GB2069016A

GB2069016A - Yarn feed devices

Info

Publication number: GB2069016A
Application number: GB8102049A
Authority: GB
Original assignee: BENTLEY ENG GROUP Ltd; Alan Shelton Ltd
Current assignee: BENTLEY ENG GROUP Ltd; Alan Shelton Ltd
Priority date: 1980-02-12
Filing date: 1981-01-23
Publication date: 1981-08-19

Abstract

A yarn feed device includes a storage drum (9) for a plurality of wound turns of yarn (Y), and yarn displacing members (10) adapted to displace wound turns of yarn progressively in a direction longitudinally of the drum which comprises a circle of longitudinally- disposed members (8). The yarn displacing members are movable with at least a component of motion longitudinally of said longitudinally- disposed members, and there are provided projections (26, 28) which protrude outwardly of the periphery of said drum (9) and over which turns of yarn (Y) pass during the passage of the yarn around the drum (9) of the feed device from a first zone (I) of turns immediately adjacent the yarn displacing members to a second zone (II) of turns spaced from the yarn displacing member (10), from which second zone yarn is taken off from the feed device. <IMAGE>

Description

SPECIFICATION Yarn feed devices The invention is concerned with improvements in or relating to yarn feed devices, for example devices having a yarn storage capacity.

Yarn feed devices are used in a variety of applications in the textile industry wherever a yarn or yarns is/are required to be fed to a machine under controlled tension, at either a uniform rate, a changeable rate or at intermittent intervals. A type of yarn feed device in common use is known as a yarn storage feeder and comprises a support in the form of a drum around which are wound a plurality of turns of the yarn as received from the bobbin and this stored yarn is pulled off in the required manner independently of the rate at which it was initially fed to the device.

In the specification of British Patent No.

1,583,241 there is described a yarn feed device of the above type comprising a storage drum adapted to accommodate a plurality of wound turns of yarn from a supply source, yarn displacing means adapted to displace wound turns of yarn progressively in a direction longitudinally of the drum and comprising a plurality of yarn displacing members movable with at least a component of motion longitudinally of the drum along paths defined by longitudinally disposed members arranged in circular formation around the periphery of the drum and a continuous cam surface adjacent said members engaging with said yarn displacing member so that relative rotary movement between the drum and the cam surface imparts lengthwise movement of the yarn displacing members relative to the longitudinally disposed members.

It is an object of the present invention to provide a yarn feed device which includes further features which tend to enhance the efficiency of devices of this type.

The invention provides a yarn feed device comprising a storage drum adapted to accommodate a plurality of wound turns of yarn from a supply source, a plurality of yarn displacing members adapted to displace wound turns of yarn progressively in a direction longitudinally of the drum, said drum comprising a plurality of longitudinally disposed members disposed in a circular formation around the periphery of the drum, said yarn displacing members being movable with at least a component of motion longitudinally of said longitudinally disposed members, means for so moving the yarn displacing members that relative rotary movement between the drum and the means for moving the yarn displacing members imparts lengthwise movement of the yarn displacing members relative to the longitudinally disposed members, there being provided projections which protrude outwardly of the periphery of said drum and over which turns of yarn pass during the passage of the yarn around the drum of the feed device from a firs zone of turns immediately adjacent the yarn displacing members to a second zone of turns spaced from the yarn displacing members, from which second zone yarn is taken off from the feed device.

Advantageously there may be provided a zone intermediate the first and second zones, in which intermediate zone the projections lie in a staggered array.

In one example of a device according to the invention, the projections may partake of lengthwise movement, which may, if desired, be identical and simultaneous with that of the yarn displacing members. Thus in an example of a device which is described hereinafter in detail, each projection is associated with one of the yarn displacing members in an assembly and in a first group of assemblies the distance between the projection and the associated member has a first value and in a second group, the members of which intervene between alternate members of the first group, the distance between the projection and the associate member has a second value.

Advantageously, the yarn feed device may be further provided with yarn tensioning means arranged to encircle the drum at a region adjacent a take-off point of the yarn from the drum, said tensioning means comprising a continuous band of flexible sheet material having a surface bearing a pile or nap lying at an oblique angle with respect to the surface of the sheet material, said pile or nap arranged to be in contact with the drum, the yarn passing between the band and the drum in a direction compatible with the direction of lie of the pile or nap.

Conveniently the band is a loop of low-pile fabric such as velvet or brushed velour.

In an example of the invention, the yarn displacing members are mounted for lengthwise sliding movement on the longitudinally disposed members which are in the form of rods or struts, inwardly projecting portions of the members engaging with a continuous cam surface formed within the drum.

The sliding movement of the yarn displacing members is controlled by the cam surface between a yarn entry level and a main level in which the members press the newly received yarn against the turns already stored on the drum. In an upright orientation of the drum in which the yarn take-off point is from the lower end of the drum, the main level is lower than that of the entry level and it is advantageous if this lower level extends at least halfway(1800) around the cam surface in order to even out the pressure exerted on the turns as much as possible, e.g. to minimise "overlapping" of the turns of yarn on the drum.

Conveniently, the rods of the drum may be arranged in pairs, each displacing member spanning the two adjacent rods of a pair for stability. As the drum continues to rotate, the members press the yarn until it is pressed against the turns already wound on to the drum, causing these turns to slide downwardly on the rods or struts.

The lowermost turn of yarn on the drum is taken off the drum according to the requirements of the machine to which the yarn is being fed.

As in the case of the device described in the above-mentioned specification it is normally arranged that the rate at which the yarn is wound on to the drum is greater than that at which it is taken off. While this ensures that there are always stored turns present on the drum it does necessitate control of the build-up of yarn in relation to the capacity of the drum, and at frequent intervals, the storage capacity will be taken up to a point where the winding movement must temporarily cease. In a preferred example of the invention, therefore, the drum is rotatably driven by a frictional drive arrangement comprising a co-axially driving wheel acting on the upper side of the top plate supporting the rods of the drum.When it is required to stop rotation of the drum, contact between the top plate and the wheel is interrupted in any suitable manner and the drive disconnected until further storage capacity is available.

There will now be described in detail an example of a yarn feed device according to the invention. It will be understood that the description which is to be read with reference to the accompanying drawings is given by way of example only and not by way of limitation.

In the drawings: Figure 1 shows a perspective view of a device according to the invention; Figure 2 shows a side view of the device of Figure 1 including a part section on line Il-Il of that Figure; and Figure 3 shows a fragmentary view, partly in section, of the zones of the device.

The Figures show a circular top plate 2 having a central annular mounting portion 4 positioned upon a shaft 6. Arranged around the periphery of the plate 2 are thirty-two longitudinally disposed members in the form of rods 8, arranged in pairs to define a plurality of longitudinal tracks. The rods 8 comprise a drum 9. Mounted so as to span adjacent ones of a pair of rods 8 are a plurality of yarn displacing members 10 having holes in which the rods freely pass. An inwardly projecting portion 12 of each member 10 are received in a stationary cam surface 14 formed in a cam member 1 6. The shape of the cam surface is such as to comprise a main lower level portion 1 8a which extends around approximately 1800 of the member 16 and a high-level portion 1 8b adjacent the feed-in point of a yarn Y, which is arranged between two oppositely sloping portions, 1 8c, 18d.

The plate 2 is normally held in frictional driving contact with a co-axial driving wheel 20, in the manner of a friction clutch, by means of a spring 21 acting between the under surface of the annular portion of the plate and an annular bearing 22 on the lower end of the shaft 6. The wheel 20 is driven by contact with a belt 24.

In operation the yarn Y is received on the drum 9 which, being in frictional driving contact with the wheel 20, is rotating and causes the yarn to be wound around the drum 9 formed by the rods 8 in a plurality of turns. As the yarn is received at the high level of the cam surface, the yarn displacing members 10 are in their higher position and the yarn commences to wind immediately below these members. As the members 10 travel along the surface 14 so they ride down the cam surface portion 1 8c (and therefore down the rods 8) until they reach the lower level 1 8a. In doing so they cause the fresh turn of yarn to be moved downwardly and to push against the previously wound turn to push all the turns downward in close contact.

However, it frequently happens that a certain amount of overlapping of the turns occurs possibly due to a siight flattening of the cross-section of the yarn as it is wound and this overlapping may cause uneven tension in the yarn as it leaves the drum, especially when a turn of yarn is still trapped beneath overlying turns when it is being drawn off. The members 10 are therefore provided with downwardly oriented wires 26 alternating with similarly orientated wires 28, which wires are shaped to provide projections in the form of angled portions wnich protrude outwardly beyond the rods 8.The wires 26 are provided with projections 30 at a distance a from the member 10 (see Figure 3) and the wires 28 with projections 32 at a distance b from the associated member 10 so that the projections lie in a staggered army. Thus the assemblies of the members 10 and their wires 26 provide said first group of assemblies, and the assemblies of the member 10 and their associated wires 28 provide said second group of assemblies.

The region of the drum formed by the rods 8, which lies immediately below the member 10 and which in operation receives the most recently wound turns of yarn is referred to hereinafter as zone I and is illustrated in Figure 3. The region from which wound turns are taken off from the device is referred to as zone II and the intervening zone in which the projections are arranged is referred to as zone ill.

Below the zone II on the rod is positioned a continuous band 34 of flexible knitted or woven fabric having a pile or nap on its inwardly facing surface. The pile or nap is laid obliquely with respect to the fabric of the band, and is arranged so that its direction is compatible with the passage of the yarn Y between the band and the rods 8 (Figure 2). A smoothly contoured ring 36 is provided on the lower edge of the drum, over which ring the yarn passes as it leaves the band 34.

In use, therefore, the yarn Y approaches the device through a guide eye 38 (Figures 1 and 2), passes through two tensioning means 40, and as the drum 9 rotates through frictional contact with the wheel 20, the yarn is wound therearound in a plurality of turns in zone I. As more turns of yard are received in zone I, so the earlier formed of these are pushed downwardly towards zone III and one by one are pushed over the projections 30 and 32. The slight elasticity of the yarn causes to spirng over the projection in a swift movement with what is often a noticeable component of downward motion.

This causes the turns of yarn to be separated and when they reach zone II, they are found to be in a much more even condition as regards both tension and lack of overlapping. The yarn Y is then drawn off, after having passed under the band 34 and over the ring 36, through a guide 42 to be received by the textile machine in a condition of uniform tension.

Claims

1. A yarn feed device including a storage drum adapted to accommodate a plurality of wound turns of yarn from a supply source, a plurality of yarn displacing members adapted to displace wound turns of yarn progressively in a direction longitudinally of the drum, said drum comprising a plurality of longitudinally-disposed members arranged in a circular formation around the periphery of the drum, said yarn displacing members being movable with at least a component of motion longitudinally of said longitudinally disposed members, means for so moving the yarn displacing members that relative rotary movement between the drum and the means for moving the yarn displacing members imparts lengthwise movement of the yarn displacing members relative to the longitudinally disposed members, wherein there are provided projections which protrude outwardly of the periphery of said drum and over which turns of yarn pass during the passage of the yarn around the drum of the feed device from a first zone of turns immediately adjacent the yarn displacing members to a second zone of turns spaced from the yarn displacing members from which second zone yarn is taken off from the feed device.

2. A device as claimed in claim 1 , wherein there is provided a third zone between the first and second zones of turns, said projections lying in said third zone in staggered array.

3. A device as claimed in either one of claims 1 and 2, wherein the projections, partake of lengthwise movement identical to and simultaneous with the lengthwise movement of the yarn displacing members.

4. A device as claimed in claim 3, wherein each projection is attached to one associated yarn displacing member for lengthwise movement therewith in an assembly.

5. A device as claimed in claim 4, wherein there is provided a first group of assemblies and a second group of assemblies, in the first group of assemblies the distance between each projection thereof and the associated yarn displacing member having a first value and in a second group, the yarn displacing members of which intervene between alternate yarn displacing members of the first group, the distance between each projection and the associated member yarn displacing in said second group having a second value.

6. A device as claimed in either one of claims 4 and 5 wherein each projection is formed on one of a series of wires, each wire extending from the associated yarn displacing member.

7. A device as claimed in any of the previous claims, wherein there is further provided yarn tensioning means arranged to encircle the drum at a region adjacent a take-off point of the yarn from the drum, said tensioning means comprising a continuous band of flexible sheet material having a surface bearing a pile or nap lying at an oblique angle with respect to the surface of the sheet material, said pile or nap arranged to be in contact with the drum, the yarn passing between the band and the drum in a direction compatible with the direction of lie of the pile or nap.

8. A device as claimed in claim 7, wherein the band is a loop of low-pile fabric material.

9. A device as claimed in any one of the previous claims wherein the drum is composed of a plurality of longitudinally extending rods which are arranged in pairs, each yarn displacing member spanning the two adjacent rods of each pair.

10. A yarn feed device including a storage drum, constructed and arranged substantially as hereinbefore with reference to and as shown in the drawings.