate of feed will be much less than if a point near the base of the roller is selected.

Theplane surface and the conical roller are preferably urged together and more preferably controllably biassed in such a way that the pressure in the nip can be'varied, or if necessary released altogether. Such a variation in nip pressure is desirable in order to render the feed device suitable for all types of yarn.

The plane surface of the disc orthe conical roller or both preferably have a resilient or friction-imparting surface in order to avoid yarn slippage in the nip. This may be achieved by making the roller from rubber or similar material, or employing a rubber or other elastomeric sleeve on the roller. It is particularly simple and advantageous to cover the surface of the rotating disc with a resilient or friction-imparting material. The yarn .guide is preferably provided with means to set the guide BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of one embodiment of the yarn feed device according to the invention;

FIG. 2 is a perspective view of another form of the present invention;

FIG. 3 is a vertical sectional view of the device shown in FIG. 2; and

FIG. 4 is an elevational view of a further form of the yarn feed mechanism of the invention.

DESCRIPTION OF THE EMBODIMENTS In the device 10 shown in FIG. I, a disc 12 having a flat surface 14 is mounted for rotation about a horizontal axis and is driven by a belt 16 passing around the periphery of the disc. The disc may alternatively be driven through a pulley secured coaxially with the disc as to be more fully described hereinafter.

A conical roller 18 is rotatable about an inclined axis and either the conical surface of the roller 18 or the flat surface 14 of the disc 12 or both may be covered with resilient material again as to be more fully described hereinafter. In practice, it is simplest to coat the surface 14 of the disc. The roller 18 and the surface 14 of the disc make contact along a line which is a radius of the disc and in order to ensure that there is no slippage between the cone and the disc, the axis of the cone passes through the intersection of the axis of the disc with the plane of its flat surface 14. The cone is mounted on axle 20 to a bracket 22 for free rotation about its axis.

A yarn guide 24 is mounted in a position to feed yarn into the nip between the disc 12 and the conical roller 18 and is movable along the line of the nip. For this purpose the guide 24 is carried on a rack 26 which slides in the frame structure 28 associated with the bracket 22. The position of the rack is controlled and adjusted by means of a pinion which is itself actuated by a knurled knob 30. The yarn guide 24 may be mounted in other ways to secure the desired movement along the nip.

It may not be possible to ensure exact alignment of the axis of the yarn guide tube with the nip and in order to minimize the difficulty the orifice at the end of the tube where the yarn leaves the guide should be disposed close to the surface 14 of the disc as shown.

In operation the disc 12 is driven at a constant speed by the belt 16 moving in the direction of the arrows. Yarn from a supply package (not shown) is threaded through the yarn guide and passes through the nip between the disc 12 and the conical roller 18 to the point where a yarn supply is required, for example the feed point of a weft-knitting machine.

By reason of the radial direction on the surface 14 of the disc 12 of the line of contact with the conical roller 18 the linear speed of the nip surfaces varies uniformly along the line of the nip. A yarn speed appropriate for the knitting operation or for a particular part of the knitting cycle can thus be selected by adjusting the position of the yarn guide 24 along the line of the nip.

Another form of device according to the invention is shown, by way of example, in FIGS. 2 and 3.

The frame 40 of the unit 10' carries a slidable vertical rod 42 which is movable along its own axis. The upper part of the frame 44 carries an inclined, partly threaded rod 46 which is secured to the frame by two nuts 48 and 50. The lower end of the rod 46 carries a cone 52, supported on two axially spaced,

rotary bearings

52a, 52b.

The slidable rod 42 carries a hollow pulley 54, integral with which is a horizontal flat disc 56. The hollow pulley and disc are supported by two spaced

rotary bearings

60a and 60b.

The rod 42 has a washer 62 and a compression spring 64 mounted on it, the washer being located by a pin 66 so that the spring 64 is compressed between the washer 62 and the frame 40. This causes the disc 56 to be held in contact with the cone 52.

The lower end of the rod.42 is slotted, and mounted in the slot is a lever 70, secured by a pin 72. Movement of the lever 70 causes the profiled end 74 to bear against the frame and to draw the rod 42 downwards, thus separating the disc 52 from the cone 56.

The unit is driven by means of a belt (not shown) in contact with the pulley 54. Yarn is led between the surface of the disc 56 and the cone 52 through a yarn guide 76, the position of which is controlled by rotation of a knurled nut 78 acting on a threaded rod 80 to which the yarn guide is fixed. After passing through the nip between the cone and disc surface, the yarn is lifted clear of the surface by a second guide 82 and thence it is passed to the feeder of the knitting machine (not shown).

The following are the adjustments which can be made to the yarn feeding device shown in FIGS. 2 and 3.

Changes to the pressure between the cone 52 and disc 56 can be made either by changing the spring 64, by altering the degree of compression by moving the pin 66, or by inserting additional washers 62 between the spring and the pin.

Correct location of the cone relative to the disc is achieved by adjustment of the positions of the two nuts 48 and 50. The hole in the frame through which the rod 46 passes is preferably made oversize so that lateral adjustment is also possible.

The contact between the cone 52 and disc 56 depends on the angle at the bend between the upper part 44 and the lower part 44' of the frame 40. If it is found difficult to reproduce this angle in multiple production, either or both of the

bearings

52a and 60a may be removed. The play thus introduced into the mountings of the disc and cone allows them to locate one to the other to form the required linear nip.

A preferred embodiment of our invention is illustrated in FIG. 4. In this form of the invention, positive drive means are provided for the disc or plate so that yarn feed can be brought up to speed or stopped without slippage which slippage, as hereinbefore set forth, often results in yarn breakage. Further, in this form of the invention a more positive drive between the flat surface of the disc or plate and the active surface of the cone is provided.

In FIG. 4 the yarn feed device 10" comprises a disc or plate having its upper surface provided with a resilient rubber-like coating 82. The disc 80 is rotated by a pulley 84 provided with a plurality of uniformly spaced and radially projecting pins or pips 86 which engage openings 88 in a drive belt 90. The disc 80 and its connected pulley 84 are mounted for rotation on a shaft 92 secured to the platform 94.

The assembly also includes a cone 96 which preferably has its conical surface roughened such as by sandblasting or otherwise coated with a high friction material to insure positive engagement between the conical surface and the rubber-like composition 82 on the upper surface of the disc 80.

The cone 96 is mounted for rotation on a shaft 98 which mounting may include bearings such as shown in FIG. 3 of the drawings. The extended end of the shaft 98 is threaded as shown and is adjustably mounted to the upper end 100 of a lever arm 102 by a pair of

nuts

104 and 106. The lever arm 102 is pivotally mounted by a cross shaft or pivot pin 108 to an arm 110, the lower end of which is rigidly secured to the frame 94. A spring 112 has one end connected, as at 114, to the bracket or arm and the other end is pin-connected, as at 116, to the lever arm 102 between the pivot shaft 108 and shaft 98 whereby the cone is positively depressed onto the surface of the disc 80.

The arm or bracket 110 also has secured thereto, a leaf spring 118, by fastener 120. The leaf spring 118 is formed with a depression 122. The lever arm 102 has a lower extension 124 which is so positioned relative to leaf spring 118 and its depression 122 that when it is desired to inactivate the cone 96 and its yarn feed function, lever arm end 124 is depressed and held in the depressed position by the spring depression 122 thus overcoming the force of spring 112.

It will be recognized by those skilled in the art that in view of the positive drive for the disc or plate 80 it is possible to press the cone at greater force against the disc and since the disc has a deformable or resilient upper surface it will take up any small irregularities in manufacture of the device and grip the yarn to be fed at any point along the nip.

Not shown in FIG. 4 is the adjustable yarn guide which may be configured as shown in FIGS. 1 or 2 of the drawings.

From the foregoing description of various embodiments of the present invention, it will be seen that the yarn feed mechanism fully accomplishes the aims and objectives hereinbefore set forth to thereby provide a simple, relatively cheap, fully speed variable, positive yarn feeder which may be readily adopted to new or old knitting machines. It will also be recognized that various modifications may be made in the feed device without departing from the scope of the present invention.

We claim:

1. A yarn feed device for knitting and the like textile machines comprising:

a circular plate having a plane surface;

means supporting said plate for rotation about an axis normal to said surface;

at least one conical roller;

a lever supporting said conical roller for rotation about its axis, said axis being inclined to and intersecting the axis of rotation of said surface and said roller bodily cooperatively engaging said surface radially thereof so as to define therewith a nip, the line whereof intersects said axes of rotation of said surface and said conical roller at the point of intersection of said axes;

drive means for rotating at least one of said plate and said roller about said axis thereof;

a yarn guide located in yarn supplying relation to said nip and being adjustable along the length of said nip and means for so adjusting said guide whereby said yarn can be given a speed corresponding to the linear speed of said surface at the point of yarn sup- P y;

means pivotally mounting said lever intermediate its ends on the plate supporting means for pivotal movement about an axis normal to the axis of rotation of the circular plate;

said lever being substantially vertically disposed and having an upper end above the pivotal mount supporting the conical roller for rotatable movement;

spring means connected between the plate supporting means and the upper portion of the lever above the pivot point for constantly urging said upper end down toward the plate so as to constantly urge said conical roller into engagement with the plate; and

a spring latch mounted on and outstanding from the plate supporting means and with which the lower portion of the lever below the pivot point is adapted to cooperate so as to hold the lever in a locked position with the roller out of engagement with the plate.

2. The invention defined in claim 1 wherein the drive means includes a positive drive for rotating said plate.

3. The invention defined in claim 1 wherein said plane surface of said circular plate is resilient and the surface of the conical roller is roughened.

Claims

1. A yarn feed device for knitting and the like textile machines comprising: a circular plate having a plane surface; means supporting said plate for rotation about an axis normal to said surface; at least one conical roller; a lever supporting said conical roller for rotation about its axis, said axis being inclined to and intersecting the axis of rotation of said surface and said roller bodily cooperatively engaging said surface radially thereof so as to define therewith a nip, the line whereof intersects said axes of rotation of said surface and said conical roller at the point of intersection of said axes; drive means for rotating at least one of said plate and said roller about said axis thereof; a yarn guide located in yarn supplying relation to said nip and being adjustable along the length of said nip and means for so adjusting said guide whereby said yarn can be given a speed corresponding to the linear speed of said surface at the point of yarn supply; means pivotally mounting said lever intermediate its ends on the plate supporting means for pivotal movement about an axis normal to the axis of rotation of the circular plate; said lever being substantially vertically disposed and having an upper end above the pivotal mount supporting the conical roller for rotatable movement; spring means connected between the plate supporting means and the upper portion of the lever above the pivot point for constantly urging said upper end down toward the plate so as to constantly urge said conical roller into engagement with the plate; and a spring latch mounted on and outstanding from the plate supporting means and with which the lower portion of the lever below the pivot point is adapted to cooperate so as to hold the lever in a locked position with the roller out of engagement with the plate.