GB2218118A - Yarn selection in carpet looms - Google Patents

Abstract

A colour selector for a carpet loom in which grippers transfer selected tufts of yarn into a position in which they can be trapped between the weft and warp threads comprises a computer memory storage unit which issues programmed signals causing engagement between a reciprocating lifting bar 18 and a plurality of selectors 2 connected to yarn carriers to raise the selectors a particular distance. As shown solenoids 10 or pneumatic cylinders act through cables 8 to extend a peg 4 to engage a selected station 24 on the lifting bar. Alternatively a single peg on the lifting bar engages a selected one of stations cut in the selector. In a third embodiment push pins on the lifting bar push bolt pegs on the selector to engage another part of the lifting bar. <IMAGE>

Description

IMPROVEMENTS IN AtiD RELATING TO CARPET LOOMS The invention relates to carpet looms of the type in which grippers transfer selected tufts of yarn from yarn carriers to a position in which the tufts can be trapped between the weft and the warp threads with each pick of the loom. For the weaving of a patterned carpet such looms are equipped with a colour selection system which is connected to the drive motion of the loom so as to work in synchronisation with each loom cycle. The different coloured yarns are supplied to the grippers on a series of vertical yarn carriers each usually carrying eight but possibly tweleve or sixteen different yarns, vertically arranged on the carrier.

There are a large number of carriers arranged across the width of the loom. For example, a 12ft wide loom will have 1008 carriers across its width. With each carpet weaving cycle of the loom, each carrier is individually raised into a position to supply the respective gripper with the appropriately coloured yarn for that particular row of the carpet pattern. Once the grippers have gripped the yarns a cutting blade then severs each yarn from its station in the carrier leaving a tuft in the jaws of the gripper for insertion between the weft and the warp threads.

Each of the yarn carriers is connected to a selector blade. These blades are provided with means to selectively engage a lifting bar running across the width of the loom which is raised by a fixed stroke at each cycle of the loom. The lifting bar contacts and engages the engagement means of each of the selectors at a particular position of the lifting stoke, thereby rousing each of the selector blades until the lifting bar reaches the top of its stroke. The point in the lifting stroke at which the lifting bar engages each selector is determined by the colour selection system which thus determines how far each selector blade and hence each connected yarn carrier is raised with each loom cycle. Such a loom will hereinafter be referred to.

as a gripper carpet loom of the type described.

Hitherto the movement of the selectors and the yarn carriers and hence colour selection has been mechanically controlled. One commonly used mechanical colour selection system for moving the yarn carriers into the correct position is the Jacquard. In this device the lifting bar engagement means comprises a plurality of horizontal pegs fitted into the selector blades the pegs being equally spaced above one another, the number of pegs always being one less than the number of yarns in the carrier. Which particular peg is pushed out of each selector to engage the lifting bar is determined by a loop of cards which are punched with holes in a pattern corresponding to the desired carpet pattern. The cards are arranged in horizontal rows, each row representing a single tuft row of the weave.

The loops of cards are arranged within the Jacquard such that each row is forced against metal plates which by means of a series of spring loaded needles forces the appropriate peg out of each selector where a hole is absent on each row of the card. Thus the carpet pattern is transferred from the punched cards to the selectors so that the carriers are moved into position in accordance with the pattern.

A major disadvantage of the mechanical Jacquard colour selection system is that the carpet pattern must be transferred from graphed design paper or point paper to the punched cards manually by an operative who sets punch pegs within a card stamping machine to match each row of pattern across the width of the loom. Such a process is very time consuming. For example, for a 12ft wide loom there are 8 cards set across the width of the loom. One card is required for each tuft row and there are seven tuft rows per inch. Thus a carpet having a pattern repeat every 96" would require 5376 punched cards. Depending on the complexity, such a pattern would take one punch operative 60 to 120 hours to complete In view of this, it is desirable to have a colour selection system in a carpet loom which avoids the lengthy card preparation process.

Apparatus for selecting the coloured yarns for a gripper carpet loom of the type described comprises a computer memory storage unit to receive a computer programme defining a desired coloured pattern for a carpet, and means to receive signals from the storage unit in accordance with the programme, the signals causing appropriate engagement between the lifting bar and each of the selectors so that the selectors are raised, for loom cycle, an appropriate distance for correct yarn selection.

Such an arrangement completely avoids the use of punched cards and hence their time-consuming and laborious preparation. Rather control software can be generated on floppy discs using a computer aided design unit or alternatively, some other computer memory storage system can be used to generate the electronic signals.

In a first embodiment of the invention preferably each selector blade has a single peg and the lifting bar has seven horizontal lifting stations, positioned vertically above one another, the peg in each selector being pushed out of the selector at the appropriate moment during the upward stroke of the lifting bar so that it engages the particular lifting station required to raise each yarn carrier into the correct position in accordance with the desired carpet pattern Preferably the means for pushing out the peg from each selector in response to the electronic signal from the computer unit, is a solenoid. Alternatively, for example, a pneumatic cylinder may be used.

The solenoid or pneumatic cylinder is preferably connected to the selector peg by a flexible connection, e.g. a spring cable or Bowden wire which is moved by the actuation of the solenoid or the cylinder to push the peg out of the selector. The selector peg may be provided with a notch to engage the appropriate lifting station on being pushed out of the selector. Each lifting station is preferably provided with a latch to engage the notch on the selector peg, as it meets the pushed out peg on its upward stroke.

Preferably, when the lifting bar reaches the top of its stroke, the power to the solenoids or pneumatic cylinders is cut so that when the lifting stations become disengaged from the pegs on the lowering stroke of the lifting bar, the spring loaded cable retracts the pegs within the selectors.

In a second embodiment of the invention preferably each selector blade has seven selector stations cut into the blade, positioned vertically above one another, and the lifting bar is provided with a peg which is pushed out from the lifting bar at the appropriate moment during the upward stroke to engage the particular selection station required to raise the yarn carrier into the correct position.

Preferably each selection station on the selector blade is cut to have a notch which engages a latch provided on the peg. The mechanism by which the peg is pushed out from the lifting bar and then retracted on the downward stroke may comprise a solenoid or pneumatic cylinder and a Bowden Wire as described previously. In a third embodiment of the invention preferably each selector blade is equipped with seven selector pegs positioned vertically above one another and the lifting bar is provided with means to push out the appropriate peg on each selector and with means to engage the pushed out peg during its upward stroke to raise the yarn carrier into the correct position in accordance with the desired carpet pattern.

Preferably the means for pushing out the appropriate peg of the selector, which is provided on the lifting bar, comprises a push pin connected by means of a Bowden Wire to a solenoid or pneumatic cylinder, the pin moving to push out the appropriate selector peg or energisation of the solenoid or activation of the cylinder.

Preferably, there are two rows of staggered push pins mounted on the lifting bar across the width of the loom, each pin in one row operable to push out pegs in the odd numbered selectors and each pin in the other row operable to push out pegs in the even numbered selectors.

A pair of push pins, one from each row. is preferably connected to a single solenoid or pneumatic cylinder each solenoid or cylinder being activated twice during a single lifting stroke of the lifting bar, once for the even numbered selectors, and once for the odd numbered selectors, The power to the solenoid or cylinder may be cut immediately the appropriate peg has been pushed out of the selector to return the pair of push pins to their original positions.

Preferably, after the lifting bar has completed its downward stroke, the pushed out selector pegs are returned to their original position by means of a debbing board.

This third embodiment of the invention is particularly advantageous because one solenoid serves every two selectors thereby halving the number of solenoids required. Furthermore, the solenoids are only activated for the time required to push out the selector pegs and not for the whole lifting stroke of the lifting bar. Thus with the arrangement capital expenditure and power consumption is reduced.

A computer controlled colour selection system for a conventional gripper carpet loom represents a considerable improvement not only in reducing the time taken to prepare the colour selection system for a new weave pattern but also in increasing the complexity of patterns which can be undertaken.

The invention will now be described by way of example with reference to the accompanying drawings in which Figure 1 is a side view of the mechanical and electrical parts of the colour selection apparatus in accordance with the first embodiment of the invention, as they are positioned at the start of the loom cycle; Figure 2 is a side view as in Figure 1 showing the position of the lifting bar and the selector prior to engagement of a lifting station with a pushed-out peg.

Figure 3 is a side view as in Figure 1 showing the position of the selectors when the lifting bar is at the top of the stroke; Figure 4 is a side view as in Figure 1 showing the position of all the components after the power has been cut to the solenoids and the lifting bar is lowered; Figure 5 is a side view of the mechanical and electrical parts of the colour selection apparatus in accordance with the second embodiment of the invention and Figure 6 is a side view of the mechanical and electrical components of the colour selection apparatus in accordance with the third embodiment of the invention.

Referring to Figure 1 the colour selection apparatus in accordance with the first embodiment of the invention comprises a series of selector blades 2 mounted across the width of the loom and each arranged to be vertically slidable between the teeth of two selector guide combs 3 positioned at each end of the vertical selector 2. Each selector 2 is fitted with a peg 4 one end of which is connected by an operating pin 6 to a spring loaded cable (not shown), the cable being surrounded by a flexible connecting tube 8. The other end of each cable is connected to the core spindle of a solenoid 10, the solenoids being mounted on a bracket 12 fitted to the frame 14 of the loom. The flexible connecting tubes 8 are supported at the peg end by holders 16 mounted on the selectors 2 and are supported by the solenoids 10 at the other end.

A lifting bar 18 is mounted by means of precision bearings 20 to a vertical guide rod 22. The lifting bar is provided with seven horizontal lifting stations 24 extending across the entire width of the loom and being arranged vertically above one another.

Each lifting station 24 represents a yarn frame in the yarn carriers (not shown) which are of a hitherto known type and are attached to the selectors 2 by means of the metal wires 26 (see Figure 3) in a known way.

Alternatively, as is also known, the selectors and your carrier could be integrally formed in one piece. The number of lifting stations 24 is one less than the number yarns in the carrier for reasons which will be hereinafter explained.

Referring to Figures 2 and 3 the lifting bar 18 is raised to the top position on the guide rod 22 and then returned to the lowest position with every weaving cycle of the loom. As the lifting bar 18 and hence each lifting station 24 is raised along the guide rod, the stations pass the peg fitted in each selector. At any particular moment during the lifting stroke of the bar 18 the pegs 4 may be pushed out of the selectors 2 (see Figure 2) to engage one of the lifting stations 24. For the purpose of this engagement each peg 4 is provided with a notch 28 which mates exactly with a latch 30 provided on the outer edge of each lifting station 24.

Once the lifting stations 24 and the pegs 14 have engaged, the lifting bar 18 continues up the guide rod 22 to the top position of the stroke, lifting with it the selectors 2 and their associated yarn carriers. The distance each yarn carrier is raised will depend upon which of the seven lifting stations the peg on each selector engages. This, in turn, is controlled by the electronic signals from the computer control unit The pushing out of the selector pegs 4 is brought about by energisation of the solenoids 10 as a result of the electronic signal from the computer unit.

The signal causes the core spindle of the solenoids to be pushed out which in turn pushes the spring loaded cables, against the bias of the spring, through the flexible connecting tube, to act on the operating pin 6 and hence push the peg 14 out of the selector 2 This action takes only a few milliseconds and is timed for each selector by means of the computer programme so that each peg 4 engages the appropriate lifting station to lift the selector and hence the yarn carrier into the correct position for the grippers in accordance with the desired colour pattern for that tuft row of the carpet.

Referring to Figure 4, when the lifting bar 18 reaches the top position of its stroke the power to the solenoids 10 is cut. However, the pegs 4 will remain engaged on the latches 30 of the lifting stations 24 until the lifting bar is lowered to a position where each peg is released from the latch 30. At this point, the spring-loaded cables will immediately retract the pegs 4 into the selectors 2 which are now returned to their base position. The lifting bar 17 continues to be lowered until it reaches its bottom position on the guide rod 22 where it is then ready to begin the next cycle.

It will be apparent that for the top yarn in the carrier to be selected it is not necessary for the yarn carrier to be raised at all so that no corresponding lifting station is necessary on the lifting bar. In the current example the carrier carries eight coloured yarns and hence there are seven lifting stations. However, the colour selection system can be adapted for yarn carriers having twelve or sixteen yarns in which case the lifting bar would have eleven or fifteen lifting stations, respectively.

Referring to Figure 5, in the second embodiment of the invention, the selector blades 32 are mounted at each end in a selector guide comb (not shown) and the lifting bar 38 is mounted by precision bearings 40 on avertical guide rod 42 as described for the previous embodiment.

Each selector 32 has seven selection stations 34 cut into the edge of the blade 32, spaced vertically above one another. The lifting bar 38, which spans the entire width of the loom, is L-shaped in cross-section and mounted on the upper horizontal comb 46 of the lifting bar 38 is a second guide comb 48. Between the teeth of the comb 48, which are spaced in accordance with the pitch of the loom are holes into which are fitted selector pegs 44. Each of the pegs 44 is connected by means of a spring loaded flexible cable or Bowden Wire (not shown) to the core spindle of a solenoid 50, the solenoids being mounted on the frame of the loom as previously described. The cable is surrounded by a flexible connecting tube 52.

During each lifting stroke of the lifting bar 38 each of the solenoids 50 is energised at the appropriate moment to push out the core spindle which, in turn, by means of the Bowden Wire, causes each peg to be pushed out of the guide comb 48 and engage the appropriate selection station 34 of the selector 32. As described with the first embodiment, the timing of the solenoid energisation and hence the distance the selectors and yarn carriers are lifted is determined by signals from the computer unit in accordance with the desired carpet pattern.

The selection stations 34 are shaped to have a notch 54 which engages a latch 56 on the peg 44. Once the peg 44 has engaged the notch 54 the power to the solenoids is cut for the remainder of the lifting stroke of the lifting bar 38, the peg being held in position to rouse the selector 32 by means of the latch 56, On the return stroke of the lifting bar, as the selectors 32 clear the pegs 44, the pegs are retracted to their starting position in the guide comb 48 by means of the spring loaded cable as previously described. As previously mentioned, although the selectors hereinbefore described have seven selection stations eleven or fifteen selection stations could be provided for twelve and sixteen colour looms, respectively.

Figure 6 shows a third embodiment of the invention in which the selector blades 62 are equipped with seven pegs 64,as with a conventional Jacquard colour selector. In this case, however, the lifting bar 68 is provided with means 66 to push out the selector pegs and means 70 to engage the pushed out pegs 64 and raise the selectors 62.

Attached to the top of the lifting bar 68 is a collector plate 72 which extends across the full width of the loom. Two rows of holes, staggered to match the pitch of the loom are drilled across the width of the collector plate 4. Fitted within each of the holes are push pins 74 and 76, the push pins being connected by means of Bowden Wires and flexible connecting tubes 78 and 80 to a solenoid 82. The lower row of push pins 76 are each aligned with the even number selectors and carriers and the upper row 74 with the odd numbered selectors and carriers. Each pair of push pins 74 and 76, one in the upper and one in the lower row are connected to the core spindle of a single solenoid 82.

Thus energisation of each solenoid 82 will result in both of the corresponding push pins 74 and 76 being pushed out of the collector plate 72 towards the selectors where, depending on the point in the lifting stroke of the lifting bar 68 they will engage and push pegs 64 out of the selectors 62.

At the beginning to the loom cycle, before the lifting bar 68 begins its lifting stroke, where the carpet pattern row requires yarn from the bottom station of the carrier on the odd numbered selectors, the appropriate solenoids are energised and the push pins 74 and 76 are pushed out. Only pins in the upper row 74 will push a peg 64 out of the selector since the pins 76 are not correctly aligned at the shape with the even numbered selectors. The solenoids are immediately de-energised to retract the push pins 74 and 76 after the pegs 64 in the odd numbered selectors have been pushed out. The lifting bar 68 then begins the lifting stroke. When the lower row of push pins 76 is aligned with the bottom pegs in the even numbered selectors, the solenoids 82 are energised again where a bottom station yarn is required.The pins 74 are also pushed out but have no effect on the odd-numbered selector pegs 64 since they are not now in alignment. The solenoids 82 are immediately de-energised following the pushing out of the selector pegs. As the lifting bar 68 continues its stroke, so the energisation and de-energisation of the appropriate solenoids occurs for each of the remaining six pegs in the selector, in accordance with the desired carpet pattern determined by the computer programme Each solenoid will usually be energised twice during a single loom cycle except where the top yarn station is required and the yarn carrier does not need lifting. The lifting bar 68 is provided with a bar 70 which actually engages the pushed out selector pegs and lifts the selectors during the lifting stoke.

On the return stroke of the lifting bar 68, the push pins 74 and 76 are all retracted since the solenoids are de-energised so that the lifting bar 68 and the selectors 62 may freely move back to their starting position. The selector pegs 64 are pushed back into the selector blades 62 by means of a dabbing board (not shown) as with a conventional Jacquard.

An advantage of the particular embodiment is that only one solenoid is required for every two selectors and carriers, thus reducing the capital expenditure and the power input.

The computer operated colour selection systems described herein represent a considerable advantage over the conventional mechanical Jacquard. The computer may be programmed to weave any carpet pattern and any length of pattern repeat. Further, the charge time at the loom is reduced considerably when a new pattern is introduced and several patterns can be produced from a single creel of colours.

Claims (15)

CLAIMS:

1. Apparatus for selecting the coloured yarn for a gripper carpet loom of the type described comprising a computer memory storage unit to receive a computer program defining a desired colour pattern for a carpet and means to receive signals from the storage unit in accordance with the program, the signals causing appropriate engagement between the lifting bar and each of the selectors so that the selectors are raised, for a loom cycle, an appropriate distance for correct yarn selection.

2. Apparatus as claimed in Claim 1 wherein each selector blade has a single peg and a lifting bar has a plurality of horizontal lifting stations positioned vertically above each other, the peg in each selector being pushed out of the selector at the appopriate moment in response to a signal from the computer unit during the upward stroke of the lifting bar so that it engages the particular lifting station required to raise each yarn carrier into the correct position in accordance with the desired coloured pattern.

3. Apparatus as claimed in Claim 2 wherein the lifting bar has seven horizontal stations.

4. Apparatus as claimed in either Claim 2 or 3 wherein means are provided for engaging the peg with the appropriate lifting station during the upward stroke of the lifting bar comprising a notch provided on the selector peg and a latch provided on each station, the latch on the appropriate station engaging the notch on the selector peg on its upward stroke.

5. Apparatus as claimed in Claim 1 wherein each selector blade has a plurality of stations cut thereinto, positioned vertically above one another, and the lifting bar is provided with a peg which is pushed out therefrom at the appropriate moment during the upward stroke thereof to engage the particular station required to raise the yarn carrier into the correct position.

6. Apparatus as claimed in Claim 5 wherein each selector blade has seven stations.

7. Apparatus as claimed in Claim 5 or Claim 6 wherein each station on the selector blade is in the form of a notch arranged to engage a latch provided on the peg during the upward stroke of the lifting bar.

8. Apparatus as claimed in any one of Claims 2 to 7 wherein the means for pushing out the peg in response to an electronic signal from the computer unit is a solenoid.

9. Apparatus as claimed in any one of Claims 2 to 7 wherein the means for pushing out the peg in response to an electronic signal from the computer is a pneumatic cylinder.

10. Apparatus as claimed in any one of Claims 2 to 9 wherein means for pushing out the peg in response to an electronic signal from the computer unit is connected to the peg by a flexible connection which is moved by actuation of the pushing means to push the peg of the selector.

11. Apparatus as claimed in any one of Claims 2 to 10 wherein when the lifting bar reaches the top of its stroke, the means for pushing out the peg are disengaged, the means for engaging the station and the peg being released as the lifting bar moves through its lowering stroke and wherein means are provided for retracting the pegs.

12. Apparatus as claimed in Claim 11 when dependant on claim 10 wherein the retraction means comprise the flexible connection between the pushing means and the selector peg.

13. An apparatus as claimed in Claim 1 wherein each selector blade is provided with a plurality of selector pegs positioned vertically above one another, the lifting bar being provided with means to push out the appropriate peg on each selector and means to engage the pushed out peg during its upward stroke to raise the yarn carrier into the correct position in accordance with the desired carpet pattern.

14. Apparatus as claimed in Claim 13 wherein the means for pushing out the appropriate peg comprises a push pin connected by a flexible connector to a means for moving the pin to cause the appropriate selector peg to be pushed out.

15. Apparatus as claimed in Claim 14 wherein two