GB1597134A

GB1597134A - Method of presenting yarn ends at a seizing station and a guide for use in the method

Info

Publication number: GB1597134A
Application number: GB1127577A
Authority: GB
Original assignee: Bond Worth Ltd
Current assignee: Bond Worth Ltd
Priority date: 1978-04-25
Filing date: 1978-04-25
Publication date: 1981-09-03

Description

(54) METHOD OF PRESENTING YARN ENDS AT A SEIZING STATION AND A GUIDE FOR USE IN THE METHOD (71) We, BOND WORTH LIMITED, a British Company, of Severn Valley Mills, Stourport on Severn, Worcestershire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a method of presenting a row of yarn ends at a seizing station where the ends are seized and moved to draw off yarn from a spool, and to a guide for use in the method.

In a common method of manufacturing carpets, there is wound onto each one of a large number of spools a number of yarns equal to the number of pile tufts in a weftwise extending row in the finished carpet. When the required length of each yarn has been wound onto a spool, a portion of each yarn adjacent to the spool is inserted into a yarn clamp, the yarns are severed adjacent to the clamp and the clamp is releasably attached to the spool. The clamp then prevents inadvertent unwinding of the yarns from the spool during subsequent handling. The clamp has an elongate body from which there projects a row of dents, there being between each adjacent pair of dents a slot into which one yarn is received.

The yarns are inserted into the slots by relative movement of the yarns and clamp in a direction transverse to the lengths of the yarns. When each yarn has entered its slot in the damp a cap is applied to the dents to close the open ends of the slots and so prevent the yarns moving out of the clamp in a direction transverse to their lengths. Longitudinal movement of the yarns relative to the clamp is inhibited by friction between the clamp and the yarns.

The clamps which are generally used in this known method are formed from sheet metal, the thickness of which is somewhat less than the thickness of the yarn which is to be held by the clamp. Thus, although the clamp is able to control within close limits the spacing between adjacent yarns where these pass through the clamp, a clamp does not exercise close control over the positions of the free ends of the yarns which are spaced somewhat from the clamp. The clamp may also fail to exercise close control over the position of each yarn along its slot in the clamp. Inability of the clamp to control precisely the positions of the yarns does not impair the ability of the clamp to prevent the yarns unwinding from the spool.

When the yarns which have been wound onto the spool are required for use, the spool is mounted on a tube frame and each yarn is threaded through a respective guide tube of the tube frame. The threading operation is carried out by passing a row of hooked threading needles each through a respective one of the guide tubes and between the yarns so that on reverse movement of the threading needles, each needle hooks one yarn and draws that yarn through the corresponding guide tube. The hooks engage with the yarns close to the clamp. Accordingly, the control which the clamp exercises over the positions of the yarns is sufficient to ensure that each yarn will be properly engaged by the corresponding threading needle. Once the yarns have been threaded through their respective guide tubes, the cap is removed from the clamp and the clamp is removed from the yarns.

Each guide tube has a length which is a plurality of times greater than its diameter and a diameter which corresponds to that of the yarn so that contact is established between the guide tube and yarn throughout the length of the guide tube. In this way, the guide tube is able to ensure substantial coincidence of the axis of that portion of the yarn which is disposed within the guide tube with the axis of the tube itself and also to exercise good control over the position of a portion of the yarn which projects from the guide tube, provided that a free end of the yarn is spaced only a short distance, say one inch, from the guide tube. The guide tubes are used to ensure that the free end of each yarn occupies a predetermined position where it can be seized by a corresponding gripper.

There has been proposed in published.

specification No. 445,773 means which does not incorporate a tube but is intended for guiding the yarn to a gripper. The means disclosed in the prior specification comprises a generally U-shaped guide member in which there is formed a plurality of slots, one slot to receive each yarn. Open ends of the slots are formed in the base of the U-shape and the slots extend therefrom into both limbs of the U. To prevent yarns which have been inserted into the slots from moving towards the open ends thereof, there is provided outside the U shape and close to one limb thereof a respective triangular element for each slot, the flat faces of each element being approximately parallel to the adjacent limb of the guide member. These triangular elements cover a part of the adjacent slot extending from a position near to the closed end thereof to a position near to the open end thereof.Once a yarn has been moved to the closed end of its slot, the triangular element prevents inadvertent movement of the yarn away from the closed end.

It is suggested in specification 445,773 that the guide means disclosed therein may be removed from the spool frame and used for preventing unwinding of yarns from a spool onto which they have been wound. In practice, the guide means disclosed in the published specification is not satisfactory for this purpose because each slot is obstructed by the associated triangular element and it is.

necessary for each yarn to be manipulated individually into its slot. This is in contrast with the application of a clamp to the yarns by moving the clamp in a direction transverse to the lengths of the yarns whilst the latter are all maintained in a rectilinear configuration.

A further disadvantage of the guide means described in the published specification is that the degree of accuracy with which it locates the free ends of the yarns is not always satisfactory. It is necessary for the grippers which are used in conjunction with the prior proposed guide means to open widely in order to ensure that each yarn will be gripped. Machines which operate relatively slowly can have grippers which open widely but wide opening of the grippers becomes more difficult as the intended operating speed of the machine is increased.

According to a first aspect of the invention, there is provided a guide for guiding a plurality of yarns to a seizing station, the guide defining a row of yarn-receiving formations with respective axes which are parallel to each and are transverse to the length of the row, each formation being defined by a concave surface which extends around the axis, is interrupted at one side of the axis by a gap to admit the yarn to the formation and has a length (measured in a direction along the axis) greater than the mean distance of the surface from the axis, the guide further defining a plurality of substantially unobstructed tapered slots, one leading to each gap, and each slot having a narrower end at said gap and an open wider end remote from the gap The substantially unobstructed slots enable respective lengths of each yarn to be introduced into the yarn-receiving forme tions whilst the configuratins of such length is rectilinear.

Preferably, said concave surface engages the yarn, in use, at two positions spaced apart along the axis by a length greater than the mean distance of the surface from the axis and also engages the yarn between said positions. The surface may be continuous between said two positions, but it would be within the scope of the invention for said surface to be interrupted between said positions.

Said positions are preferably spaced apart by a distance of at least twice the means distance of the concave surface from the axis.

Adjacent to said gap, the concave surface preferably coincides with an arc centered on the axis of the formation.

According to a second aspect of the invention, there is provided a method of presenting a row of yarn ends at a seizing station wherein a plurality of yarns are wound on to spool side by side, portions of the yarns are inserted into respective yarnreceiving formations of a yarn guide, the guide is releasably attached to the spool, the guide prevents inadvertent unwinding of the yarns from the spool and free end portions of the yarns are subsequently presented in respective predetermined positions at the seizing station by moving the spool and the guide into positions adjacent to the seizing station, wherein the yarns are inserted into the guide by relative movement of the yarns and guide in a direction transverse to the lengths of the yarns whilst portions of the yarns in the vicinity of the guide are maintained in a substantially rectilinear configuration and, at the seizing station, the direction in which a free end portion of each yarn projects is controlled by the guide.

During insertion of each yarn into the corresponding yarn-receiving formation of the guide, relative movement of the yarn and guide in the direction lomgitudinally of the yarn preferably occurs during said relative movement in a direction transverse to the length of the yarn.

The invention will now be described, by way of example, with reference to the accompanying drawings wherein: FIGURE 1 shows an end elevation of a guide in accordance with the invention, together with a support for the guide and for an associated spool carrying yarns and showing also grippers for seizing an end portion of a yarn, and FIGURE 2 shows on a larger scale a perspective view of a part of the guide.

The apparatus illustrated in Figure 1 comprises a rigid, hollow, elongate support 10 which has a rectangular cross-section. At each of its ends, this support is provided with means (not shown) for releasably mounting the support on a pair of chains (not shown) which carry a number of supports identical with the support 10. The chains are guided for movement along respective paths such that each support can be brought near to a seizing station 11 at which free end portions of a plurality of yarn are to be presented and then seized in grippers 12. The mounting of tube frame on chains in a like manner is well known in the carpet-making industry.

Projecting from opposite ends of the support 10 in a direction transverse to the length thereof are two brackets 13 which releasably support a spool 14. The spool is of a type well known in the carpet-making industry and comprises an elongate core having near to each of its end a disc 15 disposed at rightangles to the length of the core. When supported by the bracket 13, the spool is rotatable about its axis 16 which is parallel to the length of the support 10.

A yarn guide 17 is releasably mounted on that face of the support 10 which is remote from the spool 14. The guide may be secured to the support by spring clips 18, by screw fasteners or in any other convenient manner.

The length of the guide is slightly greater than the distance between the discs 15 of the spool. As shown in Figure 2, the guide is formed with a row of yarn-receiving formations 19, the length of the row being parallel to the length of the guide and the formations being situated approximately midway between the long edges of the guide. Each formation 19 is defined by a respective concave surface 20 of the guide, this surface being part-cylindrical and subtending at an axis of the formation an angle of somewhat less than 360 but greater than 300". The respective axes of the formations 19 are parallel to each other.

At one side of each formation 19, the upper side in Figure 2, there is a gap 21 through which a yarn can be admitted to the formation. The width of the gap is considerably less than the diameter of the formation, preferably only one quarter of the diameter.

Portions of the surface 20 which lie on opposite sides of the gap and extend up to the gap are formed to coincide with an arc centered on the axis of the formation 19. This ensures that a yarn which substantially fills the formation 19 cannot easily pass through the gap 21 out of the formation.

Each gap 21 leads from the associated formation 19 to a respective slot 22 defined by the guide. Each slot 22 diverges from the gap in a direction away from the associated formation 21 to an edge of the guide 17 at which adjacent slots 22 are separated by a corresponding apex 23 of the guide. The apex is of rounded form. At the edge of the guide, the width of each slot 22 is somewhat greater than the diameter of the corresponding yarn-receiving formation 19.

The length of each of the formations 19 is sufficient to ensure that the longitudinal axis of the portion of yarn which substantially fills the formation coincides with the axis of the formation itself. The distance between positions at opposite ends of the formation at which the concave surface defining the formation engages the yarn is at least greater than the radius of the formation and is preferably greater than the diameter of the formation. For example, in a case where the diameter of the formation is less than 0.1 inch, the thickness of the guide 17 and therefore the length of each formation 19 may be 0.375 inch. Except for the interruption which constitutes the gap 21, the concave surface which defines a formation 19 is uninterrupted between its ends.Because this concave surface engages the yarn at positions between the ends of the surface, the yarn is maintained in substantially coaxial relation with the formation 19 along the entire length of that formation. This would not necessarily be the case if the only positions at which the guide engaged with the yarn were at opposite ends of the formation.

The apparatus illustrated in Figure 1 is used in the following manner to present a row of yarn ends at the seizing station 11.

The required number of yarns are wound onto the spool 14 in a known manner, each yarn being wound onto the spool at a selected position between the discs 15 and the number of yarns wound onto unit length of the spool (the pitch of the yarns) corresponding to the pitch of tufts of the yarn to be provided in a carpet. A predetermined tension is maintained in that portion of each yarn which is approaching the spool so that such portions are rectilinear. Just before the required length of each yarn has been wound on to the spool the guide 17 is moved in a direction transverse to the lengths of those rectilinear portions of the yarns which are approaching the spool to cause each yarn to enter a respective one of the slots 22.As longitudinal movement of each yarn and transverse movement of the guide continues, each yarn moves down its slot 22 and through the corresponding gap 21 into the associated formation 19. Movement of both the yarns and guide is then terminated and the yarns are severed at the side of the guide remote from the spool to leave a free end portion of each yarn projecting from the guide. The guide is then releasably attached to the spool and the latter is removed from the apparatus in which the winding of the yarns onto the spool has been performed.

The diameter of the formations 19 is selected in accordance with the thickness of the yarns being used so that each yarn fills its formation 19 and is in contact with the entire surface 20 thereof. There is sufficient friction between the yarns and the guide to prevent inadvertent movement of a yarn out of the guide. Thus, the guide is able to prevent inadvertent unwinding of the yarns from the spool.

When the yarns which have been wound onto the spool are required for use, the spool is mounted on the support 10 and the guide 17 is detached from the spool and is mounted directly on the support 10 by means of the clips 18. The formations 19 are clear of the support 10 and the axis of each formation 19 is at least approximately tangential to the windings of yarn on the spool.

The support 10 is mounted on the chains hereinbefore referred to and by movement of the chains is brought to a predetermined position near to the seizing station 11, so that the free end portions of the yarns which project from the guide 17 are presented at the seizing station.

The yarns tend to assume a rectilinear form, although small forces are sufficient to bend them. Nevertheless, the weight of the end portion of each yarn which projects from the guide 17 is so small that gravity does not have a significant effect on the configuration of the end portion of the yarn. By maintaining a coaxial relation between that part of each yarn which is disposed within a formation 19 and the formation itself, the position of the free end of the yarn can be controlled within close limits, sufficiently close limits to ensure that the end portion will be received between the grippers 12 when the latter approach the yarns at the seizing station. The grippers are preferably of the form described and claimed in our published Patent Specification No. 1,421,061.When the grippers have seized the yarns, they withdraw from the guide 17 to draw a required length of yarn from spool 14. A knife then cuts the yarns between the grippers and the guide, leaving once more a free end portion of each yarn projecting from the guide. The friction established by virtue of the closely embracing relation of the surfaces 20 and the yarns is sufficient to prevent any tension which may be established in the yarn between the guide and spool from drawing free end portions back into the guide 17.

The pitch of the formulations 19 along the guide is equal to the pitch of the yarns along the spool 14. The diameter of each formation is preferably slightly less than the thickness of the yarn with which it is to be used.

WHAT WE CLAIM IS: 1. A guide for guiding a plurality of yarns to a seizing station, the guide defining a row of yarn-receiving formations with respective axes which are parallel to each other and are transverse to the length of the row, each formation being defined by a concave surface which extends around the axis, is interrupted at one side of the axis by a gap to admit the yarn to the formation and has a length (measured in a direction along the axis) greater than the mean distance of the surface from the axis, the guide further defining a plurality of substantially unobstructed tapered slots, one leading to each gap, and each slot having a narrower end at said gap and an open wider end remote from the gap.

2. A guide according to Claim 1 wherein said concave surface engages the yarn in use at two positions spaced apart along the axis by a distance greater than the mean distance of the surface from the axis and also engages the yarn between said positions.

3. A guide according to Claim 2 wherein the surface is continuous between said positions.

4. A guide according to Claim 2 or Claim 3 wherein said positions are spaced apart by a distance of at least twice the mean distance of the concave surface from the axis.

5. A guide according to any preceding claim wherein, adjacent to said gap, the concave surface coincides with an arc centered on the axis of the formation.

6. A method of presenting a row of yarn ends at a seizing station wherein a plurality of yarns are wound on to a spool side by side, portions of the yarns are inserted into respective yarn-receiving formations of a yarn guide, the guide is releasably attached to the spool, the guide prevents inadvertent unwinding of the yarns from the spool and free end portions of the yarns are subsequently presented in respective predetermined positions at the seizing station by moving the spool and the guide into positions adjacent to the seizing station, wherein the yarns are inserted into the guide by relative movement of the yarns and guide in a direction transverse to the lengths of the yarns whilst portions of the yarns in the vicinity of the guide are maintained in a substantially rectilinear configuration and, at the seizing station, the direction in which a free end portion of each yarn projects is controlled by

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. transverse movement of the guide continues, each yarn moves down its slot 22 and through the corresponding gap 21 into the associated formation 19. Movement of both the yarns and guide is then terminated and the yarns are severed at the side of the guide remote from the spool to leave a free end portion of each yarn projecting from the guide. The guide is then releasably attached to the spool and the latter is removed from the apparatus in which the winding of the yarns onto the spool has been performed. The diameter of the formations 19 is selected in accordance with the thickness of the yarns being used so that each yarn fills its formation 19 and is in contact with the entire surface 20 thereof. There is sufficient friction between the yarns and the guide to prevent inadvertent movement of a yarn out of the guide. Thus, the guide is able to prevent inadvertent unwinding of the yarns from the spool. When the yarns which have been wound onto the spool are required for use, the spool is mounted on the support 10 and the guide 17 is detached from the spool and is mounted directly on the support 10 by means of the clips 18. The formations 19 are clear of the support 10 and the axis of each formation 19 is at least approximately tangential to the windings of yarn on the spool. The support 10 is mounted on the chains hereinbefore referred to and by movement of the chains is brought to a predetermined position near to the seizing station 11, so that the free end portions of the yarns which project from the guide 17 are presented at the seizing station. The yarns tend to assume a rectilinear form, although small forces are sufficient to bend them. Nevertheless, the weight of the end portion of each yarn which projects from the guide 17 is so small that gravity does not have a significant effect on the configuration of the end portion of the yarn. By maintaining a coaxial relation between that part of each yarn which is disposed within a formation 19 and the formation itself, the position of the free end of the yarn can be controlled within close limits, sufficiently close limits to ensure that the end portion will be received between the grippers 12 when the latter approach the yarns at the seizing station. The grippers are preferably of the form described and claimed in our published Patent Specification No. 1,421,061.When the grippers have seized the yarns, they withdraw from the guide 17 to draw a required length of yarn from spool 14. A knife then cuts the yarns between the grippers and the guide, leaving once more a free end portion of each yarn projecting from the guide. The friction established by virtue of the closely embracing relation of the surfaces 20 and the yarns is sufficient to prevent any tension which may be established in the yarn between the guide and spool from drawing free end portions back into the guide 17. The pitch of the formulations 19 along the guide is equal to the pitch of the yarns along the spool 14. The diameter of each formation is preferably slightly less than the thickness of the yarn with which it is to be used. WHAT WE CLAIM IS:

1. A guide for guiding a plurality of yarns to a seizing station, the guide defining a row of yarn-receiving formations with respective axes which are parallel to each other and are transverse to the length of the row, each formation being defined by a concave surface which extends around the axis, is interrupted at one side of the axis by a gap to admit the yarn to the formation and has a length (measured in a direction along the axis) greater than the mean distance of the surface from the axis, the guide further defining a plurality of substantially unobstructed tapered slots, one leading to each gap, and each slot having a narrower end at said gap and an open wider end remote from the gap.

the guide.

7. A method according to claim 6 wherein, during insertion of each yarn into the corresponding formation of the guide, relative movement of the yarn and guide in a direction longitudinally of the yarn occurs during said relative movement in a direction transverse to the length of the yarn.

8. In combination, a guide according to any one of claims I to 5 and a plurality of yarns wherein each yarn extends through and substantially fills a respective one of the yarn-receiving formations so that longitudinal movement of the yarn through the formation is impeded by friction between the yarn and the guide.

9. A method of presenting a row of yarn ends at a seizing station substantially as herein described with reference to the accompanying drawing.

10. A guide substantially as herein described with reference to and as illustrated in the accompanying drawing.