GB2189513A - Pile yarn selection in carpet looms - Google Patents

Abstract

A carpet loom has a series of horizontally extending pile yarn carriers (21) in which the ends of a series of yarns (4) are carried in longitudinally spaced positions and which are displaceable in their longitudinal direction to selected positions so that each can present a selected one of the yarns for drawing off by a gripper. Each carrier (21) or a driven member (26) for displacing the carrier has a series of engagement projections (22) spaced corresponding to the spacing between the yarns (4). The projections are selectively engageable by a solenoid-operated engagement member (28), so as to displace the carrier to position a selected yarn in register with the associated gripper. The solenoids are controlled by electronic programming means in accordance with sensors 23. In a second embodiment an engagement projection is pivotally mounted in the carrier and is pivoted into engagement with a selected protrusion on the displacing member. In a third embodiment the carrier is driven through a resilient coupling and is arrested at a selected position by a solenoid-actuated tooth engaging a selected one of a plurality of teeth on the carrier. <IMAGE>

Description

SPECIFICATION Pile yarn selection in carpet looms This invention concerns pile yarn selection in carpet looms, and to carpet looms having pile yarn selecting means adapted to carry out the method.

The invention more particularly relates to a pile yarn selection method, applicable to weaving of carpet, particularly but not exclu sively Axminster carpet, wherein carriers, in each of which ends of a plurality of yarns (e.g. of different colours) are substantially horizontally aligned, are adapted to be displaced substantially horizontally by a displacement motion to respective selected positions so that the selected yarns to be woven in the carpet fabric are presented at respective pre determined positions, for drawing off, for instance by means of respective grippers.

In the manufacture of such carpets, coloured pile yarns are selected, in accordance with a predetermined pattern. A required length is drawn off, is cut off from the supply and is then woven into the fabric.

Hitherto, it has been usual, in connection with the selection of the pile yarns, to make use of Jacquard mechanisms which control yarn carriers which are of strip-like form and are the smae in number as there are pile yarns required to be woven in transversely across the warp sheet and are aligned perpendicularly to the plane of the warps with predetermined spaces therebetween. The carriers are guided by suitable guides and are adapted to be moved vertically independently.

A lower half of each yarn carrier is so designed that ends of different coloured pile yarns to be used may penetrate therethrough with predetermined vertical spacings therebetween, and is provided with a clamping spring for preventing the yarns from unintentionally disengaging therefrom.

An upper half of each yarn carrier is formed with holes, the number of which is less by one than the number of coloured yarns to be used, with same vertical spacing therebetween as the coloured yarns, and respective movable stops are accommodated in the holes.

To the rear side of the yarn carriers is the Jacquard mechanism the function of which is to select, by displacement, movable stops, and each yarn carrier is adapted to be controlled by a respective longitudinal row in an operative Jacquard card which is operatively positioned on a cylinder, and forms a part of an endless or continuous chain of said cards.

Each Jacquard card is punched to control a number of needles which corresponds to the number of yarns, so that one of the needles may be moved forward, or none of them may be moved forward. Upon each successive operation of the Jacquard mechanism, the bar of the lifter moves upwards and engages with those movable stops which have been moved forwards by the needles, thereby to move the corresponding yarn carriers upwards. In this operation, since the bar stops its upwards movement at a constant position, the carriers always ascend to bring the selected yarns to a constant vertical position whereat they are subjected to subsequent processing, such as drawing off, cutting off and weaving into the carpet fabric.

If any particular row in the Jacquard card is fully punched so that the corresponding movable stops do not move forward, the corresponding yarn carrier(s) do not ascend, and as a result the uppermost coloured yarn(s) of such carrier(s) are selected.

After the drawing-off of the yarn, the bar descends, and a return or knock-off plate moves in a direction towards the Jacquard mechanism to return the movable stops to their inoperative or non-projecting positions ready for co-operating with the next successive Jacquard card to be brought to the operative position.

As described above, the coloured yarns are selected in accordance with the selected vertical positions to which the carriers are brought.

However, in this selecting device, there are many disadvantages. For instance, the mechanism is complicated and large. It is extremely noisy and the yarn to be woven may be misselected, which results in faulty patterns. Such disadvantages arise from the fact that the control of the vertical positions of the carriers is derived from the Jacquard cards. The Jacquard card operatively positioned on the reciprocating cylinder collides with the ends of the needles and this creates considerable collision noise.

The number of the carriers is the same as the number of pile yarns to be woven with the warps, and for example, more than one thousand carriers may be involved for a carpet of four metres in width. Therefore, the carriers are usually divided into eight groups, and one Jacquard mechanism is provided for each of the groups of the carriers. Therefore, when the cylinders move towards the stops, very loud noises and clatter are generated.

Further, co-operative and carefully synchronised operation of the Jacquard mechanism, the lift bars and the return plate is required in relation to the vertical movement of the carriers, and thus, if the timings of these operations are faulty, the selecting device does not operate properly.

Moreover, since each Jacquard card is made of paper it may become distorted or torn after prolonged use, in which case the needles cannot operate properly.

An object of the present Invention is, therefore, to provide a method wherein carriers, in which ends of a plurality of yarns are carried in spaced-apart disposition, are adapted to be moved to respective selected positions for of fering respective selected yarns to corresponding yarn grippers, in a manner which does not involve the use of Jacquard mechanisms, and in which the other disadvantages and difficulties discussed above are avoided.

The invention also provides means whereby this method may be carried into effect.

With this object in view, the present invention provides a pile yarn selecting method wherein substantially horizontally-extending carriers, in which ends of a plurality of yarns are carried in spaced-apart disposition, are adapted to be moved substantially horizontally to selected positions for offering respective selected yarns to corresponding yarn grippers, in which the respective pile yarns are drawnoff, characterised in that a plurality of engagement portions, which are horizontally spaced correspondingly to the spaces between the yarns and are formed on each carrier, or a member for displacing the carrier, are selected during horizontal movement of the carrier and a respective solenoid operates to move a respective engagement member towards the engagement portions and to engage said engagement member with the selected one of the respective engagement portions thereby to arrest the yarn carrier with a selected yarn positioned for gripping by a respective gripper.

The method may be carried out in such a way that each carrier is arrested during its forward movement from a starting position, or during return movement towards said starting position.

The invention further provides, in relation to carrying this method into effect, a carpet loom having pile yarn selecting means comprising a plurality of substantially horizontally extending carriers in each of which ends of a plurality of yarns are carried in spaced-apart disposition and which are adapted to be moved substantially horizontally by a correspondingly displaceable member, to respective selected horizontally-displaced positions to present selected said yarns for drawing off, characterised in that each said carrier, or the displaceable member, has a plurality of engagement portions which are spaced in correspondence with the spacings between the yarns and which are adapted selectively to be engaged during horizontal movement of the carrier by means of engagement members actuatable by solenoids, to engage with the selected engagement portions thereby to arrest the yarn carrier with a selected yarn positioned for gripping by a respective gripper.

As will be understood from the foregoing, in carrying the invention into effect, in a preferred way, the pile yarn selecting means comprises: (a) selecting or engagement portions which are substantially horizontally spaced corresponding to the horizontal spaces between the yarns and formed in the carriers or the displaceable member which member moves back and forth in reciprocating movement; (b) operating solenoids to move or cause movement of the respective engagement members towards their engagement portions, and effective to engage the engagement members with the respective selected engagement portions.

The engagement portions provided on the carriers or the displaceable member are in the form of a plurality of stages with same spacing therebetween as the horizontal spacing between the yarns in the carriers. The engagement portions are selected and the carriers are positioned at constant portions, so that the pile yarns corresponding to the engagement portions are always brought to constant positions.

When the carriers are moved vertically by the displaceable member the solenoids operate in relation to the selected engagement portions to move or initiate movement of the engagement members, e.g. by armatures of the solenoids or by air cylinders controlled by the solenoids so that the engagement members engage with the selected engagement portions of the displaceable member or the respective carriers.

When the engagement members engage with the engagement portions of the displaceable member or the carriers during forward movement of the member, the carriers are displaced from the engaged positions until the displaceable member reaches its forward or endmost position. When the member reaches its endmost position there are differences in the displaced positions of the various carriers, the yarns thus being selected in accordance with these differences, since each carrier will present only one of its yarns to respective gripper which draws the yarn off, for a tuft length to be severed therefrom and to be transferred to the shed to be woven with the fabric.

Similarly, in the case where the engagement members engage with the selected engagement portions of the carriers during return movement of the displaceable member the carriers stop and separate from the displaceable member which continues its downward movement, in their selected positions.

As will be understood from the above description the carriers can be stopped at accurately-selected horizontal dispositions by supplying appropriate electric signals to the solenoids to operate the latter.

Accordingly, in the present invention, since Jacquard cards are not used, mis-selection of the pile yarns, which can arise from damage of the Jacquard cards, is substantially eliminated and thus, errors do not occur in the pattern being woven. Since a Jacquard mechanism is essentially unnecessary, there is no noise such as that which arises from the collision and rotation of the cylinder.

Further, of course, the arrangement of the invention enables the solenoids to be controlled by means of programmable means, such as a computer, so that setting up of a pattern can be effected with the minimum of labour and inconvenience, and substantially instantaneously, as compared with the tedious and skilled work involved with Jacquards.

Moreover, since only one engagement member and only one solenoid are required for each yarn carrier, the mechanism can be simple. Since the horizontal movement of the lifter and the operation of the solenoid can commence without a time lag in accordance with the electric signals, accurate patterns can always be woven, The pile yarn selecting means can be embodied in various forms in which the engagement members are incorporated at different locations, for instance: (I) In an arrangement in which the engagement members are associated with the displaceable member which displaces the yarn carriers: In this case, the engagement members may be adapted to co-operate with the armatures of the respective solenoids fixed to the displaceable member.During the forward movement of the member, from an initial position, the solenoids operate to engage the selected engagement members with the engagement portions of the respective carriers after which the carriers continue to move and position the yarns to be selcted at the predetermined positions when the displaceable member reaches its endmost position.

In this form, the solenoids and the engagement members are constructed to form cooperative mechanisms and are set and fixed at the displaceable member. Therefore, the structure can be simple, and the engagement members can be controlled accurately.

(II) In an arrangement in which the engagement members are associated with the carriers In this case, during the forward movement of the displaceable member from its initial position, the solenoids operate to move the engagement members toward the displaceable member and engage them with the selected engagement portions, after which the carriers continue to move forward and eventually position the yarns to be selected at the predetermined positions when the displaceable member reaches its endmost position.

In this case, if the solenoids are fixed to the carriers, the accuracy of the control of the engagement members can be same as in the above described form, although the relationships of the positions are the reverse of those of the previously-described arrangement. Further, if the solenoids are fixed to a body of the device, the solenoids themselves do not move, so that the associated wiring work, in the manufacture of the device, can be extremely simple.

(III) in an arrangement in which the engagement members are associated with the body of the device In this case, during return movement of the displaceable member back towards its initial position, the solenoids fixed to the body of the device operate to move the engagement members toward the respective carriers to engage them with the selected engagement portions thereof. Thus when the carriers stop, the yarns required to be selected are disposed in predetermined positions ready for drawingoff and so on as mentioned above.

In this case, since the engagement members and the solenoids are associated with the body of the device, the advantages of both of the two previously-described forms can be obtained. Further, since it is required only to arrest the yarn carriers during their return movement, the whole device can be extremely simple.

In any of the above-discussed forms, the number of the engagement portions required to be selected may be zero. In this case, it is required only to design the mechanism so that first yarn end or the last end in each yarn carrier is disposed at the appropriate predetermined position, when the yarn carriers stop or are at rest, or when they reach their forward or rearward end positions as defined by corresponding movement of the displaceable member, fixed engagement means being provided for this purpose if desired.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic side view illustrating a first embodiment of the pile yarn selecting device of the invention; Figure 2 is a fragmentary view, comparable with Fig. 1, but illustrating a second embodiment; Figure 3 is a view comparable with Figs. 1 and 2 but illustrating a third embodiment.

The first embodiment of the invention which is illustrated in Fig. 1 as a schematic side view, comprises a pile yarn selecting device in which engagement members are associated with a displacement member, which serves to displace strip-form yarn carriers 21, of which there are a large number disposed side-byside, only one of these carriers being visible in the figure. The carriers 21 are longitudinally slidable in guides 7.

Each carrier 21 is provided, in its upper edge, with engagement portions in the form of equally-spaced sawtooth-like grooves 22, of which the number may be fewer by one than the number of tufting yarns 4 to be selected, these yarns 4 extending vertically through the carrier 21 at equal spaces along the carrier 21 to project therebelow for being taken up by a respective gripper (not shown) associated with the carrier.

A box member or casing 25 extends transversely across all of the yarn carriers 21, above the sawtooth-like grooves 22. This casing 25 is carried on the displacement member 24 which is adapted to move back and forth and is guided by a vertical column 26, an initial or starting position of the member 24, as illustrated, being defined by abutment of the member 24 against an end stop 27.

Sensors 23 are fixed to a body (not shown) of the yarn selecting device. The horizontal spacings of the sensors 23 correspond to the grooves 22 on the carriers 21, and the sensors 23 are adapted optically to read or indicate the positions of the successive grooves 22 when the casing 25 moves horizontally as indicated by the arrows 29.

The casing 25 is provided in its front wall with a long aperture (not visible) facing towards the carriers 21, and respective engagement members, in the form of teeth or pawls 28, project slidably from this aperture. Each such engagement tooth 28 has its projecting forward end complementarily shaped to interfit with the grooves 22 and is adapted to be extended by way of a respective solenoid (not visible) which is fixedly located in the casing 25.

Solenoids are used for rapid and accurate operation. If the width of each solenoid is larger than the width of the respective carrier 22, the solenoids may be arranged in staggered or spaced arrangement in the casing 25 and connected to their respective teeth or pawls by flexible rods or other linkages as maybe convenient or practicable.

The solenoids and the sensors 23 are connected to a signal generating device 35 disposed in the vicinity thereof by leads 36 and 37. The signal generating device 35 is adapted selectively to deliver signals to the solenoids in accordance with signals supplied from the sensors 23 so that the engagement teeth or pawls 28 will engage with respective selected ones of the grooves 22 whilst the casing 25 is moving in the forward direction; that is to say to the left as viewed in Fig. 1, whereafter the casing 25 carries with it the selected carriers 21, that is to say those carriers 21 which have been selected by entry of the respective tooth or pawl 28 into one of its grooves 22. This movement is continued until all of the carriers 21 have been brought to their selected positions, whereupon grippers (not shown) take up the respective selected yarns 4.Thereupon, the displacement member 24 moves back to its illustrated initial position, during which a return pusher 30 projecting rearwardly from the member 24 encounters return abutments 31 on the yarn carriers 24 and moves these back to their initial positions.

In this embodiment, the number of the grooves 22 in the carrier 21 may be fewer by one than the number of yarns 4, and the engagement tooth or pawl 28 will not be operated i.e. extended when the endmost yarn 4, being the left hand yarn 4 in the carrier 21, is to be selected. Accordingly, if the yarns 4 which are most frequently used are positioned as the endmost yarns in each carrier 21, the solenoids, the engagement teeth or pawls 28 and the carriers 21 operate less frequently so that wear and breakdown thereof are correspondingly reduced.

Of course, if desired, the number of the grooves 22 may be the same as the number of yarns 4.

Although only one casing 25 is provided above the carriers 21, in the illustrated case, the arrangement may of course by such that respective casings 25 may be provided both above and below the carriers 21, these casings operating to cause displacement of the alternate carriers 21. In this arrangement, it may not be necessary to space apart the solenoids and the corresponding casings can be small.

Referring now to Fig. 2, this illustrates, in a fragmentary schematic view, an embodiment of the pile yarn selecting device in which engagement members are associated with carriers 41 of the device.

Respective swing plates 48, which tend to swing down to the illustrated disengaged position by gravity or by spring are mounted by pivot pins 47 on the carriers 41. Spaced protrusions 45 are provided along one side of each displacement member 44, so as to face the carriers 41. During forward movement of the member 44, respective solenoids 49, which are fixed to a frame (not shown) of the device, operate to lift the swing plates 48 by respective armatures 51 thereof, so that projections 46 of these swing plates 48 enter between or move into engagement with the selected protrusions 45 of the displacement member 44, in grooves 42 therebetween.

When a projection 46 engages with a selected protrusion 45, the respective carrier 41 starts to move horizontally to the right in the drawing. In this operation, the swing plates 48 are prevented from swinging back down again by one or more side plates 50 which are disposed beneath the carriers 41, so that the projections 46 do not disengage from the protrusions 45. When the displacement member 44 moves back again (to the left in the drawing) and the carriers 41 have returned to their initial positions, the respective swing plates 48 swing down to project below the level of the side plates 50 and the projections 46 are able once again to disengage from the protrusions 45.

Fig. 3 illustrates, in a fragmentary schematic view, a carpet loom's pile yarn selecting device in which engagement members are associated with a hody of a device.

Yarn carriers 61 are disposed above and below a displacement member 64 and are adapted to be abutted and displaced into an initial position (to the right in the drawing) by the end of the member 64 abutting tongues 70 projecting therefrom.

Guide tubes 67 are fixed to a body (not shown) of the device, and engagement teeth or pawls, actuatable by solenoids (not shown) are movably accommodated in these tubes 67. During forward movement of the member 64 (to the left in Fig. 3), the respective solenoids (not shown) operate to extend and engage the engagement teeth or pawls 68 with selected grooves 62 of the vertically-aligned engagement groove series 62 formed on each of the carriers 61 which move with the member 64 by being resiliently connected thereto, e.g. by springs (not shown).

In each case, after an engagement rod 68 engages with the selected one of the corresponding engagement grooves 62, the member 64 continues to move, leaving the selected carrier 61 held stationary by its rod 68 so that the selected yarns are all brought to the necessary predetermined take-up positions ready for drawing-off by the grippers, severing, and introduction of the severed portion into the warp shed for weaving into the fabric. This having been achieved, the member 64 returns once again to the right hand position for the next selected yarns to be presented to the grippers, during the next cycle of operation.

In the illustrated embodiments, sensors 23 are used, for example, means for detecting the displaced position of the casing 25 or its equivalent, but of course other detecting means or methods may be employed. For example, the position of the casing, displacement member, yarn carrier or the like may be determined by calculating the moving speed of the casing or other relevant components of the device. Furthermore, in the illustrated cases, the solenoids are arranged to act directly upon their respective carriers, or upon the respective swing plates, but this is not essential, and the arrangement may be such that each solenoid controls a respective valve which opens and closes an air supply to a respective pneumatic cylinder or ram having an extensible piston rod which engages the carrier, swing plate or equivalent component.

Claims (17)

1. A pile yarn selection method wherein substantially horizontally extending carriers, in which ends of a plurality of yarns are carried in spaced-apart disposition, are movable substantially horizontally to alternative positions for offering selected yarns to corresponding yarn grippers which draw off the selected yarns, there being provided on each carrier or a member for displacing the carrier, at spacings correspondings to the spacings between the yarns, a plurality of engagement portions which are selected during said horizontal movement of the carrier, the selection of an engagement portion being determined by a solenoid operating to move a respective engagement member towards the engagement portions associated with each carrier so as to engage said engagement member with the selected engagement portion and thereby to arrest the yarn carrier with the selected yarn positioned for gripping by the associated gripper.

2. A method according to claim 1 wherein said engagement members are moved to arrest the carriers during forward movement of the carriers from a starting position.

3. A method according to claim 1 wherein said engagement members are moved to arrest the carriers during return movement of the carriers to a starting position after the carriers have been displaced away from that starting position.

4. A method according to any one of claims 1 to 3 wherein a further yarn selection position of the carriers is obtained in which the carriers are not arrested by their engagement members.

5. A method according to any one of the preceding claims wherein the positions of the carriers are sensed optically.

6. A carpet loom having pile yarn selection means comprising a plurality of substantially horizontally extending carriers :in each of which ends on a plurality of yarns are carried in spaced-apart dispositions and which are adapted to be moved substantially horizontally by a correspondingly displaceable member to respective selected displaced positions in order to present selected yarns for drawing off, each said carrier or its associated displaceable member having a plurality of engagement portions which are spaced in correspondence with the spacings between the yarns and which are adapted to be engaged selectively during said movement of the carrier by engagement members that are actuatable by solenoids, thereby to arrest the respective yarn carriers with a selected yarn positioned for gripping by their associated grippers.

7. A carpet loom according to claim 6 wherein the yarn selecting means of each carrier comprises selecting or engagement portions which are substantially horizontally spaced corresponding to the horizontal spaces between the yarns, said portions being formed in the carriers or the displaceable member, drive means for giving the displaceable member a reciprocating movement, and a plurality of solenoids for the respective carrier being operable to move or cause movement of their respective engagement members to engage said members with the selected engagement portions.

8. A carpet loom according to claim 7 wherein the engagement member for each carrier yarn selecting means is associated with he displaceable member and cooperates with a respective solenoid fixed to the displaceable member.

9. A carpet loom according to claim 7 wherein each engagement members is associated with a respective carrier and its solenoid is arrangement to operate in the forward movement of the displaceable member from its initial position to move the engagement member towards the displaceable member for engagement with a selected engagement portion on the displaceable member.

10. A carpet loom according to claim 9 wherein each engagement member is in the form of a panel pivoted on its carrier and movable by the associated solenoid to engage a toothed rack on the displaceable member.

11. A carpet loom according to claim 10 wherein the engagement member for each carrier is associated with a stationary body of the yarn selecting means and its solenoid is secured to said body for actuating the engagement member during the return movement of the displaceable member to an initial position to engage the members with a selected engagement portion on the carrier.

12. A carpet loom according to any one of claims 6 to 11 wherein each solenoid is arranged to move its engagement member towards the selected engagement portion during the forward displacement of the displacable member from an initial position.

13. A carpet loom according to any one of claims 6 to 11 wherein each solenoid is arranged to move its displacement member towards the selected engagement portion during the return movement of the displaceable member to an initial position.

14. A carpet loom according to any one of claims 6 to 13 wherein the carriers have a further yarn selecting position in which they remain at rest with the engagement portions unengaged by the engagement member.

15. A carpet loom according to any one of claims 6 to 13 wherein optical sensing means are provided for the displacements of the carriers.

16. A pile yarn selection method substantially as described herein with reference to the accompanying drawings.

17. A carpet loom provided with pile yarn selection means constructed and arranged substantially as described herein with reference to the accompanying drawings.