WO2008155105A1

WO2008155105A1 - Support element for a gripper for a gripper weaving machine

Info

Publication number: WO2008155105A1
Application number: PCT/EP2008/004895
Authority: WO
Inventors: Joost Carpentier; Arnold Moerman; Denis Moeneclaey
Original assignee: Picanol N.V.
Priority date: 2007-06-21
Filing date: 2008-06-18
Publication date: 2008-12-24
Also published as: BE1017654A5

Abstract

A support element for a gripper (3, 4) in a gripper weaving machine, the support element (1, 2) comprising an element (17, 18, 19, 20, 42) which is attached by injection-molding to a gripper band (21) and widens the support element (1, 2) at least laterally and the element (17, 18, 19, 20, 42) which widens the support element (1, 2) at least laterally being attached to the gripper band (21) in proximity to the gripper (3, 4).

Description

SUPPORT ELEMENT FOR A GRIPPER FOR A GRIPPER WEAVING

MACHINE

[0001] The invention relates to a support element for moving a gripper in and out of a shed in a gripper weaving machine, the support element comprising a gripper band and a gripper carrying element which is attached to the gripper band and enlarges the support element at least laterally.

[0002] A support element for a gripper of the aforementioned type is known, for example, from EP 0 576 854 Al. In this case, the support element comprises a gripper band and an element which is attached to the gripper band. The gripper band can interact with guide elements which guide the gripper band when the gripper band is moved through the shed. The gripper band, which extends in longitudinal direction, is relatively rigid in lateral direction (transverse direction) , whereas the gripper band is relatively bendable perpendicularly to the aforementioned direction (bending direction) . This allows the gripper band to move through the shed and also to bend around a drive wheel. The element is in this case detachably fastened to the gripper band and/or to the gripper by means of a screwed connection. Such screwed connection is disadvantageous as it can come into contact with the guide elements which guide the gripper band while it is moving through the shed.

[0003] A gripper band comprising a portion which laterally widens the gripper band is known from WO 94/10364, the gripper band and this portion being configured in one piece. A gripper band of this type has the drawback of being difficult to manufacture. A gripper band of the aforementioned type is also known from WO 2006/037618. FR 2541321 discloses attaching an enforcing rib to the upper side of the gripper band. The attachment of an enforcing rib of this type to the - - upper side of a gripper band which is relatively flexible in its bending direction has the drawback that a gripper band of this type buckles in the region of this rib. In order to prevent this buckling, the gripper band is deformed before the bracing rib is attached; however, this deformation can provide only limited compensation for buckling.

[0004] The object of the invention is to manufacture a support element of the aforementioned type in a simple manner. The invention also relates to a support element which has no fastening elements which may cause damage to the guide elements for the support element .

[0005] This object is achieved in that the gripper carrying element is manufactured and directly attached to the gripper band by injection-molding.

[0006) A support element according to the invention has the advantage that it is simple to manufacture and that there are no fastening elements between the element, i.e., the gripper carrying element, and the gripper band which might cause damage to the guide elements for guiding the support element through the shed. Also, the element which widens or broadens the support element at least laterally can be used to protect the warp threads from the guide elements.

[0007] The gripper carrying element is preferably made of plastic material, preferably a thermoplastic polymer which may or may not contain reinforcement fibers .

[0008] According to one embodiment of the invention, the element is attached symmetrically with respect to a longitudinal plane of the support element. In this case, the element is also preferably attached symmetrically with respect to a longitudinal plane of the support element by injection-molding. [0009] According to one embodiment of the invention, the support element comprises an element which widens or enlarges the support element at least laterally and which is directly attached by injection-molding.

[0010] According to one embodiment of the invention, the support element comprises a gripper band having openings which extend from the upper side of the gripper band to the underside of the gripper band and the element which is attached by injection-molding extends through said openings. The provision of a large number of openings is also advantageous to prevent buckling of the element and/or the support element, more particularly to attribute the buckling to the cooling of the heated thermoplastic material that is applied during injection-molding.

[0011] According to one embodiment of the invention, the support element comprising a gripper band having openings which extend from the upper side of the gripper band to the underside of the gripper band and the element comprises a portion which is attached to the upper side of the gripper band, a portion which is attached to the underside of the gripper band and portions which extend through the aforementioned openings to join the aforementioned portions together. Preferably, the element, more particularly the element which is directly attached by injection-molding, is attached symmetrically along a longitudinal plane of the support element, more particularly along a longitudinal axis of the gripper band, thus preventing deformation of the element with respect to this longitudinal plane after injection-molding, more particularly deformation in the bending direction of the support element or of the gripper band. As the support element, more particularly the gripper band, is relatively rigid in the transverse direction, the - - support element offers good resistance to deformation in the transverse direction.

[0012] According to one embodiment of the invention, the gripper band of the support element comprises a plurality, i.e. a relatively large number, of openings through which injection-molded material extends. This has the advantage that the element can be effectively mechanically secured to the gripper band. The mechanical securing is obtained substantially as a result of the injection-molded material which extends through the openings .

[0013] In this case, the element preferably has a substantially U-shaped cross section. Preferably, the legs of the U-shaped cross section are thinner than the thickness of the gripper band where these legs are located. This symmetrical cross section is also advantageous for preventing buckling of the element. A U-shaped cross section of this type is also advantageous for the service life of a support element containing a gripper band of this type and a gripper carrying element of this type, as in this case the support element can be applied until the legs of the U- shaped cross section have completely worn away.

[0014] According to one embodiment of the invention, the element has a length which is merely a fraction of the length of the support element. This is advantageous for preventing deformation, as a short element is less susceptible to buckling. In addition, a short element can easily be configured symmetrically, thus also reducing its susceptibility to buckling.

[0015] According to the invention, the gripper is attached to the element which widens the gripper band at least laterally. In this case, the gripper can be fastened to this element laterally remote from the gripper band, thus allowing the gripper to move through - - the shed at a distance from the guide elements. In this case, a screwed connection for attaching a gripper to the element cannot come into contact with the guide elements, as said screwed connection is not located in the area of the guide elements. This also allows an element made of a less wearproof material to be used, as this element does not come into contact with the guide elements and may accordingly be made of, for example, a thermoplastic material which is less wearproof. A thermoplastic material of this type can also have damping properties, so it is particularly suitable to be applied as an element for connecting a gripper to a gripper band.

[0016] According to a preferred embodiment, the gripper band comprises a portion which laterally widens the gripper band and the element which laterally widens the support element is attached to a portion of the gripper band that laterally widens the gripper band. This allows considerable lateral widening of the support element, more particularly by means of a portion of the gripper band that laterally widens the gripper band and thereabove an element which is laterally attached to this portion.

[0017] Further features and advantages of the invention will emerge from the subsequent description of the exemplary embodiments illustrated in the drawings and from the sub-claims. In the drawings:

Figure 1 is a schematic view of a gripper weaving machine with support elements according to the invention,-

Figure 2 is a perspective view of a support element according to the invention with a gripper; Figure 3 shows a gripper band of a support element according to the invention,-

Figure 4 shows a support element according to the invention;

Figure 5 is a top view of the support element according to Figure 4 ;

Figure 6 is a cross section taken along line VI-VI in Figure 5;

Figure 7 is a cross section taken along line VII-VII in Figure 5 ;

Figure 8 is a cross section taken along line VIII-VIII in Figure 5;

Figure 9 is a longitudinal section along line IX-IX in Figure 5;

Figure 10 shows a support element with a gripper according to Figure 2 while the support element is guided by guide elements,-

Figure 11 is a top view of the support element according to Figure 10,-

Figure 12 is a cross section taken along line XII-XII in Figure 11;

Figure 13 shows a variant support element according to the invention,-

Figure 14 shows a further variant support element according to the invention;

Figure 15 is a top view of the support element according to Figure 14 ,- Figure 16 is a cross section taken along line XVI-XVI in Figure 15;

Figure 17 shows a further variant support element according to the invention;

Figure 18 is a top view of the support element according to Figure 17;

Figure 19 is a cross section taken along line IXX-IXX in Figure 17;

Figure 20 shows a further variant support element according to the invention,- and

Figure 21 shows a further variant support element according to the invention.

[0018] The gripper weaving machine illustrated in Figure 1 comprises two support elements 1, 2 for moving a gripper 3, 4 in and out of a shed, which support elements for example each comprise a gripper band. Each support element 1, 2 is driven by a drive means 5, 6. A first gripper 3, in the form of a feed gripper, takes up a weft thread which is presented and brings it into the region of the center of the shed where a second gripper 4, in the form of a receiver gripper, takes over the weft thread. Subsequently, the taken-up weft thread is advanced by the second gripper 4 to the other side of the shed. The drive means 5, 6 each comprise a drive wheel 7, 8 for driving a support element 1, 2. Each support element 1, 2 is held in contact with the associated drive wheel 7, 8 by means of guide blocks 9, 10. A drive wheel 7, 8 is usually a gear wheel, the teeth of which engage with openings in a support element 1, 2. - -

[0019] The gripper weaving machine further comprises a sley 11 which is driven by means of a drive 13, and on which a reed 12 is mounted. A number of guide elements 14 are attached to the sley 11 to guide a support element 1, 2 while the support element is moved through the shed. Stationary guide elements 15, 16 are also provided outside the region of the shed. When the guide elements 14 which move with the sley 11 are arranged in the extension of the stationary guide elements 15, 16, more particularly when the sley 11 is located substantially in the rearmost position, the support elements 1, 2 are inserted in the shed in the longitudinal direction A and are removed back out of the shed.

[0020] In the embodiment shown in Figures 2 to 12, the support element 1 according to the invention comprises a gripper band 21 and an element 17 which is attached to the gripper band 21 in the region where the gripper 3 is arranged. The gripper 3 is attached to the element 17 which widens the gripper band 21 at least laterally, more particularly which laterally widens the portion 22 of the gripper band 21. The gripper band 21 has a first part 23 which is provided with the wide portion 22. The first part 23 is located in proximity to the gripper 3 and is wider than the second part 24 which during use can be bent at least partly around a drive wheel . The gripper carrying element 17 widens the support element 1 at least laterally, meaning that the support element 1 at the area of the element 17 is wider than the remaining part of the support element 1. In this case, the element 17 widens the wider part 23 of the gripper band 21. In this embodiment, the element 17 has a length which is merely a fraction of the length of the gripper band 21, which length also corresponds substantially to the length of the support element 1. The element 17 has, for example, a length of about 10 cm, whereas the gripper band 21 has a length of at least 250 cm. The narrow part 24 has, for example, a - - width of approximately 7.5 mm and a thickness of approximately 4 mm. The gripper band 21 has in the region of the wider part 23, more particularly in the region of the wider part 23 comprising the portion 22, a width of approximately 12.5 mm and, remote from the element 17, a thickness of approximately 4 mm and, at the level of the portion 22 of the wider part 23 that is located in proximity to the element 17, a thickness of approximately 2 mm. The wider part 23 comprises the portion 22 has, for example, a length of at least 20 cm. In the illustrated exemplary embodiment of Figure 2, the wider part 23 has a length of about 40 cm and the element 17 has a length of approximately 10 cm.

[0021] According to the invention, the gripper carrying element 17 which widens the support element 1 at least laterally is attached to the gripper band 21 by injection-molding, more particularly to the portion 22 of the wider first part 23 of the gripper band 21. In this case, the first part 23 is widened by means of the portion 22. In the embodiment of Figures 2 to 12, the element 17 is manufactured by injection-molding. In this case, the element 17 is shaped by injection- molding while the element 17 is attached to the gripper band 21. This element 17 is made of plastics material, more particularly of a thermoplastic polymer which may or may not contain reinforcement fibers.

[0022] Figure 3 shows a gripper band 21 which can be used to manufacture a support element 1 according to the invention. A gripper band 21 of this type has openings 25 formed in the region of the portion 22 of the part 23. The wider part 23, which is located in proximity to the gripper 3, of the gripper band 21 increases the rigidity of the support element 1 in the region of the gripper 3. Openings 25 of this type can be formed by holes . Figures 4 and 5 show a support element 1, an element 17 being attached to the gripper band 21. - -

[0023] As may be seen in Figures 6 to 9, the element 17, which is attached by injection-molding, of the support element 1 is attached substantially symmetrically with respect to a longitudinal plane 26 of the support element 1. This is advantageous to prevent deformation and buckling of the support element 1. In this case, the gripper band 21 of the support element 1 comprises openings 25 extending from an upper side 27 of the first part 23 of the gripper band 21 to an underside 28 of the first part 23 of the qripper band 21. The upper side 27 of the first part 23 and the underside 28 of the first part 23 form respectively at this location likewise an upper side and an underside of the gripper band 21. In this case, it may be seen from Figure 6 that the portion 22 of the first part 23 in proximity to the element 17 has a smaller thickness than the thickness of the remaining portion of the portion 22 of the first part 23 of the gripper band 21. In this case, the first part 23, remote from the portion 22, has substantially the same thickness as the second part 24 of the gripper band 21.

[0024] Figures 6 to 9 show that the element 17, which is attached by injection-molding, extends through openings 25 in the first part 23 of the gripper band 21, more particularly material of the injection-molded element 17 is located through the openings 25. The openings 25 extend from the upper side 27 to the underside 28 of the portion 22 of the first part 23 of the gripper band 21. In this case, the gripper band 21 of the support element 1 comprises a relatively large number of openings 25 through which injection-molded material extends. Furthermore, the element 17 comprises a portion 31 which is attached to the upper side 27 of the gripper band 21 in the area of the first part 23 and a portion 32 which is attached to the underside 28 of the gripper band 21 in the area of the first part 23. The element 17 comprising portions 31 and 32 has in - - this embodiment a substantially U-shaped cross section. The element 17 also comprises connecting portions 33 which are formed by injection-molded material which extends through the openings 25 not only to join the portions 31 and 32 together but also to fasten the element 17 to the gripper band 21. The provision of a plurality of connecting portions 33 is not only advantageous for attaching and fastening the element 17 to the gripper band 21 but is also advantageous for obtaining a good connection between both, which connection does not cause buckling. Figure 9 likewise shows that the gripper carrying element 17 joins the portion 22 almost seamlessly.

[0025] As may be seen in Figures 10 to 12, the gripper band 21 is guided by guide elements 14 which, for example, are mounted in a known manner on a sley 11. In order to guide the first part 23 and the second part 24 of the gripper band 21, the guide elements 14 can partly surround the gripper band 21 and are for this purpose configured similarly to the guide elements described in WO 2006/037618 or the guide elements described in WO 94/10364. As may be seen in Figure 12, the guide elements 14 hardly guide the thinner portion 22 of the first part 23 and the element 17. The portion 22 widens the gripper band 21 in proximity to the element 17 supporting the gripper 3.

[0026] As may be seen in Figure 2, the gripper 3 can be fastened to the element 17 by a bolted connection

30. A bolted connection 30 of this type does not present an obstacle, as it cannot come into contact with the guide elements 14. Obviously, according to a variation, the gripper 3 can also be adhered to the element using adhesive or even fastened to the element

17 by, for example, ultrasonic welding or in a different manner. [0027] The support element 1 can be injection-molded in a mold. Firstly, the gripper band 21 is for this purpose positioned in the mold and the mold is closed. In this case, the mold is constructed in such a way that there is formed around the gripper band 21 a cavity in which material can be injected in order to shape the element 17. This injection can be carried out under pressure and while the material is being heated. Subsequently, the mold is reopened and the shaped support element 1 can be removed from the mold. Molds for injection-molding are generally known, for example from FR 2541321, and will not be described in greater detail in the present document.

[0028] In the embodiment of Figures 2 to 12, the element 17 is relatively short, simple and can be manufactured using a simple mold. The embodiment of Figure 13 differs from the aforementioned embodiment, as the gripper carrying element 18 which widens the support element 1 at least laterally is configured so as to be relatively long. An embodiment of this type has the advantage that the element 18 is more able to stiffen the end of the support element 1. However, such an element 18 requires precise symmetry to prevent buckling. This embodiment also requires a relatively simple mold which should indeed be larger than the mold for attaching the element 17 from Figures 2 to 12. According to a variation, the portion 22 which widens the gripper band 21 can have the same thickness as the thickness of the remaining portion of the first part 23 of the gripper band 21 or the first part 23 can comprise at the level of the upper side 27 and/or at the level of the underside 28 a portion which may or may not be thinner, for example milled off, and is configured similarly to the portion 22 of the embodiment of Figures 2 to 12.

[0029] Figures 14 to 16 show a further variation wherein a gripper carrying element 19, which widens the support element 1 at least laterally, likewise forms the tip 29 of the support element 1. The manufacture of an element 19 by injection-molding allows a tip 29 having a desired shape, for example a shape suitable for guiding warp threads, easily to be provided on the element 19. This embodiment has the advantage that a gripper band 21 can be used, for example a gripper band 21 comprising a thin lateral portion 22 and a front portion which is almost as thin and is arranged in the extension of the second part 24. This front portion can. for example_., be shaped or profiled by mil ling nff a portion on the upper side and on the underside of the gripper band 21. According to a variation, this thinner portion can also be obtained during manufacture of the gripper band. In this case, a more complex element 19 is attached to the gripper band 21 by injection- molding. This element 19 comprises connecting portions 33 which are attached, as in the embodiment of Figures 2 to 12, in openings 25 and connecting portions 34 which are attached in openings 35.

[0030] Figures 17 to 19 show a further variation in which the gripper carrying element 20 is attached in a slot 36 formed in the gripper band 21. In this case, the gripper band 21 does not comprise any widenings as in the embodiments of Figures 1 to 16. The gripper band 21 also comprises openings 37 extending from the upper side to the underside of the gripper band 21. The element 20 is in this case likewise attached to the gripper band 21 by injection-molding. The element 20 comprises in this case a plurality of collars 38 extending through openings 37 such as holes in the gripper band 21. The element 20 has a somewhat T-shaped cross section. This embodiment requires a more complex mold, provides a tip 29 on the element 20 and requires merely a narrow gripper band 21 which should indeed be provided with a slot 36 and openings 37. In this embodiment, the gripper band 21 itself does not comprise any widenings. The gripper band 21 can have a - - width of approximately 7.5 mm and a thickness of approximately 4 mm.

[0031] The gripper carrying element which widens or broadens the support element at least laterally and which is attached by injection-molding is obviously not limited to an injection-molding by which the gripper carrying element and the attachment to the gripper band are made simultaniously. According to a variation (not shown) , an element which laterally widens the gripper band and which, for example, was shaped beforehand by injection-molding can be attached for this purpose to a gripper band to shape a support element 1 according to the invention. In this case, both the gripper band and the pre-shaped element can be provided with the necessary slots and openings to allow them to be joined together by injection-molding. The portion made of injection-molded material which is located between the gripper band and the element can obviously comprise collars and/or connecting portions which allow both to be fastened to one another.

[0032] Figure 20 shows a variation wherein the support element 1 comprises a gripper carrying element 42 which widens the support element 1 at least laterally and also comprising a tip 29. The injection-molding of the element 42 allows a tip 29 having a desired shape easily to be obtained.

[0033] Figure 21 shows a further variation wherein there is also attached by injection-molding, in addition to the element 17 which is attached to the gripper band 21, a second element 43 which can laterally widen the gripper band 21. This element 43 can consist of an injection-molded element.

[0034] It will be clear that, prior to injection- molding, an adhesive, such as a glue, can be attached - - to the gripper band 21 to allow the provision of an adhesive connection between the gripper band 21 and an element 17, 18, 19, 20 or 42 which is attached to the gripper band 21 by injection-molding. It will, however, be clear that the collars 38 and/or the connecting portions 33 can be adequately mechanically secured, thus obviating the need for an adhesive connection. According to a further variation, an element which is attached to a gripper band by injection-molding can also be fastened to the gripper band by means of, for example, ultrasonic welding in order to additionally secure the fastening of the element to the gripper band.

[0035] A support element 1 according to the invention, which comprises a gripper band 21 and which comprises an element 17, 18, 19, 20, 39, 40 and 42 which widens the support element 1 at least laterally, which is manufactured by injection-molding and which is attached to the gripper band 21, has the advantage of allowing a support element 1, which is wider than the gripper band 21, easily to be obtained. This allows a gripper 3 to be fastened to an edge of a support element 1 in a simple manner. This fastening can be carried out by adhesion, by mechanical connecting systems, by ultrasonic welding and the like.

[0036] An attached element 17, 18, 19, 20, and 42, which widens the support element 1 at least laterally in the region of the support element 1 where a gripper

3 is attached, has the advantage that the support element 1 can easily be widened in the region of the gripper 3 in order to be able to attach a gripper 3 in a simple manner.

[0037] The support element 2 as shown in Figure 1 can be configured similarly to the support element 1 as shown in the embodiments of Figures 1 to 21. Obviously, in this case, the support element 2 can be configured - - substantially mirror-symmetrically on the support element 1.

[0038] It will be clear that the gripper band 21 is not limited to a relatively bendable or flexible gripper band which can be bent around a drive wheel 7.

According to a variation (not shown) , the gripper band can likewise be relatively rigid in its configuration, more particularly act as a gripper rod, and be guided tangentially along a drive wheel in order to be driven by the drive wheel .

[0039] A gripper band according to the invention represented in the claims is not limited to the exemplary embodiments which have been illustrated and described but can likewise include variations and combinations thereof which fall under the scope of the claims .

Claims

1. Support element for a gripper (3, 4) for a gripper weaving machine which support element (1 , 2) comprises a gripper band (21 ) and a gripper carrying element (17, 18, 19, 20, 42) which is attached to the gripper band (21 ) and which widens the support element at least laterally, characterized in that the gripper carrying element (17, 18, 19, 20, 42) is manufactured and attached to the gripper band (21 ) by injection-moulding.

2. Support element according to claim 1 , characterized in that the gripper carrying element (17, 18, 19, 20, 42) is made of plastic material, preferably of a thermoplastic material such as a polymer.

3. Support element according to claim 1 or 2, characterized in that the gripper carrying element (17, 18, 19, 20, 42) is made of plastic material comprising reinforcing fibers.

4. Support element according to any one of claims 1 to 3, characterized in that the end of the gripper band (21 ), to which the gripper carrying element (17, 18, 19, 20, 42) is attached, is shaped.

5. Support element according to claim 4, characterized in that the gripper band (21 ) in the area of its end to which the gripper carrying element (17, 18, 19, 20, 42) is attached, is provided with holes (25, 35) preferably extending from the upper side (27) to the lower side (28) of the gripper band (21 ).

6. Support element according to one of claims 1 to 5, characterized in that the gripper band (21 ) in the area of its end to which the gripper carrying element (17, 18, 19, 20, 42) is attached, is provided with a lateral portion (22).

7. Support element according to claim 5 or 6, characterized in that the portion (22) of the gripper band (21 ) having a reduced thickness is provided with holes (25, 35).

8. Support element according to any one of claims 5 to 7, characterised in that portions (31 , 32) of the gripper carrying element (17, 18, 19, 42) in the area of the holes (25, 35) are connected to each other by material (33) injected into the holes (25, 35).

9. Support element according to any one of claims 1 to 8, characterized in that the gripper carrying element (17, 18, 19, 20, 42) extends laterally from the gripper band (21 ).

10. Support element according to any one of claims 1 to 9, characterized in that the injection-moulding gripper carrying element (10, 20, 42) forms the front tip (29) of the supporting element (1 ,2).