Method for weaving pile fabrics with variable pile height

Abstract

The present invention relates to a method for weaving pile fabrics having at least two different pile heights in a same pile row in a weaving machine of the gripper-Axminster type, comprising at least two pile yarn carriers (2, 3) separately driven for the selection according to a pattern to be woven, of one or several pile yarns (4) being presented, in a position (5) selected, to a gripper (1) driven by an oscillating gripper shaft, provided to draw the selected pile yarn (4) off the pile yarn carrier (2, 3) throughout a length desired, by rotating the gripper shaft. The said weaving machine furthermore comprises a cutting device (6) to cut through the pile yarn (4) selected after the selection and after which this pile yarn (4) is inserted into the fabric. The present invention likewise relates to pile fabrics manufactured according to such a method and to a gripper-Axminster weaving machine to apply this method.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 up to and including FIG. 5 is representing a number of positions of two pile yarn carriers with selected pile yarns, grippers and a cutting system in order to clarify the method according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It may be obvious that, in practice, it may be possible that there are more pile yarn carriers and grippers and that normally a pile yarn carrier is containing more than one pile yarn which may be selected in accordance with a pattern to be woven. For the sake of clarity of the drawings, only a restricted number of pile yarns, pile yarn carriers and grippers are represented here.

The present invention relates to a method for weaving pile fabrics having at least two different pile heights in a same pile row on a weaving machine of the gripper-Axminster type. The said weaving machine is provided with a row of grippers (1) which are installed on an oscillating gripper shaft. Furthermore, the weaving machine is provided with at least two individual motor driven pile yarn carriers (2, 3) for the selection (in accordance with a pattern to be woven) of one or several pile yarns (4) which in a selected position (5) are being presented to a gripper (1). By rotating the gripper shaft, the grippers (1) will draw the pile yarn selected (4), throughout the length desired, off the pile yarn carrier (2, 3). In order to cut through the pile yarn selected (4) to the length desired, the weaving machine is additionally provided with a cutting device (6).

The method according to the present invention is characterized in that it comprises the following stages:

• • bringing one or several pile yarn carriers (3) out of reach of the cutting device (6) by controlling the separate drives;
  • cutting through, by a first cutting motion of the cutting device (6), the pile yarns (4) selected which are situated in the pile yarn carriers (2) which are positioned within reach of the cutting device (6) in order to obtain pile yarns having a first pile height;
  • returning at least a first part of the pile yarn carriers (3) to their position in which they are presenting the pile yarns selected in the position (5) selected, by controlling their separate motors;
  • performing an additional rotation of the gripper shaft, the pile yarns selected, situated in the said first part of the pile yarn carriers (3), being drawn further off these pile yarn carrier;
  • cutting through, with a second cutting motion of the cutting device (6), the pile yarns having been drawn off further, in order to obtain pile yarns having a second pile height.

After this, the gripper shaft is moving on further towards the fabric, in order to position the grippers (1) below the fell of the fabric, after which a weft is inserted into the fabric and the gripper shaft is moving back the grippers (1) and will open them at a height desired in order to release the tuft to be presented again to the Jacquard machine in order to take the next pile yarn (4), selected by the Jacquard machine, from the pile yarn carriers (2, 3).

In accordance with the method according to the present invention, it will become possible to realize a third pile height within the same pile row. Namely, after having cut through the pile yarns drawn off further, in order to obtain pile yarns having a second pile height, having at least a second part of the pile yarn carriers (3) move back again to their position in which they present the pile yarn selected in the position selected. And then, by drawing off additionally the pile yarns selected, situated in the said second part by a further rotation of the gripper shaft and subsequently cutting them through by means of a third cutting motion of the cutting device, pile yarns having a third pile height are obtained.

The cutting device (6) will remain in a presentation position, between the two cutting motions (or several, if a third pile height will be realized). This will restrict the motion necessary to be performed in order to proceed to the cutting operation and to return. This means a saving of time, which is important to be able to perform several cutting cycles during one weaving cycle.

It is possible to multiply the number of cutting bits on the cutting device (6) to obtain a multiple which will be equal to the number of different pile heights, so that the cutting device (6), at each cutting motion during the cycle will be moving further on in the same direction, which will produce a further saving of time and may enable more cutting cycles to be performed during one weaving cycle. A cutting bit is an exchangeable cutting element which is installed on the cutting device. Normally, several cutting bits are regularly distributed across the width of the weaving machine. The distance between two cutting bits will determine the distance the cutting device has to move in order to cut through all the pile yarns.

The number of cutting bits may remain the same, the cutting device (6) moving in one direction for cutting through the pile yarns (4) with the first pile height, whereas for cutting through the pile yarns (4) with the second pile height, the cutting device (6) will be moving in the opposite direction.

The principle of the method according to the invention is represented in the FIGS. 1 up to and including 5, the FIGS. 1a and 1b being a representation of two pile yarn carriers (2, 3) each having selected a pile yarn (4) (in accordance with the pattern to be woven) and which are presenting the pile yarn (4) selected to a gripper (1) in a pre-defined position (5).

After the grippers having gripped the pile yarn (4) selected a pile yarn carrier (3) selected will be brought out of reach of the cutting device (6) and the pile warp yarn (4), provided in the non-selected pile yarn carrier (2) (i.e. the pile yarn carrier remaining in its position) will be drawn off the non-selected pile yarn carrier, throughout a first tuft length, by rotating the gripper shaft. (see FIGS. 2a and 2b)

Subsequently, as represented in FIG. 3, the pile yarn (4) which is situated in the non-selected pile yarn carrier (2) will be cut through by means of a first cutting motion of the cutting device (6). After this pile yarn (4) has been cut through, the cutting device (6) will return into its presentation position, ready to perform a next cutting motion.

After the pile yarn (4) of the non-selected pile yarn carrier (2) has been cut through, the pile yarn carrier (3) selected will return back into its original position (see FIG. 4), in which the pile yarn selected (4) will be brought into the position (5) selected. Because of an additional rotation of the gripper shaft the pile yarn (4) selected in the pile yarn carrier (3) selected will be drawn off by the gripper (1) throughout a second tuft length. The cutting device (6) will cut through this pile yarn (4) drawn off throughout a second tuft length.

Finally, the cutting device (6), as represented in FIG. 5, will withdraw entirely and the grippers (1) will (because of the further oscillation of the gripper shaft) bring the pile yarns below the fabric fell, after which a weft will be inserted and the grippers (1) will be brought back towards the pile yarn carriers (2, 3) and in the moment, corresponding with the pile length desired of the pile in the fabric, the pile yarn will be released.

Claims

1. Method for weaving pile fabrics having at least two different pile heights in a same pile row on a weaving machine of the gripper-Axminster type, comprising at least two pile yarn carriers (2, 3) separately controlled for the selection, according to a pattern to be woven, of one or several pile yarns (4) being presented, in a position selected, to a gripper (1) driven by an oscillating gripper shaft, provided to draw the selected pile yarn (4) off the pile yarn carrier (2, 3), throughout a length desired, by rotating the gripper shaft, the said weaving machine furthermore comprising a cutting device (6) to cut through the pile yarns (4) selected after the selection, and this pile yarn (4) being inserted into the fabric, after the pile warp yarn (4) having been cut through, characterized in that the method is comprising the following stages: bringing the one or several pile yarn carriers (3) out of reach of the cutting device (6) by means of their separate drives;cutting through, by means of a first cutting motion of the cutting device (6), the pile yarns (4) selected which are in the pile yarn carriers (2), which are positioned in the reach of the cutting device (6) in order to obtain pile yarns having a first pile height;returning, by means of their separate drives, at least a first part of the pile yarn carriers (3) into their positions in which they will present the pile yarn selected in the position (5) selected;performing an additional rotation of the gripper shaft, drawing the pile yarns selected, which are situated in the in the said first part of the pile yarn carriers (3), further off these pile yarn carriers;cutting through, by means of a second cutting motion of the cutting device (6), the pile yarns having been drawn off further, in order to obtain pile yarns with a second pile height.

2. Method according to claim 1, characterized in that, after the pile yarns drawn off further, in order to obtain pile yarns having a second pile height, at least a second part of the pile yarn carriers, by means of their separate drives, are returning to their positions in which they will present the pile yarn selected, in the position selected (5), after which the pile yarns selected, which are presented, in the said second position, by the second part of the pile yarn carriers, will be drawn off these pile yarn carriers additionally by means of a further rotation of the gripper shaft and next these pile yarns will be cut through by means of a third cutting motion of the cutting device (6) in order to obtain pile yarns having a third pile height.

3. Method according to claim 1, characterized in that the cutting device (6), after having performed a cutting motion, will return to the presentation position.

4. Method according to claim 1, characterized in that the cutting device (6) will be driven by a servomotor in order to cut through the pile yarns in a manner synchronic with the other motions of the weaving machine.

5. Method according to claim 1, characterized in that the gripper shaft (1) is driven by a servomotor in order to, in a manner synchronized with the other motions of the weaving machine, position the grippers (1) for the pile yarn carriers (2, 3), to grip the pile yarns (4) selected and to draw off the pile yarn carriers (2, 3) according to the length desired and to insert the pile yarns cut off into the fabric.

6. Method according to claim 1, characterized in that, when returning at least a first part of the pile yarn carriers (3), these pile yarn carriers will be moving in a manner synchronized with the gripper shaft.

7. Method according to claim 3, characterized in that, when bringing back at least a first part of the pile yarn carriers (3), these pile yarn carriers will be moving in a manner synchronized with the cutting device (6) returning to its presentation position.

8. Pile fabric having at least two different pile heights in a same row, characterized in that the said pile fabric will be manufactured according to claim 1.

9. Gripper-Axminster weaving machine, characterized in that the gripper-Axminster weaving machine is equipped to apply a method according to claim 1.