Textiles: weaving – Pile tufting – Portable supply
Reexamination Certificate
2003-06-26
2004-11-23
Worrell, Danny (Department: 3765)
Textiles: weaving
Pile tufting
Portable supply
C139S00700A
Reexamination Certificate
active
06820656
ABSTRACT:
BACKGROUND TO THE INVENTION
In making carpet, particularly patterned Axminster carpet, a yarn tuft forming unit is used to provide yarn of a particular colour to each weaving point of the carpet. In conventional Axminster weaving there are two principal ways which the yarn tuft formation is carried out. The first way is on a Jacquard Axminster loom, and the second is on a spool Axminster loom.
On a gripper Jacquard Axminster loom each weaving point includes a yarn carrier which is normally fed by eight yarns usually of different colour and the Jacquard mechanism moves the carrier to bring a selected yarn to the yarn selection position. A gripper moves towards the carrier, grips the yarn at the yarn selection position then relative movement apart of the gripper and the carrier pulls a predetermined length of yarn from the carrier. The yarn is then cut to form a tuft and moved by the gripper to the weaving point. The tuft carried by the gripper is of the appropriate colour for the tuft to be supplied to the next row of carpet to be woven. For a conventional 12 foot (4 m) loom there are over a 1000 weaving points across the loom and thus the creel supplying yarn to the loom has to have the potential of carrying over 8000 yarn packages. Typically, when the creel includes measured quantities of yarn in each tarn package an allowance of an additional eighteen metres of yarn is provided in each yarn package. Accordingly, the greater the number of yarn packages the greater the wastage. In spite of such a large creel size a designer of such carpets is relatively limited since the number of colours available for each column of tufts extending in the warp direction of the finished carpet and corresponding to a single weaving point is limited to only eight throughout each pattern repeat. Jacquards are also known in which the yarn carrier can hold sixteen different yarns. These require an even larger creel.
Spool Axminster looms provide a designer with greater flexibility. In spool Axminster looms a separate spool is provided for each row of the pattern repeat and each spool has a separate yarn winding for each weaving point along each row. Therefore, at least theoretically, the designer has an infinite number of colour choices for each column and row of each pattern repeat. However, in practice, as the number of colour choices used for each column and row of the design increases, the number of yarn packages needed for the spool winding operation also increases. Further, the spool winder must be set up differently for the winding of each spool which is time consuming. When a large number of different colours are used in both the column and row or warp and weft direction of each pattern repeat the number of different coloured yarn packages supplying the spool winder can be even larger than those on a creel of a typical Jacquard Axminster loom. The pattern repeat on spool looms is limited by the number of spools available in the spool chain. Further, there is considerably greater yarn wastage from a spool Axminster loom than a gripper Axminster loom because, on completion of a run, waste is generated from each weaving point of each row of the pattern repeat.
DISCUSSION OF PRIOR ART
In both the Jacquard and spool Axminster looms a row of tufts for a complete row of the carpet is created simultaneously and transferred to the weaving point at which they are woven into a backing to produce the carpet. An entirely different approach to yarn selection for carpet production has recently been proposed in WO 95/31594. In this, it is proposed that tufts of yarn to form a row of the carpet are produced by first loading yarn tufts into a tuft carrier and then transferring the yarn tufts from the tuft carrier to the weaving points. To achieve this a large number of different tuft forming units, typically one per weaving point, are provided along the length of a path with typically each tuft forming unit being supplied with yarn of only a single colour. As the tuft carrier is moved along the path it receives tufts of appropriate colour in each of its tuft holding sites. The tuft carrier is subsequently moved so that all the tufts for each row can be gripped by grippers and transferred to the weaving point simultaneously. Thus, the tufts are not usually all formed simultaneously and hence the tuft formation is, at least to some extent, decoupled from the weaving operation. Therefore, tuft formation can take place at the same time as the weaving operation and thus tuft formation can take place substantially continuously throughout the operation of the loom. This is to be contrasted with the conventional spool or gripper type looms where tuft formation takes place over only about half of each weaving cycle.
In examples given in WO 95/31594 it is suggested that partly as a result of forming the tufts throughout the entire weaving cycle it is possible to, for example, increase the speed of the tuft forming operation by four times. It is also explained that if this were possible and it was intended to operate the loom at the same speed as a conventional loom then it would be possible to reduce the size of its creel by a quarter since, in effect, each tuft forming unit would supply tufts for four weaving points. However, nowhere in this document does it exemplify an arrangement in which there are less yarn packages than the number of weaving points.
Whilst the above document specifically exemplifies only the supply of yarn of a single colour to each tuft forming unit it does disclose the theoretical possibility of providing yarn of a number of different colours to each tuft forming unit and somehow, in an unspecified way, selecting yarn of an appropriate colour for each weaving point. If this teaching is followed the creel size would not be reduced significantly. The above document also discusses the theoretical possibility of holding the yarn carrier stationary whilst moving the tuft forming unit. However, neither of these theoretical possibilities are exemplified nor is it explained how they could be achieved nor what advantages would accrue.
In WO 01/88240, a carpet weaving loom is described which includes one or more tuft forming units, the or each of which supplies tufts to a large number of weaving points, typically a number of tens of weaving points, sequentially. A loom, particularly one for producing samples may have only a single tuft forming unit and this may supply tufts for three hundred or more weaving points. Typically, for carpet production the loom includes a plurality of tuft forming units and each supplies tufts for between twenty and one hundred and twenty weaving points. With such an arrangement a great reduction in the number of yarn packages in the creel is obtainable since the potential number of yarn packages is that needed conventionally divided by the number of weaving points supplied by the or each tuft forming unit so reducing it to below one hundred in some instances, whilst also giving the designer a greater number of colour choices in each column of tufts extending in the warp direction.
SUMMARY OF THE INVENTION
According to a first aspect of this invention a yarn tuft forming unit comprises a yarn selector wheel with provision for holding a number of different yarns arranged around it, means to drive the selector wheel into a selected one of a number of angularly discrete positions to bring a selected yarn to a loading position, a puller for engaging the selected yarn at the loading position and pulling a predetermined length of the selected yarn from the selector wheel, and a cutting mechanism to cut the selected yarn to form a tuft of predetermined length.
The yarns may be arranged around the periphery of the selector wheel and extend in a direction generally parallel to its axis of rotation, but, preferably the yarns extend generally radially to the periphery of the wheel. Typically, such a yarn selector wheel has provision for containing more than 10 different yarns and typically 12,16,24 or 32 different yarns. Preferably the selector wheel is driven into and between its pre
Brintons Limited
Sughrue & Mion, PLLC
Worrell Danny
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