AU636588B2 - Method of and apparatus for manufacturing a pile fabric - Google Patents

Description

PATENTS

ACT

COMPLETE SPECIFICATION OR I G I NAL (FOR OFFICE USE) Class Int Class Application Number: Lodged: Complete Specification Lodged: Accepted: Pub] ished: 6 Priori ty Related Art: N. Name of App i cant .7 M-A; B- MT- Address of Appl icant 3.4 Bedford Row, London WCIR 4JH, United Kingdom Actual Inventor(s) Regina d.M s ey.and Th mas..Wa..t.r W.i.J] t Address for Service: PATENT ATTORNEY SERVICES 26 Ellingworth Parade, Box Hill, Victoria 3128 I i S' Complete specification for the invention entitled:

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l METHOD OF AND APPARATUS FOR MANUFACTURING A PILE FABRIC It The following statement is a full description of this invention, including the best method of performing it known to us The present invention relates to the manufacture of a pile fabric by implanting tuft-forming lengths of yarn in a layer of an adhesive on a pre-formed web. An example of the manufacture of pile fabrics by such a method is described in GB-1422524A, published 28th January 1976.

In the method described in the aforesaid published specification, a row of yarn ends is presented at a seizing station, grippers are advanced to grip all of the yarn ends of the row and are retracted to draw concurrently the required lengths of yarn from a source.

The required lengths of yarn, still held by the grippers, are severed from the supplies of yarn in the source and are then moved to a position over a slot defined between a pair of tuft-control members. A web bearing a layer of adhesive is supported on the circumferential surface of a roll below the slot. Prior to reaching the slot, the advhesive is heated so that it is in a tacky condition :r .directly beneath the slot. A blade having a length 20 substantially equal to that of the slot is moved downwardly through the slot, pushing mid-portions of the lengths of yarn through the slot into the layer of adhesive, leaving end portions of each length of yarn in the slot. After the blade has been withdrawn from the slot, the row of newly implanted tufts is advanced from the slot, the end portions of the tufts being pushed past the control member which lies at the downstream boundary of the slot. This control member then prevents the end portions returning to obstruct the slot.

In a case where different rows of tufts are required to contain differently coloured tufts or coloured tufts arranged in a different order along the row, the source of yarn used in the method described in GB-1422524A is required to include a number of sets of yarns (generally called packages), each set including a number of yarns equal to the number of tufts in a row.

The source of yarn generally includes a number of spools which are connected together in a chain. On each spool there is wound a number of yarns equal to the number of tufts in a row. The number of packages or spools required depends upon the pattern to be produced on the web by the coloured tufts. The source of yarn may comprise more than 100 spools.

A chain of spools is a suitable source of yarn for the manufacture of long pieces of pile fabric, for example, having a length of many metres. However, the use of the source of yarn proposed in GB-1422524A, that is a chain of spools, is uneconomic for the production of a small quantity of a pile fabric, for example, a piece having a length of only one or two metres. Short pieces of pile fabric are required as samples for inspection by 20 potential customers and by designers of pile fabrics.

For example, a designer may require a number of samples of a particular design, the samples differing in respect of the colours used. There is also a requirement for small quantities of pile fabrics which have a pattern specific to a single customer or to a single premises where the pile fabric is to be used. For example, there may be a requirement for several pieces of carpet which bear a company logo.

According to a first aspct of the preentinvention, there is provided a method _ofoacturing a pile fabric wherein 'of tuft-forming yarn are appli~d- entially to a pre-formed, flexible web to '~build ap stcp-by-step a rw of tufts on the web and I13I I r 1313 t i l i

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<jI 2 3a According to a first aspect of the present invention there is provided a method of manufacturing a pile fabric wherein lengths of tuft-forming yarn are applied sequentially to a pre-formed, flexible web bearing a layer of adhesive, the lengths of yarn being embedded in the layer of adhesive to build-up step-by-step a row of tufts on the web.

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i L f 4 wherein-thc tufts of tho rw prg tached to th web.

The lengths of yarn to be incorporated in a single row can be selected sequentially from a source of yarn.

It is not necessary to provide a spool for each row in the pattern. The source of yarn may incorporate only a single yarn of each of the colours which is to be incorporated in the pile fabric.

In carrying out a method in accordance with the first aspect of the invention, the pitch of the tufts along the row and the pitch at which yarn ends are presented by the source of yarn can differ. Accordingly, samples having respective different pitches along the row can be produced using the same source of yarn.

In performance of a method in accordance with the first aspect of the present invention, more than one tuft-forming length of yarn may be introduced into a single row on the web concurrently. However, the tufts of the row are not all transferred concurrently to the '(ili °web. Typically, successive tufts will be implanted at successive positions along the row. Implanting may take 20 place concurrently at several, spaced positions along the row.

.Oa o rOW.

O° ~In the method disclosed in GB-1422524A, the ends of the yarns are presented by the source in a row and the pitch of the yarns along the row is the same as the pitch of the tufts in each row attached to the web. This facilitates transfer of a complete row of tuft-forming lengths of yarn concurrently from the source to the web.

However, in order to change the pitch of the tufts in the rows which are attached to the web, it is necessary to change the source of yarn to present the- yarn ends at a new pitch. In a method in accordance with the present Sinvention, the pitch at which yarn ends are presented by ,rt the source from which the tuft-forming lengths of yarn are drawn and the pitch at which tufts are positioned in each row on the web can differ. The yarn ends may be presented by the source in respective positions which are spaced relatively far apart. This facilitates preparation of the source of yarn. Furthermore, the pitch at which the yarn ends are presented by the source does not determine the pitch of the tufts in each row attached to the web.

In performance of a method in accordance with the first aspect of the present invention, each tuft-forming length of yarn is preferably attached to the web by means of a layer of a hot-melt adhesive on the web. In this case, the tuft-forming lengths of yarn are embedded sequentially in the layer of adhesive and when a length of yarn is embedded in the layer of adhesive at one position along the row, the adhesive is heated at a further position along the row. Thus, the adhesive is preferably heated sequentially at successive positions along the row. The adhesive at each position may therefore be heated for only a brief period immediately prior to embedding a length of yarn at that position.

S Heating means is preferably traversed along a path corresponding to the position to be occupied by a row of tufts.

Each tuft-forming length of yarn is preferably applied to the web through an aperture defined by tuftcontrol means which surrounds the tuft formed by said length. The tuft may be a single tuft but is preferably a double tuft, formed by bending the length of yarn substantially into a U-shape. By surrounding the tuft, the tuft-control means limits movement of.-the tuft in all directions other than towards and away from the web.

After a length of yarn has been applied to the web, elements of the tuft-control means are preferably moved 6 relative to the web whilst maintaining the separation between said elements and the web substantially constant, the movement being such as to release from the aperture the tuft formed by that length of yarn. The movement of the elements of the tuft-control means to release the tuft from the aperture is preferably followed by an opposite movement of those elements.

According to a second aspect of the invention, there is provided apparatus for carrying out the method of the invention, the apparatus being operative to apply tuft-forming lengths of yarn to a web at a tuft attaching station, the apparatus comprising a support for the web at the attaching station, guide means for guiding the web along a path to the attaching station, tuft-control means for controlling the attitude of a tuft attached to the web at the attaching station and transfer means for transferring the tuft-forming lengths of yarn from a source thereof to the web at the attaching station, the guide means including means for guiding a transfer member of the transfer oo means for movement relative to the web in a direction transverse S to a plane which is perpendicular to a face of the support which bears the web at the attaching station and which is parallel to said path at the attaching station, drive means being provided for causing relative movement of the transfer member and the web in said direction.

Apparatus in accordance with the second aspect of the invention is especially although not essentially suitable for use in the manufacture of a pile fabric by attaching lengths of 7 6a yarn to a web to form rows of tufts with the length of each row extending in said direction. If the length of the web is taken to be that dimension which extends along the path of the web through the attaching station, then said direction is a direction across the web.

4 C o 2 4*2b 7 The tuft-control means also preferably includes an element which is movable relative to the web in said direction. The drive means is preferably arranged for moving said element of the tuft-control means in said direction.

Accordinq- to a third aspect of the invention, thr is provided apparatus for applying tuft-forming lengt of yarn to a web at a tuft attaching station, wher the apparatus comprises a support for the at the attaching station, guide means for guidi the web along a path through the attaching statio tuft-control means for controlling the attitude a tuft attached to the web at the attaching sta 'on, a source of yarn which includes holding mean for holding a number of yarn ends in a row and ftinsfer means suitable for gripping a selected on of said yarn ends and drawing a length of one ya from the source whilst leaving the other yarn e of the row undisturbed, the transfer means being arranged for transferring the length of yarn drawn off from the seurce to the web at the attaching station.

An example of apparatus embodying both the second a|nd the third aIpetc of the invention and which is used in a method according to the first aspect of the invention will now be described, with reference to the accompanying drawings, wherein:- FIGURE 1 shows a perspective view of parts of the apparatus, including certain parts represented in Figure 2, and wherein FIGURE 2 shows diagrammatically certain parts of the apparatus, as viewed in a direction along a row of tufts which are applied to a web.

The apparatus illustrated in the drawings comprises a support 10 for supporting a flexible web 11 at an attaching station 12 where pile tufts are applied 7^^ 8 to the web. The web is typically a fibrous web and may be of woven or non-woven construction. The web includes on one of its faces a layer of a hot-melt adhesive. At the attaching station, an opposite face of the web bears on the support 10 and the adhesive layer faces away from the support. For convenience of illustration, the web is shown in the drawings with the adhesive layer facing upwardly at the attaching station.

The apparatus includes guide means for guiding the web 11 from a bulk supply 13 over a draw-off roll 14 and via an accumulator 15 to the support 10. The guide means is also arranged for drawing the web from the support and delivering the web from the apparatus at a delivery station 16. For drawing the web from the support 10, the guide means typically includes a pair of rolls 17 and 12 between which the web passes and which nip the web. One or both of these rolls is turned step-wise by drive means of the apparatus (not shown) and the roll 17, which engages that face of the web which is spaced from the adhesive layer, may be provided with spikes or other means for preventing slip of the web relative to the roll.

The support 10 has a flat surface 19 which bears the web 11 at the attaching station. The surface 19 is elongated and is arranged with its length extending transversely of the direction of movement of the web through the attaching station. The length of the surface 19 is somewhat greater than the width of the widest web intended to be used in the apparatus. Upstream and downstream of the flat surface 19, the support 10 has S 30 respective convex surfaces on which the web slides towards and away from the surface 19.

At the attaching station 12, there is provided tuft-control means for controlling the attitude of a tuft 4 C 9 attached to the web at the attaching station. The tuftcontrol means includes upstream and downstream tuf tcontrol members 20 and 21 respectively. These control members are spaced apart in the direction of travel of the web 11 through the attaching station to define between them a slot 22. In the example illustrated, those faces of the members 20 and 21 which define opposite boundaries of the slot 22 are flat, mutually parallel and are perpendicular to the filat support surface 19. The lengths of these surfaces are at least approximately equal to the length of the flat surface 19.

The upstream control member 20 is fixed with respect to the support 10 and is spaced upwardly from the flat surface 19 by a distance which is considerably shorter than the length of each tuft which is applied to the web 11 by the apparatus. Preferably, the spacing between the flat ,:apport surface 19 and the upstream control member does not exceed one half of the length of each tuft, that is the distance from the web 11 to the tip of the tuft, when the tuft is in an upright attitude.

The downstream control member 21 includes a main portion of generally plate-like form and which, in the example illustrated, is horizontal. At a margin of this t Q main portion which is adjacent to the slot 22, there is V provided a flange 23 which depends from the main portion 425 of the control member towards the support 10. The flange 23 approaches as closely to the support surface 19 as does the upstream control member 20. At least the tip of the flange 23 which is nearest to the support surface 19 4 is narrow. That is to say, the dimension of the flange which extends in the direction of travel of the web 11 through the attaching sta~tion is no greater than the width of the slot 22. Preferably, this dimension of the flange is less than one half of the width of the slot.

t x t The support 10 and the upstream control member are mounted in respective fixed positions relative to a frame 24 of the apparatus. The downstream control member 21 is guided for reciprocation relative to the frame 24 in a direction such that the flange 23 moves towards and away from the flat support surface 19. The flange can be raised from a position in which it is spaced from the surf ace 19 by a distance less than one half of the length of a tuft to a position in which it is spaced from the support surface 19 by a distance exceeding the height of each tuft. The drive means of the apparatus includes piston and cylinder units, one of which is shown at for raising and lowering the control member 21 relative to the frame 24. The downstream control member may be guided for movement relative to the frame along a rectilinear path or along a curved path. Furthermore, the arrangement may be such that movement of the flange 23 is greater than is the movement of other parts of the control member. The control member may be rocked upwardly about an axis which is fixed with respect to the frame 24. The rocking axis may pass through the control member 21.

The tuft-control means further comprises a dividing member 26 which divides the slot 22 into opposite end portions and an intermediate portion lying between -the end portions of the slot. The intermediate portion is a minor portion of the slot. Preferably, that dimension of the intermediate portion which extends along the slot Vdoes not exceed twice the width of the slot. The intermediate portion of the slot constitutes an aperture defined collectively by the tuft-control. members 20 and 21 and the dividing member 26.

The dividing member 26 rests on an upwardly facing surface of the upstream control member 20 and has a pair at t 11 of limbs 27 and 28 which depend into the slot 22. These limbs are spaced apart in a direction along the slot and defind opposite boundaries of the aperture. The limbs 27 and 28 are spaced from the flat support surface 19 by a distance considerably less than the length of a tuft so that the limbs overlap with a free end portion of a tuft, when that tuft occupies the aparture defined by the tuftcontrol means. It will be appreciated that the control members 20 and 21 and the limbs 27 and 28 collectively surround a tuft disposed in the aperture and constrain that tuft to have an upstanding relation with respect to that part of the web 11 which rests on the flat support surface 19.

The apparatus further comprises a source 29 of yarn which is to be used for forming the tufts supplied to the web 11. The source comprises a number of different yarns, for example, yarns of different colours or differing from one another in respect of other characteristics, and is arranged for presenting respective end portions of these yarns in a row or other pre-determined array. In the example illustrated, the source 29 presents the yarn ends in a single, rectilinear row. The length of this row is parallel to the length of the slot 22 and the yarn ends lie in respective positions spaced somewhat from the attaching station in a direction which is at least approximately parallel to the flat support surface 19.

The source 29 of yarn includes holding means for holding the yarn end portions in respective predetermined positions. The holding means illustrated by way of example comprises carrier 31 defining a number of passageways one for each yarn. In alignment with each passageway, there is provided a spring which bears on the yarn to prevent inadvertent longitudinal movement of the lit CI (til _14 yarn, in particular, spring-back of the yarn when a length of yarn is cut from the supply.

Preferably, several passageways are provided in a common carrier. However, it is preferred that the passageways are not all provided in a single carrier.

Furthermore, it would be within the scope of the invention to form each passageway in a carrier which carries a single yarn only. The preferred number of carriers is selected according to the number of yarns.

There may, for example, be from ten to twenty yarns carried by each carrier and two or more carriers. The number of passageways provided by the carrier or carriers will depend upon the number of different yarns which are required to be available for use by the apparatus.

Each of the carriers 31 is mounted for movement relative to the frame 24 in two mutually perpendicular directions, namely, a direction parallel to the length of the slot 22 and a direction towards and away from the attaching station. The drive means of the apparatus includes means for reciprocating the carrier in these directions. Preferably, each carrier can be moved towards and away from the attaching station independently ir of the other carriers. A pneumatic piston and cylinder tit 1 unit is a suitable means for reciprocating the carrier in this direction. The carriers may be movable together in a direction along the slot 22. Suitable drive means for reciprocating the carriers in this direction comprises a toothed belt, a sprocket and a stepper motor. The maximum stroke of the carriers in a direction parallel to the length of the slot 22 is approximately equal to the length of the slot. The permitted stroke'of the carriers towards and away from the attaching station is relatively short, for example, within the range 5 The bulk supply of yarns may be arranged in the c I I L: I I 13 source 29 in any convenient manner. For example, the yarns may be wound into cones and the cones supported by a known creel (not shown).

The apparatus further comprises transfer means for transferrring tuft-forming lengths of yarn from the source 29 to the web 11 at the attoching station. The transfer means includes a gripper 32 mounted on a carriage 33 for reciprocation relative to the carriage between a retracted position illustrated in the drawings, in which the gripper lies at that side of the slot 22 which is remote from the source 29 of yarn and a projected position in which the gripper extends across the slot 22 to overlie the downstream control member 21.

A piston and cylinder unit 34 is provided on the carriage 33 to reciprocate the gripper. A further piston and cylinder unit 35 is provided for opening and closing the gripper. Additionally, a spring may be provided for either opening or closing the gripper.

The width of the gripper 32, that is the dimension which extends along the slot 22, is somewhat less than twice the pitch of the yarn ends in the row presented by the source 29. The width of the gripper is, however, considerably greater than the thickness of an rIr uncompressed yarn. When the gripper is moved to its projected position and is opened and an appropriate one of the carriers 31 is moved to the limit of its travel towards the attaching station, an end portion of a yarn is received between the jaws of the gripper. Provided that the gripper is positioned with its longitudinal centre line at least approximately aligned with a single yarn end, the gripper can be closed to seize that yarn end without disturbing either of the adjacent yarn ends.

Once the gripper has been closed, the carrier is moved away from the attaching station so that a length of yarn a a 14 is drawn from the source through the carrier.

The apparatus further comprises severing means for severing a length of yarn which has been drawn through a carrier 31 by movement of the carrier away from the attaching station.

The severing means comprises an anvil 36 which lies below the level of the carrier 31 and is spaced somewhat from the carrier in a direction towards the attaching station. When the carrier moves away from the attaching station, a yarn which has been seized by the gripper 32 is drawn across the anvil 36. The particular form of anvil illustrated is a roll and is mounted for free rotation about an axis which is fixed with respect to the yarn carrier 31. The anvil extends along the entire length of the rows of yarn ends presented by the source 29. Thus, the length of the anvil is approximately equal to the length of the support The severing means further comprises a cutting knife 37 which is mounted in a housing 38 for reciprocation towards and away from the anvil 36 along a path such that a cutting edge of the knife moves through a yarn which has been drawn across the anvil. Since, in It 1149 the example illustrated, the yarn is drawn across the top ii I of the anvil, the knife can be retracted to a position spaced upwardly from the anvil. That dimension of the cutting edge of the knife 37 which extends in a direction along the anvil is short, relative to the length of the anvil. For example, the cutting edge of the knife may have a length equal to the width of the gripper 32. A piston and cylinder unit 39 is provided for reciprocating the knife 37 relative to its housing 38. The path along which the cutting edge of the knife is reciprocated is offset slightly from the axis of the anvil 36 so that each impact of the knife on the anvil tends to turn the Itg I~il anvil about its axis. This distributes wear over the surface of the anvil.

The transfer means further comprises a finger which is mounted in a housing 41 for reciprocation along a rectilinear path towards and away from the flat support surface 19. A piston and cylinder unit 43 is provided for reciprocating the finger relative to its housing 41.

The path along which the finger is reciprocated extends through the intermediate portion of the slot 22. The arrangement is such that the finger can travel down substantially to the layer of adhesive on the web 11 which is resting on the flat support surface 19 and that the finger can be retracted to a level above the path along which the gripper 32 moves.

The carriage 33 is guided for reciprocation relative to the frame 24 along a path which is parallel to the length of the slot 22. Drive means is provided for moving the carriage to the selected position along its path of travel. A ball screw and stepper motor are a suitable form of drive means for reciprocating the carriage. The gripper 32 is constrained to move with the carriage by a pair of guide bars 43 which are fixed with respect to the carriage and on which the gripper slides between its projected and retracted positions. The dividing member 26 also is fixed on the carriage. The housings 38 and 41 are rigidly connected with the carriage by a bracket 44 so that the knife 37 and the finger 40 also reciprocate with the carriage.

There is also mounted on the carriage 33 by means of the bracket 44 a source 45 of hot air. The source may comprise a fan and an electrical heating element for heating air driven by the fan into a duct 46. The duct is arranged to lead the hot air to a position in the slot 22 immediately adjacent to the dividing member 26 and to direct the hot air onto the layer of hot melt adhesive on the web 11. The source 45 is arranged to supply air at a temperature such that the jet of hot air which impinges on the layer of adhesive reduces the viscosity of the adhesive sufficiently to render the adhesive tacky and to facilitate embedding of a length of yarn in the adhesive immediately after the adhesive has been heated.

The apparatus also includes control means (not illustrated) for controlling operation of the drive means of the apparatus. Typically, the control means includes a programmable logic controller which provides electrical output signals to valves controlling operation of the several piston and cylinder units of the apparatus. A micro-processor may be used to apply control information to the controller and to the several stepper motors of the apparatus.

In use of the apparatus, the carriage 33 is traversed to position the duct 46 for heating of the adhesive layer at a position where a tuft is to be embedded in the adhesive layer, for example, a position at one end of a row of tufts which is to be attached to the web 11. The carriers 31 are moved in a direction along the slot 22 to position a selected yarn end in alignment with the gripper 32. The carrier is also advanced so that the selected yarn end moves to a position when it can be seized by the jaws of the gripper. The gripper 32 is opened and is moved to its projected position and is then closed to seize an end portion of the selected yarn. The carrier 31 moves away from the attaching station to draw off the required length of yarn and the knife 37 is then' driven down to the anvil 36 to sever the length of yarn from the bulk supply. The gripper 32 then moves to its retracted position and the carriage 33 is moved to bring the X t A p. a .tg. ~I~fl~C tV~ 'W~ 17 aperture defined by the tuft-control means to a position directly above the position where the layer of adhesive has been heated.

When the gripper 32 moves into its retracted position, it draws the severed length of yarn across the slot 22 until a mid-portion of the length of &rn lies directly over the aperture defined by the tuft-control means. The gripper is then opened and the finger 40 is moved towards the support 10 to engage the mid-portion of the length of yarn and to push that mid-portion through the aperture into the layer of adhesive on the web 11.

Opposite end portions of the length of yarn are drawn into the aperture but remain therein, surrounded by the surfaces of the tuft-control means. The finger 40 is withdrawn from the aperture, leaving the mid-portion of the length of yarn embedded in the layer of adhesive and the opposite end portions of the length of yarn forming a double tuft. The carriage 33 is then moved in a direction along the slot 22 toward what will be an opposite end of the row of tufts to be attached to the web. The carriage is moved sufficiently far for the :1 ~.:limbs 27 and 28 both to move out of engagement with the newly attached double tuft. Movement of the carriage is 4 then reversed so that one or other of the limbs 27 and 28 engages the newly attached tuft. Such engagement either holds the newly attached tuft in an upright attitude or bends the newly attached tuft somewhat.

During movement of one length of yarn through the aperture of the tuft-control means into the layer of adhesive on the web at a f irst position, the layer of adhesive has been heated at an immediately adjacent position by air delivered from the duct 46. When the carriage 33 is returned along the slot, after having released the newly attached tuft from the aperture of the -r 18 tuft-control means, that aperture is positioned above the heated adhesive, ready to receive a further length of yarn. The procedure is repeated until a row of tufts has been completed.

When a row of tufts has been completed, the flange 23 of the downstream guide member 21 is raised away from the flat support surface 19 until it is clear of the newly attached tufts. The web 11 is then advanced through the attaching station to move the row of newly attached tufts past the flange 23 and the flange is subsequently lowered to hold the newly attached tufts away from the slot 22.

The web 11 may be advanced to move a newly attached row of tufts past the flange 23 and then reversed to position directly beneath the slot 22 a region of the web at which the next row of tufts is to be attached.

Furthermore, movement of the flange 23 may include a component towards and away from the upstream control member 20, in addition to the component of movement in a direction towards and away from the support surface 19.

If required, one or more additional carriages corresponding to the carriage 33 may be incorporated in "the apparatus. Each of the additional carriages would be provided with a respective knife, finger, gripper and dividing member so that a number of tuft-forming lengths of yarn equal to the number of fingers 40 can be applied concurrently to the web 11. Furthermore, there may be a i common carriage for several grippers and associated parts. In a case where several grippers are provided, it may be necessary to duplicate each colour of yarn in the source 29. In a case where a single gripper is provided, that gripper can seize any selected yarn presented by the source.

The pitch of tufts within a row can be varied from It 4r 4 rITr ~x-il- il~WJ~Ys9r4 19 one row to another by varying the instruction given to the control means so that the movements of the carriage 33 are varied. The pitch of the tufts in a row is not determined by the pitch at which yarn ends are presented by the source 29. Typically, the pitch of the yarn ends presented by the source will be a plurality of times the pitch of tufts along a row.

The flat spport surface 19 preferably extends from the slot 22 in the downstream direction a distance which exceeds the pitch of successive rows along the web, but which is not more than eight times and is preferably not more than five times the pitch of successive row along the web.

After the hot air duct 46 moves away from a position where the layer of adhesive has been heated, the adhesive at that position cools. Accordingly, the viscosity of the adhesive increases after the mid-portion of a length of yarn has been embedded in the adhesive.

The viscosity continues to increase as the finger 40 is withdrawn from the yarn and during movement of the dividing member 26 along the slot 22 to release the tuft from the aperture defined by the tuft-control means.

o The spacing of the limbs 27 and 28 from the flat a a o support surface 19 is such that the tufts can escape from the aperture defined by the tuft-control means through the gap between one or other of these limbs and the web 11. The separation between the flange 23 and the surface 19, when the flange is in its lowered position, is considerably smaller so that escape of tufts from the aperture defined by the tuft-control means "hrough the gap between the flange 23 and the web 1. 1 -vented, until the flange 23 is moved away from the u When the flange 23 is in its normal position, the fE is spaced from the web 11 by a distance which does not txceed twice ~mc: the thickness of each tuft, when in an uncompressed condition. Preferably, the flange is spaced no more than 2mm from the layer of adhesive.

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Claims (24)

1. A method of manufacturing a pile fabric wherein lengths of tuft-forming yarn are applied sequentially to a pre-formed, flexible web bearing a layer of adhesive, the lengths of yarn being embedded in the layer of adhesive to build-up step-by-step a row of tufts on the web.

2. A method according to Claim 1 wherein mutually adjacent lengths of yarn are applied sequentially to the web.

3. A method according to Claim 1 or Claim 2 wherein one row is completed before tufts of an adjacent row are applied to the web.

4. A method according to any one of the preceding Claims wherein each tuft-forming length of yarn is transferred from a source of yarn to a tuft-attaching station by means of a gripper and wherein the gripper is moved along the row to successive position at which successive tufts are to be incorporated in the row.

A method according to any one of the preceding Claims wherein said adhesive is a hot melt adhesive, when a length of yarn is embedded in the layer of adhesive at one position along the row, the adhesive is heated at a further position along the row and wherein the adhesive is subsequently heated at still further positions along the row in sequence.

6. A method according to Claim 5 wherein heating means for heating the layer of adhesive is traversed along a path corresponding to the position to be occupied by a row of tufts.

7. A method according to any one of the preceding Claims wherein each tuft-forming length of yarn is applied to the web through an aperture defined by tuft-control means which surrounds the tuft formed by said length sufficiently closely to contact the yarn during application of the tuft-forming length of yarn to the web.

8. A method according to Claim 7 wherein, after a tuft-forming length of yarn has been applied to the web, elements of the tuft-control means are moved relative to the web to release from said aperture the tuft formed by said length.

9. A method according to Claim 8 wherein, after the tuft has been released from the aperture, one of said elements of the tuft-control means is moved in a direction along the row into engagement with the tuft to hold the tuft away from a position where an adjacent tuft is to be added to the row.

A method according to any one of Claims 7 to 9 wherein, after one row of tufts has been built up on the web, a tuft-control member which lies between that row and an adjacent, previously applied row, is moved relative to the web to increase the separation between the web and that member to a value exceeding the height of the tufts, is moved relative to the web in a direction away from said previously applied row, is then tl moved relative to the web to decrease the separation between S said member and the web and is then moved relative to the web in rI.. I a direction towards the previously applied row up to said one row.

11. A method according to Claim 8 or Claim 9 wherein the separation between said elements of the tuft-control means and the web is maintained substantially constant during movement of said elements to release the tuft from the aperture. 23

12. A method according to Claim 8 wherein the movement of said elements is followed by an opposite movement of the elements.

13. A method according to any one of Claims 1 to 6 wherein, during attachment of the tufts of one row to the web, tufts of that row are separated from tufts of an adjacent row by a tuft-control member which overlaps with at least onc half of the length of each tuft.

14. A method according to Claim 13 wherein the tuft-control member is spaced from the web by a distance which does not exceed twice the thickness of the uncompressed tuft.

A method of manufacturing a pile fabric substantially as herein described with reference to the accompanying drawings.

16. Apparatus for carrying out the method as claimed in any one of the preceding claims, the apparatus being operative to apply tuft-forming lengths of yarn to a web at a tuft-attaching station, the apparatus comprising a support for the web at the attaching station, guide means for guiding the web along a path through -the attaching station, -tuft-control means for controlling the attitude of a tuft attached to the web at the attaching station and -transfer means for transferring successive tuft-forming lengths of yarn from a source thereof to the web at the attaching station, the guide means including means for guiding a transfer member of the transfer means for movement relative to the web in a direction transverse to a plane which is perpendicular to a face of the support which bears the web at the attaching station and which is parallel to said path at -the attaching station, drive means being provided for causing relative movement of the transfer member and the web in said 242 direction.

17. Apparatus according to Claim 16 wherein the tuft-control means also includes an element which is movable relative to the web in said direction.

18. Apparatus according to Claim 16 or Claim 17 wherein the tuft-control means defines an aperture and wherein the transfer member is movable through the aperture towards and away from the support.

19. Apparatus according to Claim 18 wherein the tuft-control means comprises a pair of control members which are spaced apart to define between them a slot and a dividing member which divides the slot transversely of its length and which is movable along the slot.

Apparatus according to Claim 19 wherein at least one of said control members is movable towards and away from the support.

21. Apparatus according to any one of Claims 16 to 18 wherein *jthe tuft-control means includes a pair of control members which are spaced apart to define between them a slot, one of these '0 control members lies between the slot and a previously implanted row of -tufts and this control member approaches -the adhesive layer so closely that the tufts cannot escape from the slot past that control member.

22. Apparatus according to any one of Claims 16 to 21 further comprising a source of yarn which includes holding means for holding a number of yarn ends in a row and transfer means suitable for gripping a selected one of said yarn ends and _d---,-rawing a length of one yarn from the source whilst leaving the ^7 i other yarn ends of the row undisturbed.

23. Apparatus according to Claim 22 wherein the drive means is arranged for moving the transfer member in said direction relative to the web to predetermined positions in sequence and wherein the pitch of said predetermined positions differs from the pitch at which the holding means holds the yarn ends in the row.

24. Apparatus substantially as herein described with reference to the accompanying drawings. Dated this 17th day of August, 1992 PATENT ATTORNEY SERVICES Attorneys for SELLERS MICAS LIMITED 4, i S S I Ij S" J' 'i i f A f r ^y