Tensioning device, particularly for textile machines

Abstract

A tensioning device (1), particularly for textile machines and the like, characterized in that it comprises: - a supporting structure (2) associable with a textile machine or the like (100) at its inlet of the warp yarns (3, 4) of a fabric to be woven; - a main roller (6) of the motorized type and rotatably associated with the supporting structure (2) about a main axis of rotation (6a) in a direction which is transverse to the crossing direction of the warp yarns (3, 4) in the textile machine or the like (100); - a first guiding roller (8), which is kinematically associated with the supporting structure (2) and is movable between a weaving configuration, in which it is arranged behind, parallel to and in contact with, respectively, the main roller (6) with respect to the crossing direction of the warp yarns (3, 4) in the textile machine or the like (100), so as to be integral in rotation with the main roller (6), and a threading configuration, wherein it is spaced from the main roller (6) to allow the threading of the warp yarns (3, 4) in the textile machine or the like (100); pair of eccentric levers (12), which are rotatably associated with the main roller (6) about an eccentric axis of rotation (12a) that is parallel with respect to the main axis of rotation (6a) and rotatably support the first guiding roller (8), the first guiding roller (8) being movable between the weaving configuration and the threading configuration as a result of the rotation of the eccentric levers (12) about the eccentric axis of rotation (12a) by virtue of means (13) of the motorized type for moving the eccentric levers (12).

Description

[0001] The present invention relates to a tensioning device, particularly for textile machines and the like.

[0002] Currently, the devices normally used for warp tensioning in the textile field provide for the movement of the various yarn guiding rollers by virtue of linear and rectilinear movements, which are usually not automated, manual and with the aid of load handling systems which are external to the production machine, such as, for example, overhead cranes or hoists.

[0003] In particular, in the industrial textile machine sector, for so-called "heavy" metallic and synthetic technical fabrics, the fabrics must be tensioned with much higher tensions than in traditional weaving processes, and the various rollers used, as well as the machine components, have considerable dimensions and weights in order to withstand the stresses generated during the weaving process.

[0004] This leads to the use of several operators and machines at the same time in order to be able to "thread" / prepare the loom for weaving.

[0005] More specifically, tensioning devices of the known type are usually composed of two or three rollers that cause the warp yarns to follow an S-shaped path in order to tension them.

[0006] The S-shaped paths remain very closed, because they move with linear systems that allow the rollers to move in straight lines as mentioned above.

[0007] The fact that there are closed spaces means that there is little room for the yarns to pass between the various rollers during the threading operations.

[0008] Moreover, the rectilinear movement does not allow the yarns to be sufficiently "pinched" between the rollers, unless three rollers are used and kept very close together, which however further worsens the drawback of the lack of space mentioned above.

[0009] The aim of the present invention is to provide a tensioning device, particularly for textile machines and the like, capable of overcoming the abovementioned drawbacks.

[0010] Within this aim, an object of the present invention is to provide a tensioning device particularly suitable for industrial weaving with heavy fabrics.

[0011] An object of the present invention is to provide a tensioning device capable of ensuring correct tension of the warp yarns, while at the same time allowing to perform the threading operations easily.

[0012] A further object of the present invention is to provide a tensioning device capable of giving the greatest assurances of reliability, efficiency and operation.

[0013] A further object of the present invention is to provide a tensioning device which can be manufactured using technology known in the technical field concerned and therefore can produced at competitive costs.

[0014] This aim, as well as these and other objects that will become more apparent hereinafter, are achieved by a tensioning device, particularly for textile machines and the like, according to claim 1.

[0015] Further characteristics and advantages of the invention will become more apparent from the description of a preferred but not exclusive embodiment of a tensioning device, particularly for textile machines and the like, illustrated by way of non-limiting example with the aid of the accompanying drawings, wherein: Figure 1 is a front perspective view of a tensioning device according to the invention, in its weaving configuration; Figure 2 is a top plan view of the tensioning device shown in Figure 1; Figure 3 is a rear perspective view of the tensioning device shown in the preceding figures; Figure 4 is a bottom plan view of the tensioning device shown in the preceding figures; Figure 5 is a lateral elevation view, taken from the left, of the tensioning device shown in the preceding figures; Figure 6 is a lateral elevation view, taken from the right, of the tensioning device shown in the preceding figures; Figure 7 is a sectional view of the tensioning device shown in the preceding figures, taken along the sectional plane VII-VII shown in Figure 5; Figure 8 is a sectional view of the tensioning device shown in the preceding figures, taken along the sectional plane VIII-VIII shown in Figure 6; Figure 9 is a lateral elevation view of the tensioning device shown in the preceding figures, applied to a textile machine and partially in phantom lines in order to show the internal components, as well as the path of the warp yarns; Figures 10 and 11 are two lateral elevation views of the tensioning device shown in Figure 9, showing in sequence the transition from said weaving configuration to a threading configuration.

[0016] With reference to the figures, the tensioning device, particularly for textile machines and the like, is generally designated by the reference numeral 1 and comprises a supporting structure 2 which is associable with a textile machine or the like, generally designated by the reference numeral 100, at its inlet of the warp yarns of a fabric to be woven.

[0017] More specifically, in the proposed embodiment the abovementioned warp yarns arrive from two separate spools, such as to form upper warp yarns 3 and lower warp yarns 4.

[0018] Moreover, as will be better described hereinafter, the supporting structure 2 comprises two lateral shoulders 2a and 2b arranged laterally to the rollers of the tensioning device 1 and configured to be rested directly on the ground, by means of appropriate supports 5, in front of the textile machine or the like 100 at the inlet of the warp yarns 3 and 4.

[0019] Conveniently, the tensioning device 1 comprises: a main roller 6 of the motorized type, for example by means of a servomotor with a reduction unit 7, rotatably associated with the supporting structure 2 about a main axis of rotation 6a in a direction which is transverse to the crossing direction of the warp yarns 3 and 4 in the textile machine or the like 100; a first guiding roller 8, for example of the rubber-coated type, which is kinematically associated with the supporting structure 2 and is movable between a weaving configuration, in which it is arranged to the rear, parallel to and in contact with, respectively, the main roller 6 with respect to the crossing direction of the warp yarns 3 and 4 in the textile machine or the like 100 so as to be integral in rotation with the main roller 6, and a threading configuration, in which the first guiding roller 8 is spaced from the main roller 6 to allow the threading of the warp yarns 3 and 4 in the textile machine or the like 100; a second guiding roller 9, for example of the chromium-plated type, also kinematically associated with the supporting structure 2 and movable between the weaving configuration, in which it is arranged frontally and parallel to the main roller 6 with respect to the crossing direction of the warp yarns 3 and 4 in the textile machine or the like 100, and the threading configuration, in which the second guiding roller 9 is spaced from the main roller 6 to allow the threading of the warp yarns 3 and 4 in the textile machine or the like 100.

[0020] Conveniently, each lateral shoulder 2a and 2b is provided with a through hole for mounting a respective bearing adapted to rotatably support the shaft of the main roller 6, and the servomotor with the reduction unit 7 is located externally to one of said lateral shoulders.

[0021] Equally conveniently, both the first guiding roller 6 and the second guiding roller 9 are freely rotatable, respectively, about a first guiding rotation axis 6a and about a second guiding rotation axis 9a.

[0022] In the proposed embodiment, during the weaving configuration, the main roller 6 actuates the traction of the warp yarns 3 and 4 by directly moving the first guiding roller 8 and indirectly moving the second guiding roller 9 by means of the traction of the warp yarns 3 and 4.

[0023] In fact, there are two first toothed profiles 10, which are formed externally and laterally to the main roller 6 and are integral in rotation therewith about the main axis of rotation 6a, and two second toothed profiles 11, which are formed externally and laterally to the first guiding roller 8 and are integral in rotation therewith about the first guiding rotation axis 8a.

[0024] Conveniently, the first and second toothed profiles 10 and 11 are configured for mutual meshing in said weaving configuration.

[0025] According to the invention, the tensioning device 1 comprises a pair of eccentric levers 12 which are rotatably associated with the main roller 6 about an eccentric axis of rotation 12a which is parallel to the main axis of rotation 8a.

[0026] In Figures 9 to 11, the eccentricity between the eccentric axis of rotation 12a and the main axis of rotation 8a is represented by the dimension "e".

[0027] Advantageously, the eccentric levers 12 rotatably support the first guiding roller 9 so that it is movable between said weaving configuration and said threading configuration following the rotation of the eccentric levers 12, and are configured and shaped, respectively, to interfere and engage with the second guiding roller 9 in the transition between said weaving configuration and said threading configuration so as to completely clear the area in front of the main roller 6 from the second guiding roller 9.

[0028] Also according to the invention, means 13 of the motorized type are provided for moving the eccentric levers 12.

[0029] In fact, the eccentric levers 12 are integral in rotation with two respective toothed wheels 14 which are idle with respect to the main roller 6 about the eccentric axis of rotation 12a, and the movement means 13 comprise a motorized actuation shaft 15 equipped with two pinions 16 which mesh with the toothed wheels 14 for the rotation of the eccentric levers 12 about the eccentric axis of rotation 12a.

[0030] More specifically, the actuation shaft 15 is supported by the lateral shoulders 2a and 2b by means of bearings and is driven by a servomotor with a reduction unit 17.

[0031] In this way it is possible to provide the transition of the first guiding roller 8 from said weaving configuration to said threading configuration and vice versa.

[0032] In the proposed embodiment, inside each lateral shoulder 2a or 2b there is a circular centering device 18 which is eccentric with respect to the main axis of rotation 6a and supports a bushing 19 on which the respective sprocket 14 meshing with the respective pinion 16 is installed in an idle manner.

[0033] This freedom of rotation is provided by virtue of the fact that each sprocket 14 is associated with the respective bushing 19 by means of a plastic slider / bearing.

[0034] In this way, each bushing 19 acts as a support for the respective sprocket 14.

[0035] Moreover, in each bushing there is an eccentric discharge hole 20 for the "free" passage of the pivot of the main roller 6.

[0036] Advantageously, the second guiding roller 9 is rotatably associated with the supporting structure 2, i.e., with the lateral shoulders 2a and 2b, by means of two supporting elements 21 which are associable with the supporting structure 2 in a removable manner so as to allow the roller to be released from the supporting structure 2 in the transition from the weaving configuration to the threading configuration and allow the repositioning of the second guiding roller 9 on the supporting structure 2 in the transition from the threading configuration to the weaving configuration.

[0037] In fact, the eccentric levers 12 each comprise an end portion 22 which is substantially shaped like a cradle and is adapted to engage and support the second guiding roller 9, at the shaft 23 of the second guiding roller 9.

[0038] Such end portion 22 is conveniently provided with a substantially U-shaped removable fixing element 24, adapted to temporarily retain the second guiding roller 9 to the eccentric levers 12.

[0039] The operation of the tensioning device 1, according to the invention, is described hereinafter.

[0040] Starting from the weaving configuration shown in Figure 9, by actuating the actuation shaft 15 the eccentric levers 12 rotate about the eccentric axis of rotation 12a, causing the first guiding roller 8 to perform an elliptical movement about the main axis of rotation 6a.

[0041] Once the eccentric levers 12 have reached the second guiding roller 9 with their end portions 22, as shown in Figure 10, they engage the shaft 23 of the second guiding roller 9.

[0042] At this point, the operator stops the machine in order to retain the shaft 23 to the eccentric levers 12 by means of the fixing elements 24 and release the second guiding roller 9 from the supporting structure 2 by unscrewing the supporting elements 21 from the lateral shoulders 2a and 2b.

[0043] Once these operations have been carried out, by rotating the eccentric levers 12 clockwise, with respect to the figures shown, the guiding rollers 8 and 9 are moved away from the main roller 6, completely clearing the region for threading the warp yarns 3 and 4 and allowing them to be easily threaded into the textile machine 100, passing through the tensioning device 1.

[0044] Vice versa, by turning the eccentric levers 12 counterclockwise, with respect to the figures shown, the guiding rollers 8 and 9 are moved back closer to the main roller 6.

[0045] Similarly to what has been described above, in an intermediate position of the stroke between the threading configuration and the weaving configuration, the operator stops the machine to release the second guiding roller 9 from the eccentric levers 12 and retain it to the lateral shoulders 2a and 2b.

[0046] Conveniently, the placement of the second guiding roller 9 in the intermediate position, shown in Figure 10, is facilitated by the presence of two abutments 25 for the supporting elements 21.

[0047] Continuing with the stroke, once the two rollers 6 and 8 are in mutual contact they mesh with each other by means of the gear systems constituted by the toothed profiles 10 and 11, mounted integral with them, whose meshing is ensured by the fact that the first guiding roller 8 is free to rotate on its own axis.

[0048] In this way, the warp yarns 3 and 4 are subjected to optimum tension thanks to the elliptical movement described above.

[0049] In practice it has been found that the tensioning device according to the present invention achieves the aim and the intended objects, allowing the warp yarns to be tensioned optimally and, at the same time, facilitating threading operations.

[0050] The tensioning device thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims.

[0051] All the details may furthermore be replaced with other technically equivalent elements.

[0052] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

[0053] The disclosures in Italian Patent Application No. 102024000017275 from which this application claims priority are incorporated herein by reference.

[0054] Where technical features mentioned in any claim are followed by reference signs, such reference signs have been inserted for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A tensioning device (1), particularly for textile machines and the like, characterized in that it comprises: - a supporting structure (2) associable with a textile machine or the like (100) at its inlet of the warp yarns (3, 4) of a fabric to be woven; - a main roller (6) of the motorized type and rotatably associated with said supporting structure (2) about a main axis of rotation (6a) in a direction which is transverse to the crossing direction of said warp yarns (3, 4) in said textile machine or the like (100); - a first guiding roller (8), which is kinematically associated with said supporting structure (2) and is movable between a weaving configuration, in which said first guiding roller (8) is arranged behind, parallel to and in contact with, respectively, said main roller (6) with respect to the crossing direction of said warp yarns (3, 4) in said textile machine or the like (100), so as to be integral in rotation with said main roller (6), and a threading configuration, wherein said first guiding roller (8) is spaced from said main roller (6) to allow the threading of said warp yarns (3, 4) in said textile machine or the like (100); said first guiding roller (8) being freely rotatable about a first axis of rotation for guiding (6a); characterized in that it comprises: - a pair of eccentric levers (12), which are rotatably associated with said main roller (6) about an eccentric axis of rotation (12a) that is parallel with respect to said main axis of rotation (6a) and rotatably support said first guiding roller (8); said first guiding roller (8) being movable between said weaving configuration and said threading configuration as a result of the rotation of said eccentric levers (12); and - means (13) of the motorized type for moving said eccentric levers (12).

2. The tensioning device (1) according to claim 1, characterized in that it comprises a second guiding roller (9) which is kinematically associated with said supporting structure (2) and is movable between said weaving configuration, in which said second guiding roller (9) is placed in front of and parallel to said main roller (6) with respect to the crossing direction of said warp yarns (3, 4) in said textile machine or the like (100), and said threading configuration, in which said second guiding roller (9) is spaced from said main roller (6) in order to allow the threading of said warp yarns (3, 4) in said textile machine or the like (100); said second guiding roller (9) being freely rotatable about a second axis of rotation for guiding (9a).

3. The tensioning device (1) according to claim 2, characterized in that said eccentric levers (12) are configured and shaped, respectively, to interfere and engage with said second guiding roller (9) in the transition between said weaving configuration and said threading configuration in such a way as to totally clear the area in front of said main roller (6) from said second guiding roller (9).

4. The tensioning device (1) according to one or more of the preceding claims, characterized in that said supporting structure (2) comprises two lateral shoulders (2a, 2b) which are arranged laterally to said main roller and fist and second guiding rollers (6, 8, 9) and are configured to be rested directly on the ground in front of said textile machine or the like (100) at said inlet of said warp yarns (3, 4).

5. The tensioning device (1) according to one or more of the preceding claims, characterized in that it comprises: - two first toothed profiles (10), which are formed externally and laterally to said main roller (6) and are integral in rotation with said main roller (6) about said main axis of rotation (6a); - two second toothed profiles (11), which are formed externally and laterally to said first guiding roller (8) and are integral in rotation with said first guiding roller (8) about said first guiding rotation axis (6a); said first and second toothed profiles (10, 11) being configured for their mutual meshing in said weaving configuration.

6. The tensioning device (1) according to one or more of the preceding claims, characterized in that said eccentric levers (12) are integral in rotation with two respective sprockets (14), which are idle with respect to said main roller (6), about said eccentric axis of rotation (12a), and said movement means (13) comprise an actuation shaft (15) which is motorized and provided with two pinions (16) which mesh with said sprockets (14) for the rotation of said eccentric levers (12) about said eccentric axis of rotation (12a) and consequently for the transition of said first guiding roller (8) from said weaving configuration to said threading configuration and vice versa.

7. The tensioning device (1) according to one or more of the preceding claims, characterized in that said second guiding roller (9) is rotatably associated with said supporting structure (2) by means of two supporting elements (21) which are associable with said supporting structure (2) in a removable manner so as to allow the release of said second guiding roller (9) from said supporting structure (2) in the transition from said weaving configuration to said threading configuration and so as to allow the repositioning of said second guiding roller (9) on said supporting structure (2) in the transition from said threading configuration to said weaving configuration.

8. The tensioning device (1) according to one or more of the preceding claims, characterized in that said eccentric levers (12) each comprise an end portion (22) which is substantially cradle-shaped and is adapted to engage with and support said second guiding roller (9); each of said end portions (22) being provided with a fixing element (24) of a removable type, adapted to temporarily bind said second guiding roller (9) to said eccentric levers (12).

9. A textile machine (100), characterized in that it comprises a tensioning device (1) according to one or more of the preceding claims.

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