EP1888826A2

EP1888826A2 - Terry loom

Info

Publication number: EP1888826A2
Application number: EP06754175A
Authority: EP
Inventors: Jürgen WARMER; Filip Deconinck; Veerle Vanwassenhove
Original assignee: Picanol NV
Current assignee: Picanol NV
Priority date: 2005-06-10
Filing date: 2006-06-07
Publication date: 2008-02-20
Anticipated expiration: 2026-06-07
Also published as: CN101194057A; WO2006131325A3; DE102005028127A1; EP1888826B1; ATE493528T1; WO2006131325A2; CN101194057B; DE602006019237D1

Abstract

In the case of a terry loom, provision is made for the cloth (20) to be displaceable relative to a device for beating up weft yarns through to-and-fro motion of backrest and breast beam, wherein only the backrest for the ground warp and the breast beam may be moved to and fro by means of a drive, while the backrest (16) for the pile warp (13) is held so as to be resiliently compliant substantially in the weaving direction.

Description

Terry loom

The invention relates to a terry loom with devices for supplying a ground warp and a pile warp, which each comprise a backrest, with a shedding device, with a device for inserting weft yarns, with a device for beating up the weft yarns and with a device for drawing off cloth, which comprises a breast beam.

Terry looms of the above-mentioned type have long been known, for example from US 607 377 or from US 15 95 289. Displacement of the cloth relative to the device for beating up a weft yarn causes variation of the distance between the always constant beat-up line and the fell. If, after a plurality of picks and beat-ups effected at a distance from the fell, the cloth is displaced in such a way that the fell is moved closer to the reed, the pre- viously inserted weft yarns are carried along towards the fell. In the process, they move relative to the more tightly tensioned warp yams of the ground warp, while carrying with them the only loosely tensioned warp yams of the pile warp. In the process, the warp yarns of the pile warp form loops. In order to displace the cloth relative to the beating- up device, the backrests for the ground warp and pile warp are moved to and fro by means of a drive means jointly with and in the same direction as the breast beam.

The object of the invention is to simplify a loom of the above-mentioned type.

This object is achieved in that the backrest for the pile warp is resiliently held substan- tially in the weaving direction. The resilient mounting of the pile warp backrest ensures that, on movement of the warp yarns for shed levelling or on movement of the cloth, no pile yarns are pulled back out of the cloth, so undoing loop formation. Due to the resilient mounting of the pile warp backrest, the latter may move together with the cloth if the cloth is again moved in such a way, after a plurality of weft yarns have been beaten up to the fell, that the fell moves away from the beat-up line of the beating-up device.

Provision is made, in an embodiment of the invention, for a deflecting element to be arranged upstream of the backrest for the pile warp. In this way, greater wrap of the back- rest may be obtained. It is advantageous for the backrest and the deflecting element to be arranged in such a way that the pile warp yarns run to and from the backrest approximately parallel to the weaving direction and close to the weaving plane. In this way it is ensured that even a relatively small movement of the backrest in the direction of the device for beating up the weft yarns relieves the load on the pile warp yarns to a relatively high degree.

A further embodiment of the invention provides for the warp yarns of the pile warp to have their own warp stop motion means assigned to them downstream of their backrest. This simplifies operation and in particular also makes it easier to detect any warp break- age that may have occurred.

A further embodiment of the invention provides for the backrest to take the form of a bar, which is mounted on spring elements by means of brackets pointing with their narrow side in the weaving direction. These brackets hinder pile warp yarn running only slightly. The brackets allow the spring elements to be arranged under the warp yarns, so as to make them readily accessible to an operator.

A further embodiment of the invention provides for the spring elements to take the form of a plurality of leaf spring assemblies, which are distributed over the cloth width and oriented substantially perpendicularly to the weaving direction. Such leaf spring assemblies allow uniform adjustment of the necessary spring forces, wherein an at least ap- proximately linear spring characteristic is provided. The preferably pretensioned spring elements are deflected in accordance with changes in tension. The spring forces may be adjusted by means of the number of leaf springs in the leaf spring assemblies.

Further features and advantages of the invention are revealed by the following description of the embodiment illustrated in the drawings.

Fig. 1 shows a schematic representation of a terry loom according to the invention,

Fig. 2 is a perspective view of a mounting arrangement for the pile warp yarn backrest,

Fig. 3 shows a detail of Fig. 2 on an enlarged scale and viewed in the direction of arrow in in Fig. 2,

Fig. 4 is a side view of the pile warp backrest and its mounting arrangement,

Fig. 5 is a perspective view, on a somewhat smaller scale, of the pile warp backrest with a device for measuring warp tension and

Fig. 6 is a modification of Fig. 4.

The terry loom illustrated schematically in Fig. 1 has a warp beam 10 with a ground warp 11 and a warp beam 12 with a pile warp 13. The ground warp 11 is deflected over a backrest 14 into the weaving plane. The pile warp 13 runs over a deflector 15 to its own backrest 16 and thence likewise into the weaving plane. As is clear from Fig. 1, the deflector 15 is arranged in such a way that the pile warp 13 is wrapped round the backrest 16 over an angle of approximately 150°, wherein the pile warp 13 runs approximately parallel to the weaving plane from the deflector 15 to the backrest 16 and from the backrest 16 to the device 17 means. Upstream of the backrest 14 of the ground warp 11 there is arranged a stationary deflection roll 44, which is rotatable about a shaft 40. In this way, the warp yarns HA run from a full warp beam 10 and the warp yarns HB from an almost empty warp beam 10 substantially in the same way to the backrest 14. For the same reason, a stationary deflection roll 45 is arranged upstream of the deflector 15, such that the warp yarns 13A of the pile warp 13 and the warp yarns 13B, which come from a full or almost empty warp beam 12, run in substantially the same way to the deflector 15.

Weft yams are inserted into the successively formed sheds. The device provided for inserting weft yarns is for example a device as is conventionally used for air-jet looms. This has two main blowing nozzles arranged one behind the other and next to the shed and a row of relay nozzles, which are arranged on a sley 18 and whose blowing direction is directed towards a weft insertion channel of a reed 19. The reed 19, which is fitted on the sley 18 and swivels therewith, brings the inserted weft yarns up to a beat-up line. At this beat-up line, the inserted weft yarns are tied up by means of the warp yarns when the shed is changed, i.e. a number of warp yarns change from the upper position into the lower position and a number of warp yarns change from the lower position into the upper position.

The cloth 20 formed in this way is drawn off by means of a draw-off roller 21, for example a sand roller or needle beam, and wound onto a cloth beam 22. A breast beam 23 and two deflectors 24, 25 are arranged upstream of the draw-off roller 21 in the draw -off direction.

In this embodiment, the backrest 14 for the ground warp 11 may be swivelled about a shaft 40 parallel thereto by means of levers 26 holding its two ends. The breast beam 23 is held by means of two levers 27 acting on its end, said levers being swivellable about the axis of the deflector 24. The levers 26, 27 are acted upon by transmission bars 28, 29, whose respective other ends are coupled to a swivel arm 30. On either side of the cloth width, such swivel arms 30 are arranged non-rotatably on a shaft which may be swivelled to and fro by means of a geared motor 31, preferably a stepping motor. By means of this drive system consisting of the levers 26, 27, the transmission bars 28, 29, the swivel arms 30 and the drive motor 31, the backrest 14 for the ground warp 11 and the breast beam 23 may be moved to and fro in the same direction. During this to-and-fro motion, the cloth 20 is displaced relative to the reed 19, which may be swivelled between a rear position and a front position. In the process, the distance from the fell of the cloth 20 to the beat-up line of the reed 19 is varied. The lever 26, which is rotatable about the shaft 40 and bears the backrest 14, comprises an arm 46, which is held by a spring ele- ment 47 which is supported on the frame of the loom.

The backrest 16, the design of which will be explained in greater detail with reference to Figs. 2 and 3, is not provided with a drive. However, it is held resiliently substantially in the weaving direction, such that it can follow satisfactorily the movement of the cloth 20. If, for example, provision is made for the cloth 20 to be moved away from the reed 19, to the left in Fig. 1, after beat-up of a weft yarn to the fell, the next weft yarns are not beaten up to the fell, but rather remain at a distance therefrom. If, for example, the cloth 20 with its fell is then moved back closer to the reed 19 after two to four or more picks, by moving backrest 14 and breast beam 23 accordingly (to the right in Fig. 1), the reed 19 moves the last inserted weft yarns up to the fell on the next beat-up. In the process, these weft yarns slide along the warp yarns of the ground warp 11, which is relatively tightly tensioned. The warp yarns of the pile warp 13 are less tightly tensioned, such that the weft yarns carry these warp yarns of the pile warp 13 with them during the beat-up movement. In this way, the warp yarns of the pile warp 13 are formed into loops. If the backrest 14 and breast beam 23 are then swivelled again by means of the drive motor 31in such a way that the fell of the cloth 20 moves away from the reed 19, the warp yarns of the pile warp 13 are tightened. They then draw the backrest 16 in the direction of the reed 19, wherein the resilient mounting of the backrest 16 yields in such a way that the previously formed loops are not pulled back out of the cloth 20 as the cloth 20 is dis- placed. The deflector 15 assists in this resilient function, said deflector being to this end of elastic, for example rubber-elastic, construction. The deflector 15 preferably takes the form of a so-called oscillating sheet shaft, i.e. a cylindrically curved spring steel sheet whose overlapping edges are attached to a bar. In a modified embodiment, the deflector 15 is mounted rotatably and/or provided with a rotary drive. This type of deflector 15 is advantageous as an addition to the backrest 16, allowing shed levelling and more reliably ensuring a terry weave. The resilient mounting arrangement of the backrest 16 for the pile warp 13 is illustrated in detail in Figs. 2 and 3. The backrest 16 is a tubular bar, which is held by means of narrow brackets 32 each comprising a semicircular recess. The brackets 32 are attached with T-shaped holders 33 to the upper ends of leaf spring assemblies 34 by means of screws 41. The lower ends of the leaf spring assemblies are fixed by means of screws 42 to a holding block 35, which is in turn attached by means of screws 43 to a holding rail 36. The holding rail 36 is fixed to a crossbar 37, which takes the form of a square tube. The holding rail 36 is provided with an undercut groove 38, in which nuts are guided, into which screws 43 are screwed, which hold the holding blocks 35 in displaceable manner. The holding rail 36 is attached to the crossbar 37 by means of screws 48. The holders 33 and the brackets 32 are connected together by means of screws 49.

As is clear from Fig. 2, there is provided a plurality of leaf spring assemblies 34 distrib- uted evenly over the cloth width, these holding the backrest 16 in such a way that it yields in the warp direction, wherein the leaf spring assemblies 34 bend accordingly.

As is further illustrated in Fig. 2, a warp stop motion 39 is arranged downstream of the backrest 16 of the pile warp 13, such that the warp yarns of the pile warp 13 are moni- tored for warp breakage separately from the warp yarns of the ground warp 11. The warp yarns of the ground warp 11 have their own warp stop motion assigned to them.

The leaf spring assemblies 34 extend substantially vertically, i.e. substantially perpendicularly to the weaving plane or warp direction, such that the backrest 16 is held so as to be resilient parallel to the weaving plane or warp direction. The leaf spring assemblies 34 are arranged under the pile warp 13 and ground warp 11, the brackets 32 projecting therethrough.

As is clear in particular from Fig. 4, the brackets 32 are provided with borders 50. A somewhat more than semicylindrical receptacle 60 serves in mounting the backrest 16, which may be clipped into this receptacle 60. The receptacle 60 is made of a vibration- reducing, wear-resistant material. In this way, it is ensured on the one hand that the brackets 32 are protected against wear and on the other hand that vibrations of the backrest 16 are not fully transmitted to the brackets 32, so suppressing noise. The brackets 32 themselves are arranged with their flat sides parallel to the warp yarns of the ground warp 11 and the pile warp 13, such that they hinder warp yarn running only slightly. The edges of the narrow sides are protected by the border 50.

Fig. 5 shows an embodiment in which the crossbar may be rotated together with the spring assemblies 34, the brackets 32 and the backrest 16 about an axis extending paral- IeI to the axis of the backrest 16. To this end, the crossbar 37 is provided at both ends with journals 51, which are mounted in the machine frame by means of bearings 52. The crossbar 37 is provided with a holder 55, to which a bar 56 is attached by means of a screw 58. The bar 56 is attached to a holder 54 by means of a screw. The holder 54 comprises a force transducer, with which the forces exerted by the warp yarns of the pile warp 13 on the backrest 16 may be detected. In the exemplary embodiment illustrated, the force transducer 53 is adjustable by means of a drive 59, for example a linear motor, such that the crossbar 37 may be swivelled and thus the force may be adjusted with which the warp yarns of the pile warp are tensioned. Pretensioning of the leaf spring assemblies 34 is also adjusted thereby.

The number of brackets 32 and thus of spring assemblies may be selected as a function of the width, as may their spacing over the width. The spring stiffness of the leaf spring assemblies 34 is set to a lower value, for example half the value, at the two ends of the backrest. This may be achieved simply by reducing the number of leaf springs in the leaf spring assemblies 34 accordingly. In the event of a change in cloth width, the number of brackets 32 and/or the number of leaf springs in the leaf spring assemblies 34 may be suitably adjusted.

In a further development of the invention, a lubricant is appropriately provided between the leaf springs of the leaf spring assemblies 34. In the embodiment of Fig. 6 the crossbar 37 is provided with a stopper element 61. The stopper element 61 of this embodiment is a leaf spring plate which faces by a bent end the leaf spring assembly 34. The plate is mounted on the crossbar 37 by means of bolts 62 and seal rings 63. The bolts 62 which are arranged in a row extending in longitudinal direction of the crossbar 37 extend through slits 64 of the plate. The slits 64 are directed perpendicular to the longitudinal direction of the crossbar 37 and the plate so that the plate is adjustable in the direction of the arrow 65 with respect to the leaf spring assembly 34.

When the leaf spring assembly 34 comes into contact with the stopper element 61 the movement of the leaf spring assembly 34 is limited. Also the spring characteristic or the stiffness of the leaf spring is increased. Such a stopper element 61 is of advantage if the tension in the warp yarns 13 is substantially increased.

The backrest 16 according to the invention of the pile warp 13, which is held so as to be resilient substantially in the weaving direction, may be used in any type of terry loom. For example, said backrest may also be used in a terry loom in which the terry cloth is produced by means of sley adjustment. Such a terry loom with sley adjustment is described in detail for example in EP 1 201 807 Al. It comprises a stationarily arranged breast beam.

It goes without saying that the invention is not restricted to a terry loom in which the weft yarns are inserted by means of air jets. It may also readily be applied to rapier looms, projectile looms, shuttle looms, gripper shuttle looms, water jet looms or any other type of loom. The backrest according to the invention, which is resilient in the weaving direction, may also be retrofitted to any type of loom, such that said loom may be accordingly upgraded. The backrest arrangement of the present invention is especially useful for pile warp yarns of a loom because it is suitable for loosely or less tightly ten- sioned warp yarns of a loom. The invention is not restricted to the exemplary embodiment illustrated. Other drives may also be readily provided for moving backrest 14 and breast beam 23 to and fro. In particular, cam drives may be provided, which derive their movement from a main shaft of the loom.

Claims

1. A terry loom with devices for supplying a ground warp (11) and a pile warp (13), which each comprise a backrest (14, 16), with a shedding device (17), with a de- vice for inserting weft yarns, with a device (18, 19) for beating up the weft yarns and with a device (21, 23, 24, 25) for drawing off cloth (20), which comprises a breast beam (23), characterised in that the backrest (16) for the pile warp (13) is resiliently held substantially in the weaving direction.

2. A terry loom according to claim 1, characterised in that a deflecting element (15) is arranged upstream of the backrest (16).

3. A terry loom according to claim 1 or 2, characterised in that the backrest (16) for the pile warp (13) and the deflecting element (15) are arranged in such a way that the pile warp yarns run to and from the backrest (16) approximately parallel to the weaving direction.

4. A terry loom according to any one of claims 1 to 3, characterised in that the pile warp yarns have their own warp stop motion (39) assigned to them downstream of their backrest (16).

5. A terry loom according to any one of claims 1 to 4, characterised in that the backrest (16) takes the form of a bar, which is mounted on spring elements (34) by means of brackets (32) pointing with their narrow side in the weaving direction.

6. A terry loom according to claim 5, characterised in that the spring elements take the form of a plurality of leaf spring assemblies (34), which are distributed over the cloth width and oriented substantially perpendicularly to the warp direction.

7. A terry loom according to claim 5, characterised in that the backrest (16) for the pile warp (13) is mounted rotatably in the brackets (32).

8. A terry loom according to any one of claims 1 to 7, characterised in that the backrest (14) for the ground warp (11) and the breast beam (23) may be moved to and fro in the warp direction by means of drives (26, 27, 28).

9. A terry loom according to any one of claims 1 to 8, characterised in that the spring elements (34) of the brackets (32) holding the backrest are arranged under the warp yarns of the pile warp (13) and the ground warp (11).

10. A terry loom according to any one of claims 1 to 9, characterised in that the backrest (16) for the pile warp (13) is held by means of a holding device (51 to 59), which comprises devices for detecting the tension of the warp yarns of the pile warp (13).

11. A terry loom according to claim 10, characterised in that the backrest (16) for the pile warp (13) is adjustable by means of a drive (59).

12. Arrangement for mounting a warp yarn backrest characterized by a spring assembly (34) on which the backrest is held by brackets (32) having a band like shape and facing with their small surface in weaving direction.

13. Arrangement according to claim 12 characterized in the spring assembly (34) is a package of leaf springs extending transversely to the weaving direction.

14. Arrangement according to claim 12 or 13 characterized in that the backrest (16) is rotatably mounted in the brackets (32).

15. Arrangement according to one of claims 12 to 14 characterized in that a device for monitoring the tension of the warp yarns (13) is provided.

16. Arrangement according to claim 15 characterized by a device (59) for adjusting the position of the backrest (16) and / or the tension of the warp yarns (13).

17. Arrangement according to on of claims 12 to 16 characterized by a stopper element (61) for limiting the movement of the spring assembly (34).