Weaving frame for a weaving machine.

[0001] The invention relates to a transverse beam for a weaving frame, a weaving frame provided with a transverse beam of this type and a method for producing a transverse beam of this type.

[0002] With weaving machines, a weaving frame is used to form a shed. A weaving frame is driven by a drive mechanism, such as a dobby, a cam box, an eccentric mechanism or any other drive mechanism. The drive mechanism may impose a desired movement path to the weaving frame.

[0003] With fast running weaving machines, a weaving frame is usually subjected to considerable mechanical loads. These loads limit the maximum admissible weaving speed at which a weaving frame can be used without risking fractures. It is known to reinforce a weaving frame in order to reduce the risk of fractures of weaving frames or in order to increase the maximum admissible weaving speed. BE 525339 describes a weaving frame in which both transverse beams comprise a reinforcing profile. In one embodiment, a substantially U-shaped reinforcing profile is provided both at the top and at the bottom of the weaving frame. US 3754577 describes a weaving frame with transverse beams which are substantially formed by a hollow light-metal transverse profile to which a plurality of reinforcing profiles are bonded.

[0004] It is an object of the invention to provide an improved transverse beam for a weaving frame which is sufficiently strong for allowing high weaving speeds or high loads.

[0005] In order to achieve this object, a transverse beam according to the invention comprises a transverse profile provided with a collar to which a substantially U-shaped reinforcing profile is bonded, in which the collar can be fitted inside the cavity in the U-

shaped reinforcing profile, characterized in that the transverse beam comprises positioning devices for positioning the reinforcing profile and the transverse profile relative to one another, which positioning devices are formed by the ends of the legs of the U-shaped reinforc- ing profile and guides arranged next to the collar with which the ends of the legs can co-operate, and in that the transverse beam contains adhesive which extends between the reinforcing profile and the transverse profile.

[0006] The invention makes it possible to improve the bonding connection between a transverse profile and a reinforcing profile by conveniently providing the adhesive between the two. In this case, also the effect is achieved that the thickness of the adhesive between each leg of the U-shaped reinforcing profile and the collar of the transverse profile is substantially equal. This is achieved by accurately positioning both relative to one another, more particularly by centering both relative to one another. In this way, the reinforcing profile can be bonded to the transverse profile under ideal circumstances, more particularly both can be bonded to one another while being perfectly positioned relative to one another. The invention also allows to press with great force the transverse profile and the reinforcing profile against one another during bonding in accordance with their vertical direction. This makes it possible to achieve a straight and bonded transverse beam, that is to say a transverse beam which will assume the substantially straight shape of the reinforcing profile as a result of the transverse profile being deformed. This straight shape can also be retained after the transverse profile has been connected to the reinforcing profile. Due to a transverse beam comprising an abovementioned reinforcing profile bonded to a transverse profile, the weaving frame can be very wide, without any risk of fracture or significant bending. Such a transverse beam according to the invention is also strong.

[0007] According to an embodiment, a transverse profile is formed by a hollow transverse profile made from a light metal, for

example in aluminum or in an aluminum alloy. According to an embodiment, a reinforcing profile is formed by a fiber-reinforced synthetic material, for example a carbon fiber-reinforced synthetic material, a glass fiber-reinforced synthetic material or a Kevlar fiber- reinforced synthetic material. This makes it possible to produce a light transverse beam of high strength.

[0008] According to an embodiment, the transverse profile and the reinforcing profile are bonded to one another using an adhesive, for example a glue based on epoxy resin, acrylate or any other adhesive which is suitable for forming a good connection between a light metal and a fiber-reinforced synthetic material.

[0009] According to an embodiment, the reinforcing profile is attached to the transverse profile so that, with a weaving frame, the reinforcing profile is at the top and/or at the bottom of the weaving frame. As a result, the reinforcing profile is arranged on the far side of the transverse profile, situated opposite the side of the transverse profile where the heddle bar is attached to the transverse profile. In this way, the reinforcing profile is fitted in an advantageous location in order to impart rigidity and strength to the transverse beam and thus also to the weaving frame.

[0010] The invention also relates to a method for producing a transverse beam for a weaving frame, which method comprises positioning the transverse profile and the reinforcing profile relative to one another by pressing the transverse profile and the reinforcing profile against one another until both are positioned relative to one another by means of positioning devices of the transverse beam while both are being bonded to one another.

[0011] This method makes it possible to apply the adhesive between the transverse profile and the reinforcing profile in an optimum manner. This method also makes it possible to produce a sub- stantially straight transverse beam. The latter is achieved by press-

ing the positioning devices against one another during bonding. This also makes it possible to prevent a displacement of the transverse profile and the reinforcing profile relative to one another during bonding.

[0012] In order to illustrate the features and further advantages of the invention more clearly, the invention will be explained in more detail below with reference to drawings of exemplary embodiments, in which: fig. 1 diagrammatically shows a weaving frame according to the invention; fig. 2 shows a cross section along line H-Il of a weaving frame according to fig. 1 ; fig. 3 shows an enlarged view of a part of the cross section from fig. 2; fig. 4 shows a variant of fig. 3.

[0013] Fig. 1 shows a weaving frame 1 which comprises a top transverse beam 2 and a bottom transverse beam 3. The transverse beams 2 and 3 are connected to one another by two lateral supports 4 and 5. These connections are achieved by means of corner joints 6, 7, 8 and 9, which, for example, are of similar design to those described in DE 19816950 and EP 659917. A top heddle bar 10 is arranged near the top transverse beam 2, while a bottom heddle bar 11 is arranged near the bottom transverse beam 3. In addition, a damping element 13 and 14 for the heddles 12 can be arranged near each transverse beam 2 and 3, which damping element 13 and 14 is of similar design, for example, to that described in WO 01/48284. The heddles 12 are arranged between both heddle bars 10 and 11 and comprise a thred eye 15 for guiding a warp thread.

[0014] Furthermore, it is possible to arrange known guide elements 16 on each transverse beam 2, 3. In addition, a threaded rod 17 is arranged near each lateral support 4 and 5, comprising a cou-

pling element 18 for connecting the threaded rod 17 with a drive mechanism (not shown). The threaded rod 17 also comprises an adjustment unit 19 for adjusting the threaded rod 17 relative to a lateral support 4 or 5. Such a threaded rod 17 and a drive mechanism are, for example, known from EP 520540. The weaving frame 1 , as illustrated in fig. 1 , comprises a reinforcing profile 20 which is connected to the transverse beam 2 and a reinforcing profile 21 which is connected to the transverse beam 3.

[0015] As illustrated in fig. 2, the transverse beam 2 comprises a hollow transverse profile 22 to which a heddle bar 10 is attached in a known manner. This hollow transverse profile 22 comprises a plurality of cavities 23. According to the invention, a reinforcing profile 20 is attached near the far side 24 of the hollow transverse pro- file 22 in order to provide a reinforced transverse beam 2. This far side 24 is situated opposite the far side 25 of the transverse profile 22 where the heddle bar 10 is located. A damping element 13 is also attached to this transverse profile 22 in a known manner.

[0016] The hollow transverse profile 22 is made from light metal, such as aluminum, an alloy based on aluminum, another light metal or an alloy based on another light metal. A transverse profile 22 of this type can be drawn in a known manner. A hollow transverse profile 22 is relatively light and suitable for use at high weav- ing speeds. However, a hollow transverse profile 22 of this type can be reinforced according to the invention with a reinforcing profile 20 so that it can be used at even higher weaving speeds. A reinforcing profile 20 consists of a material having a relatively high strength. Such a material is, for example, a synthetic material and comprises, for example, carbon fibers, Kevlar fibers, glass fibers or other high- strength fibers. As a result, the reinforcing profile 20 is relatively and significantly stronger than the transverse profile 22.

[0017] According to the embodiment shown in fig. 3, the rein- forcing profile 20 is formed by a substantially U-shaped profile which

comprises a base element 26, two legs 27 and 28 and a cavity 29 between the two legs 27 and 28. The far side 24 of the transverse profile 22 comprises a collar 30 and two guides 31 and 32 which are provided on both sides of said collar 30. The collar 30 in this case has substantially parallel lateral faces 46, 47 and a top face 48 which is positioned substantially perpendicularly to the lateral faces 46, 47. At the cavity 29, the inner faces 49, 50 of the legs 27 and 28 are substantially parallel and the base face 51 of the cavity 29 is substantially perpendicular to the inner faces 49, 50. In the embodi- ment shown, the guides 31 and 32 consist of slots which extend in the width direction B (fig. 1 ) of the transverse beam 2. The ends 33 and 34 of the legs 27 and 28 of the U-shaped reinforcing profile 20 and the guides 31 and 32 of the transverse profile 20 form positioning devices 35 and 36 for positioning and/or centering the reinforc- ing profile 20 and the transverse profile 22 relative to one another in such a manner that adhesive, such as glue, can be applied between both in an ideal manner. The far side 24 of the transverse profile 22 has a collar 30 which can be arranged in the cavity 29 of the U- shaped reinforcing profile 20 so that the positioning devices 35 and 36 can engage with one another. In this way, it is possible to position the reinforcing profile 20 perfectly relative to the transverse profile 22 and the adhesive 37, 38, 39 can extend uniformly between the reinforcing profile 20 and the transverse profile 22.

[0018] A possible method for producing a transverse beam 2 according to the invention comprises steps which are described below. An adhesive 37, 38 is applied near the guides 31 , 32 and an adhesive 39 is applied near the cavity 29. The reinforcing profile 20 is arranged on the transverse profile 22 according to direction H in a position as shown in fig. 2, so that both can be positioned relative to one another. The reinforcing profile 20 and the transverse profile 22 are subsequently pressed together more firmly, so that both are positioned more accurately relative to one another by means of the positioning devices 35 and 36. For this pressing together, use can be made of a pressing device, for example a classic pressing device

similar to that described in US 3754577. Here, the transverse profile 22 and the reinforcing profile 20 are accurately aligned relative to one another and also accurately centered relative to one another, so that the collar 30 is positioned centrally in the cavity 29 and the ends 33, 34 of the legs 27, 28 are accurately centered in the guides 31 , 32. To this end, the shape of the ends 33, 34 is also adapted to the shape of the guides 31 , 32, for example the shape of the ends 33, 34 is wedge shaped and the shape of the guides 31 , 32 is opposite thereto.

[0019] This results in the adhesive 37, 38, 39 being distributed accurately in the cavities present between the reinforcing profile 20 and the transverse profile 22. Subsequently, the adhesive 37, 38, 39 can thermally cure, so that the two parts are bonded together per- fectly. The guides 31 and 32 of the transverse profile 22 and the cavity 29 of the reinforcing profile 20 are preeminently suitable as a reservoir for applying and dosing the adhesive 37, 38, 39 using known means. Applying the adhesive 37, 38, 39 in these locations also makes it possible to maneuver the reinforcing profile 20 relative to the transverse profile 22 without any great risk that the operator will come into contact with the adhesive 37, 38, 39. The option of gradually applying the reinforcing profile 20 onto the transverse profile 22 according to direction H after the adhesive 37, 38, 39 has been applied also offers the advantage that the adhesive 37, 38, 39 can spread uniformly. As a result, the risk of adhesive being removed or of air bubbles developing in the adhesive is avoided. When the reinforcing profile 20 is pressed onto the transverse profile 22 in a pressing device, the legs 27 and 28 of the U-shaped reinforcing profile 20 are in this case pressed into the associated guides 31 and 32 of the transverse profile 22.

[0020] Usually, the reinforcing profile 20 has a greater degree of straightness than the transverse profile 22, which is for example a drawn light-metal profile. The beveled shape of the ends 33, 34 of the legs 27, 28 and the substantially corresponding beveled shape

O of the contact surfaces of the guides 31 and 32 force the transverse profile 22 to follow the straightness of the stronger reinforcing profile 20 unet pressure in the direction H. Thus, the resulting straightness of the assembled transverse beam 2 is substantially determined by the straightness of the transverse profile 22. In addition, the beveled shapes promote a uniform distribution of the adhesive 37, 38, 39 between the reinforcing profile 20 and the transverse profile 22.

[0021] The beveled shape of the positioning devices 35 and 36 also promotes centering of the reinforcing profile 20 relative to the transverse profile 22 during pressure in the direction H, which means, for example, that the reinforcing profile 20 also centers itself toward a center line 43 of the transverse beam 2. As can be seen in figure 3, the side surfaces 41 and 42 of the reinforcing profile 20 and the side surfaces 44, 45 of the transverse profile 22 are substantially parallel to one another and substantially parallel to the center line 43. The method according to the invention makes it possible in this case to choose the dimensions of the reinforcing profile 20 in direction D within a wide range and to prevent the side surfaces 41 , 42 extending beyond the side surfaces 44, 45. The latter is advantageous if a number of weaving frames 1 are arranged close together in the direction D and in this way prevents a reinforcing profile 22 of a weaving frame from being torn off by a weaving frame arranged next to the respective weaving frame. To this end, it is advanta- geous if the transverse beams 2 and 3 are exactly straight and if the reinforcing profile 20 is well centered relative to the corresponding transverse profile 22.

[0022] The curing of the adhesive, for example the thermal cur- ing with an abovementioned method, may be effected while a small relative movement of the reinforcing profile 20 and the transverse profile 22 takes place and without interfering with the uniform distribution of the adhesive 37, 38, 39. A straight reinforcing profile 20 in this case makes it possible to produce a straight transverse beam 2, which is advantageous mainly with weaving frames 1 which are of a

relatively great width.

[0023] As can be seen in fig. 3, the reinforcing profile 20 only virtually contacts the transverse profile 22 near the beveled contact surfaces 52, 53 of the positioning devices 35 and 36. The adhesive 37, 38 is in this case substantially in a space between one end 33, 34 of the legs 27, 28 of the reinforcing profile 20 and the base of the guides 31 and 32 of the transverse profile 22, while the adhesive 39 is in the space between the collar 30 and the cavity 29. These spaces make a relative movement of the transverse profile 22 with respect to the reinforcement profile 20 possible during tensioning in a direction H, both in direction H and in direction D. This movement is only delimited by the beveled contact surfaces of the positioning devices 35, 36. Such shapes hardly change the volume and the di- mensions of the adhesive 37, 38, 39 to be applied with relative movements of the reinforcing profile 20 with respect to the transverse profile 22. This leads to a reliable and reproducible adhesive connection which is suitable for high-quality mass production.

[0024] Fig. 4 shows a variant in which the side faces 54, 55 of the collar 40 diverge slightly in a direction away from the side 24. The inner faces 56, 57 of the legs 27, 28 at the cavity 29 in this case converge towards one another in the direction of the ends 33, 34 of the legs 27, 28. This makes it possible to attach the reinforcing pro- file 20 even more tightly to the transverse profile 22, as a mechanical anchoring force is present in addition to the force of the adhesive 39. This anchoring force is mainly achieved by the orientation of the side faces 54, 55 of the collar 40, the orientation of the inner faces 56, 57 of the legs 27, 28 of the substantially U-shaped reinforcing profile 20 and the adhesive 39 which is pressed between the side faces 54, 55 of the collar 40 and the inner faces 56, 57 of the legs 27, 28. As this adhesive 39 is also clamped between the collar 40 and the legs 27, 28, an even tighter connection is produced. In this case, the guides 31, 32 and the ends 33, 34 of the legs 27, 28 also provide for correct alignment and correct centering of the reinforcing

profile 20 relative to the transverse profile 22. In the embodiment of fig. 4, the adhesive surface is also slightly larger than with the embodiment of fig. 3. The method for attaching the reinforcing profile 20 from fig. 4 is similar to the method for attaching the reinforcing profile 20 from fig. 3.

[0025] The transverse beam 3 with reinforcing profile 21 can be produced and executed in a similar manner to the transverse beam 2 with reinforcing profile 20. In this case, the reinforcing profile 21 is for example provided at the bottom of the weaving frame 1 , i.e. at the far side of the transverse beam 3 which is opposite the side where the heddle bar 11 is situated. Analogously, the transverse beam 3 comprises a hollow transverse profile as the transverse profile 2 to which the reinforcing profile 21 is attached.

[0026] The adhesive may consist of a commercially available epoxy resin, an adhesive based on acrylate, a glue or any other adhesive which can bond an abovementioned transverse profile and an abovementioned reinforcing profile 20, 21 together. In a most simple embodiment, the transverse profile 22 is formed, for example, by an extruded aluminum transverse profile, while the reinforcing profile 20 is formed by a synthetic material containing carbon fibers.

[0027] The positioning devices 35, 36 are also not limited to the embodiments shown, which use beveled shapes and/or contact surfaces, but may also comprise other shapes and/or contact surfaces, such as rounded shapes and/or contact surfaces. The positioning devices 35, 36 are preferably formed by profiled ends 33, 34 of the legs 27, 28 of the reinforcing profile 20, 21 and by profiled guides 31 , 32 of the transverse profile 22, which make it possible for a transverse profile 22 and a reinforcing profile 20, 21 to be positioned or centered relative to one another.

[0028] A reinforcing profile 20, 21 according to the invention

^ also offers the advantage that the legs 27, 28 are not subjected to a lateral load when the reinforcing profile 20, 21 is attached to a transverse profile 22 of a transverse beam 2, 3. In addition, the above- mentioned legs 27, 28 are reinforced by the collars 30, 40 after be- ing attached or bonded so that the lateral load is reduced.

[0029] Obviously, the transverse beam, the weaving frame and the method according to the invention are not limited to the embodiments described by way of example and illustrated in the fig- ures, but may be designed in accordance with different variants and in accordance with different combinations of the abovementioned illustrated embodiments without departing from the scope of the invention.