GB2102034A

GB2102034A - Yarn reservoir

Info

Publication number: GB2102034A
Application number: GB08119493A
Authority: GB
Inventors: Geoffrey Darnborough; Derek William Spence
Original assignee: Wool Development International Ltd
Current assignee: Wool Development International Ltd
Priority date: 1981-06-24
Filing date: 1981-06-24
Publication date: 1983-01-26
Also published as: GB2102034B

Abstract

A yarn measurer and store for the supply of flat yarn or tape to the weft input of a weaving loom in untwisted and substantially tensionless condition comprises a storage container 10 whose thickness is not substantially greater than the width of the yarn 24 having an inlet 18 and outlet 14, the yarn being supplied to the inlet by nip rollers 22 the drive to which is responsive to a sensing device such as a photocell 26 so as to maintain the storage container substantially full of yarn. The yarn may be taken from the outlet 14 directly to the weft input of a weaving loom. <IMAGE>

Description

SPECIFICATION Yarn reservoir This invention relates to a yarn reservoir and in particular relates to a reservoir suitable for holding flat weft yarn for weaving.

In weaving operations where the weft is a flat yarn or tape it is usually necessary to ensure that the tape remains flat and untwisted throughout the weft. This could be achieved when using a loom such as a rapier loom, by taking the weft tape directly from a reel, but the acceleration and deceleration of the yarn imposed by the weft cycle of a rapier loom can not easily be followed by a reel of yarn since inertia of the reel, particulariy when full or nearly full, is such that it cannot follow the rapid changes imposed by the rapier action. This means in practice that the yarn breaks, or the reel overruns causing yarn snarling, or at the very least the yarn tensions fluctuate greatly producing a woven cloth of poor quality.

The invention seeks to provide a reservoir for flat yarns or tape which will present the yarns to the weft feed of a loom in untwisted condition at substantially zero tension throughout the weaving cycle.

According to the present invention there is provided a yarn reservoir which comprises a storage container having an inlet and outlet, the inlet having driven feed means, and the drive of the feed means being responsive to a sensing device so as to maintain a predetermined level of yarn within the storage container from which it can be drawn untwisted in a substantially tensionless condition.

The apparatus of the invention is adapted to draw yarn from a reel of yarn mounted on a beam or axle for rotation so that twist is not inserted when drawing the yarn from the reel. The driven feed means of the apparatus of the invention does not subject the reel to the sort of acceleration it would be subjected to if it were connected directly to the loom weft feed, and it may therefore act a buffer between the reel of yarn and the loom weft feed enabling tapes or flat yarns successfully to be woven.

The storage container is preferably in the form of thin vertical box whose thickness is notsubstantially greater than the width of the yarn or tape which it is designed to hold thereby ensuring that succeeding loops of yarn do not overlap one another. The feed means may be any suitable mechanical feed device, for example feed rollers, which are driven, preferably by means of an electric motor. The feed means are driven in response to the output of a sensing device to maintain the reservoir substantially full of yarn. The sensing device may be, for example, a photocell arrangement which detects when the yarn level within the storage container reaches a certain limit; or may preferably consist of a reflectance type photocell which sends out a signal and receives a reflected signal proportional to the distance of the yarn from its sensing head.With the latter means it is possible, instead of merely stopping and starting the feed means, to control the speed of the feed means so that it slows down as the storage container approaches capacity and speeds up as the storage container starts to empty thereby maintaining the reservoir substantially full in a very smooth manner.

Yarn from the outlet from the storage container may be taken to the weft input of the weaving loom.

Yarn to the feed means at the input of the storage container may be taken from a conventional reel or beam since the apparatus of the invention ensures that the reel or beam will not be subjected to undue accelerations or decelerations.

The reservoir of the invention is suited to the weaving of any type of flat yarn or tape, for example flat polyethylene or polypropylene yarns, and is especially suitable for the weaving of strand reinforced paper tapes for fabric intended to be made up into containers such as wool bales.

The invention will be described further, by way of example, and with reference to the accompanying drawing in which the sole Figure is a front elevational view of a reservoir constructed according to the invention.

Referring to the drawing, the reservoir generally designated 10 comprises a vertical storage container 12 having a thickness not substantially greater than the width of the yarn or tape with which it is to be used, e.g. in the order of one ortwo millimeters. For instance the tape may be of 4.5mm width and the thickness of the reservoir 6.00mm. The container has an outlet 14 through which yarn may be drawn by, for example, the weft feed of a rapier loom. An internal baffle 16 is provided so that the yarn output may be taken from the bottom of the storage container 12 up to the outlet 14 without interfering with the remainder of the yarn within the container 14. A yarn input orifice 18 is provided having associated feed means 20 which comprises a pair of driven rollers 22 between which the yarn 24 passes.

The rollers 22 comprise a flanged roller 23 and a complementary roller 25 having a raised land portion adapted to fit between the flanges of the roller 23 and contact the latter's driving surface. Thus the tape yarn 24 is held against sideways movement between the rollers 22 by the flanges of roller 23. As is common with nip rollers, an adjustable biasing mechanism 27 is provided to set the nip pressure to the optimum level for a given yarn 24. As an alternative to nip rollers 22, a pair of driven belts may be provided. The main advantage of having belts is that any variations in yarn thickness, e.g. when using paper yarns, is more easily accommodated with belts without loss of drive. External guiding means may then be provided to keep the yarn between the belts. The belts may comprise two belt systems arranged in such a way that they grip the tape and feed it into the reservoir.The position of one of the belt systems may be fixed but the other may be pivoted under spring tension so that it forms a nip with the fixed system to grip the tape. The fixed belt system is positively driven and the pivoted system is driven from the fixed system by means of spur gears.

A sensing device 26 is located on the upper portion of the storage container 12. The device 26 is an opto-electric device responsive to the reflectance of any yarn 24 within the area of operation indicated at 28. The output from the device 26 is proportional to the distance at which it senses the yarn and this out put, via a suitable control circuitry, enables the nip rollers 22 to be driven at varying speed as the storage container 12 becomes full. An especially useful device 26 is a SUNX high resolution superanalogue sensor, series RS 120HF Z SAS, optical device and control unit PS 830SA.

The yarn 24 is taken to the feed means 20 from a conventional reel or beam of yarn (not shown in the drawing). Desirably, the reel or beam of yarn is driven by the same motor (again not shown) which drives the nip rollers 22, suitably geared. Furthermore, braking can be applied to the reel or beam when the feed means 20 is stopped or slowed down.

Thus the yarn may be drawn smoothly from the reel or beam into the apparatus 10 where a substantially tensionless reservoir is maintained for feed to the weaving loom.

To thread up the apparatus when starting, orto piecen up should a breakage occur, the front cover of the container 12 may be removed, or swung aside on hinges exposing the interior and enabling the operative to carry out th reading up. The fact that the container is not substantially thicker than the tape yarn employed prevents successive layers of yarn overlapping or intermingling, and helps prevent the yarn from twisting in the container. The yarn being drawn from a reel and passed directly through the feed rollers 22 and the storage container, without at any point inserting twist, ensures that it is presented at the container outlet in an untwisted condition.

The device of the invention enables a good quality fabric to be woven using flat tape weft yarn without introducing twist into the tapes.

Claims

1. A yarn reservoir which comprises a storage container having an inlet and outlet, the inlet having driven feed means, and the drive of the feed means being responsive to a sensing device so as to maintain the storage container substantially full of yarn from which it can be drawn untwisted in a substantially tension less condition.

2. A device as claimed in claim 1 in which yarn is taken through the inlet from a reel mounted on a beam or axle for rotation.

3. An apparatus as claimed in either of claims 1 or 2 in which the storage container is in the form of a thin vertical box whose thickness is not substantially greater than the thickness of the yarn or tape with which it is to be used.

4. An apparatus as claimed in any one of claims 1 to 2 in which the feed means comprises a pair of nip rollers.

5. An apparatus as claimed in claim 4 in which one of the nip rollers has flanges and the other of the nip rollers has a raised land portion adapted to fit snugly between the flanges on the first nip roller and contact the driving surface thereof.

6. An apparatus as claimed in any of claims 1 to 3 in which the drive means comprises a pair of drive belts.

7. An apparatus as claimed in any of claims 1 to 6 in which the sensing device is a photocell.

8. An apparatus as claimed in claim 7 in which the photocell is a reflectance type photocell which sends out a signal proportional to the distance of the yarn within the container from its sensing head.

9. An apparatus as claimed in claim 8 in which the drive to the driven feed means is variable in response to the output of the photocell.

10. An apparatus as claimed in any one of claims 1 to 9 in which the yarn from the outlet ofthe storage container is taken to the weft input of a weaving loom.

11. An apparatus as claimed in any one of claims 1 to 10 in which, in use, employs flat yarn ortape.

12. A yarn reservoir substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

12. An apparatus as claimed in claim 11 in which the flat yarn or tape is strand reinforced paper tape.

13. A method of supplying a yarn to the weft input of a weaving loom in an untwisted condition which comprises supplying untwisted yarn to a reservoir having a yarn inlet and a yarn outlet, sensing the yarn level within the reservoir and altering the supply rate accordingly, and taking yarn from the outlet of the reservoir to the weft input of the weaving loom.

14. A yarn reservoir substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

New claims or amendments to claims filed on 2-7-81, 2-8-82.

1. A yarn reservoir which comprises a storage container having an inlet and outlet, the inlet having driven feed means, and the drive of the feed means being responsive to a sensing device so as to maintain a reserve of yarn within the storage container from which it can be drawn untwisted in a substantially tensionless condition.

1. A yarn reservoir which comprises a storage container having an inlet and outlet, the inlet having driven feed means, and the drive of the feed means being responsive to a sensing device comprising a reflectance type photocell which sends out a signal proportional to the distance of the yarn within the container from its sensing head so as to maintain a reserve of yarn within the storage container from which it can be drawn untwisted in a substantially tension less condition.

7. An apparatus as claimed in any of claims 1 to 6 in which the drive to the driven feed means is variable in response to the output of the photocell.

8. An apparatus as claimed in any one of claims 1 to 7 in which the yarn from the outlet ofthe storage container is taken to the weft input of a weaving loom.

9. An apparatus as claimed in any one of claims 1 to 8 in which, in use, employs flat yarn or tape.

10. An apparatus as claimed in claim 9 in which the flat yarn or tape is strand reinforced paper tape.

11. A method of supplying a yarn to the weft input of a weaving loom in an untwisted condition which comprises supplying untwisted yarn to a reservoir having a yarn inlet and yarn outlet, sensing the yarn level within the reservoir and altering the supply rate accordingly, and taking yarn from the outlet of the reservoir to the weft input of the weaving loom.