Unit for producing an assembly

Abstract

An apparatus for producing an assembly of filamentary elements that are wound together in a helix includes a twisting device, a preforming device, and an assembling device. The twisting device is structured to twist at least first and second filamentary elements individually, such that each filamentary element is twisted separately from another filamentary element, to produce at least first and second twisted filamentary elements. The preforming device, which is arranged downstream of the twisting device, is structured to preform each of the twisted filamentary elements individually into separate preformed helixes, to produce at least first and second preformed helixes. The assembling device, which is arranged downstream of the preforming device, is structured to assemble the preformed helixes into an assembly.

Claims

1. An apparatus for producing an assembly of filamentary elements wound together in a helix around a central core, the apparatus comprising: a twisting device structured to twist a plurality of filamentary elements individually, so that at least a first filamentary element is twisted separately from a second filamentary element, to produce a plurality of twisted filamentary elements that are separate from one another; a preforming device arranged downstream of the twisting device, the preforming device being structured to preform each of the twisted filamentary elements individually, so that at least a first twisted filamentary element is preformed separately from a second twisted filamentary element, to produce a plurality of preformed helixes that are separate from one another; an assembling device arranged downstream of the preforming device, the assembling device being structured to assemble together the preformed helixes around the central core, to produce the assembly of filamentary elements, in which the central core exhibits a non-zero twist; and a central core feeder, arranged upstream of the assembling device, that feeds the central core, which comprises a plurality of textile filamentary elements, to the assembling device, wherein where a diameter of each of the plurality of filamentary elements is d, and each of the plurality of preformed helixes has a helix angle , a helix pitch P, and a helix diameter D, the following conditions are satisfied: P=k1d, where k1=15 to 50, D=k2d, where k2=2 to 5, and is 10 to 25.

2. The apparatus according to claim 1, further comprising a filamentary elements feeder arranged upstream of the twisting device, the feeder being structured to feed the filamentary elements to the twisting device.

3. The apparatus according to claim 1, wherein the plurality of filamentary elements comprises six filamentary elements, each having a diameter of 0.15 to 0.35 mm, and wherein the assembly of filamentary elements has a structural elongation of greater than or equal to 3.0% as measured in accordance with ASTM A931-08.

4. The apparatus according to claim 1, wherein each of the plurality of filamentary elements has a circular cross-section, and wherein the assembly of filamentary elements has a structural elongation of greater than or equal to 5.0% as measured in accordance with ASTM A931-08.

5. The apparatus according to claim 1, wherein the assembling device includes a distributor and an assembly guide.

6. The apparatus according to claim 5, further comprising a filamentary elements feeder arranged upstream of the twisting device, the feeder being structured to feed the filamentary elements to the twisting device.

7. The apparatus according to claim 5, further comprising a rotation maintaining device arranged downstream of the assembly guide, the rotation maintaining device being structured to maintain a rotation of the assembly of filamentary elements.

8. The apparatus according to claim 7, wherein the assembling device includes a bow positioned downstream of the assembly guide.

9. The apparatus according to claim 8, wherein the assembling device includes a pod arranged downstream of the assembly guide, the pod including a storage device structured to store the assembly of filamentary elements.

10. The apparatus according to claim 9, wherein the pod includes a balancer structured to balance the assembly of filamentary elements, the balancer comprising a twister.

11. The apparatus according to claim 7, wherein the assembling device includes a pod arranged downstream of the assembly guide, the pod including a storage device structured to store the assembly of filamentary elements.

12. The apparatus according to claim 11, wherein the pod includes a balancer structured to balance the assembly of filamentary elements, the balancer comprising a twister.

13. The apparatus according to claim 7, further comprising a filamentary elements feeder arranged upstream of the twisting device, the feeder being structured to feed the filamentary elements to the twisting device.

14. The apparatus according to claim 5, wherein the assembling device includes a bow positioned downstream of the assembly guide.

15. The apparatus according to claim 14, wherein the assembling device includes a pod arranged downstream of the assembly guide, the pod including a storage device structured to store the assembly of filamentary elements.

16. The apparatus according to claim 15, wherein the pod includes a balancer structured to balance the assembly of filamentary elements, the balancer comprising a twister.

17. The apparatus according to claim 14, further comprising a filamentary elements feeder arranged upstream of the twisting device, the feeder being structured to feed the filamentary elements to the twisting device.

18. The apparatus according to claim 5, wherein the assembling device includes a pod arranged downstream of the assembly guide, the pod including a storage device structured to store the assembly of filamentary elements.

19. The apparatus according to claim 18, wherein the pod includes a balancer structured to balance the assembly of filamentary elements, the balancer comprising a twister.

20. The apparatus according to claim 19, further comprising a filamentary elements feeder arranged upstream of the twisting device, the feeder being structured to feed the filamentary elements to the twisting device.

21. The apparatus according to claim 18, further comprising a filamentary elements feeder arranged upstream of the twisting device, the feeder being structured to feed the filamentary elements to the twisting device.

22. An apparatus for producing an assembly of filamentary elements wound together in a helix around a central core, the apparatus comprising: a twisting device structured to twist a plurality of filamentary elements individually, so that at least a first filamentary element is twisted separately from a second filamentary element, to produce a plurality of twisted filamentary elements that are separate from one another; a preforming device arranged downstream of the twisting device, the preforming device being structured to preform each of the twisted filamentary elements individually, so that at least a first twisted filamentary element is preformed separately from a second twisted filamentary element, to produce a plurality of preformed helixes that are separate from one another; an assembling device arranged downstream of the preforming device, the assembling device being structured to assemble together the preformed helixes around the central core, to produce the assembly of filamentary elements; and a central core feeder, arranged upstream of the assembling device, that feeds the central core, which comprises a plurality of textile filamentary elements, to the assembling device, wherein where a diameter of each of the plurality of filamentary elements is d, and each of the plurality of preformed helixes has a helix angle , a helix pitch P, and a helix diameter D, the following conditions are satisfied: P=k1d, where k1=15 to 50, D=k2d, where k2=2 to 5, and is 10 to 25, wherein the assembling device includes a pod arranged downstream of the assembly guide, the pod including a storage device structured to store the assembly of filamentary elements, wherein the pod includes a balancer structured to balance the assembly of filamentary elements, the balancer comprising a twister, and wherein the pod and the central core feeder rotate synchronously around an axis, extending from the central core feeder to the assembling device, along which the central core feeder feeds the central core.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood from reading the following description, which is given solely by way of non-limiting example and with reference to the drawings in which:

(2) FIG. 1 is a diagram of a unit according to a first embodiment and making it possible to implement a method according to a first embodiment and to produce the assembly of FIG. 2;

(3) FIG. 2 is a view in section perpendicular to the axis of the assembly (presumed to be rectilinear and at rest) of an assembly produced by means of the unit of FIG. 1;

(4) FIG. 3 is a view of a thread of the assembly of FIG. 2, projected onto a plane parallel to the axis of the assembly;

(5) FIG. 4 is a diagram of a unit according to a second embodiment of the invention and making it possible to implement a method according to a second embodiment and to produce the assembly of FIG. 5;

(6) FIG. 5 is a view in section perpendicular to the axis of the assembly (presumed to be rectilinear and at rest) of an assembly produced by means of the unit of FIG. 4;

(7) FIG. 6 is a diagram of a unit according to a third embodiment of the invention and making it possible to implement a method according to a third embodiment and to produce the assembly of FIG. 7;

(8) FIG. 7 is a view in section perpendicular to the axis of the assembly (presumed to be rectilinear and at rest) of an assembly according to a third embodiment produced by means of the unit of FIG. 6.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(9) FIG. 1 depicts a unit for producing an assembly A of filamentary elements wound together in a helix. This unit, according to the invention, is denoted by the overall reference 10.

(10) The unit 10 comprises, from upstream to downstream when considering the direction in which the filamentary elements travel:

(11) feed means 12 for feeding M filamentary elements 14,

(12) twisting means 16 for individually twisting each filamentary element 14 and arranged in such a way as to twist each filamentary element 14 separately from one another

(13) preforming means 18 for individually preforming each filamentary element 14 and arranged downstream of the twisting means and in such a way as to preform each twisted filamentary element 14 separately from one another,

(14) means 20 of assembling the filamentary elements 14 together into a helix to form the assembly A and arranged downstream of the preforming means and in such a way as to form the assembly of filamentary elements,

(15) means 24 of maintaining the rotation of the assembly A about its axis,

(16) means 26 of balancing the assembly A, and

(17) means 28 of storing the assembly A.

(18) The unit 10 also comprises means of guiding, paying out, and applying tension to the filamentary elements and the assembly as conventionally used by those skilled in the art, for example pulleys and capstans.

(19) The feed means 12 comprise a spool 30 holding each filamentary element. For the sake of clarity of the figures, these depict only two filamentary elements 14 and therefore only the corresponding means.

(20) The means 16 of individually twisting each filamentary element 14 comprise a twisting device 32, also more commonly known to those skilled in the art as a twister, for example a two-pulley twister.

(21) The means 18 of individually preforming each filamentary element 14 comprise, for example, a roller-type preforming device 34 such as described in U.S. Pat. No. 5,533,327A or U.S. Pat. No. 4,566,261A.

(22) The means of assembly 20 comprise a distributor 36 and, downstream of that, an assembly guide 38.

(23) The means 24 of maintaining the rotation are arranged downstream of the assembly guide 38 and comprise a twister 40, for example a two-pulley twister making it possible to maintain the rotation of the assembly A respectively about the main direction of the assembly A.

(24) Downstream of the means 24 of maintaining the rotation and of the assembly guide 38, the means of assembly 20 comprise a bow 42 and a pod 44 for carrying the balancing means 26 and the storage means 28. The bow 42 and the pod 44 are mounted with the ability to rotate so as to dictate the pitch of the assembly A.

(25) The balancing means 26 comprise a twister 46, for example a four-pulley twister.

(26) The storage means 28 here comprise a spool 48 for storing the assembly A.

(27) FIGS. 2 and 3 depict the assembly A according to the first embodiment of the invention, produced by means of the unit of FIG. 1.

(28) The assembly A comprises, here consists of, a single layer 500 formed of the M filamentary elements of the assembly. The M filamentary elements are wound together in a helix. The layer 500 comprises between 2 and 9 filamentary elements 14. In this instance, the layer 500 comprises, here consists of, M filamentary elements 14 (M=6). The assembly A of FIG. 2 has no central core.

(29) Each filamentary element 14 comprises, here consists of, a single metallic elementary monofilament of circular cross section, in this instance made of carbon steel, having a diameter ranging from 0.05 mm to 0.50 mm, preferably ranging from 0.10 mm to 0.40 mm, and more preferably from 0.15 mm to 0.35 mm, and in this instance equal to 0.26 mm.

(30) The assembly A has a structural elongation greater than or equal to 2.0% measured in accordance with the standard ASTM A931-08. Advantageously, it has a structural elongation greater than or equal to 3.0%, preferably 4.0%, and more preferably 5.0%, measured in accordance with standard ASTM A931-08.

(31) Each thread 14 is preformed using the individual-preforming means 18. Each thread 14 follows a path in the form of a three-dimensional helix characterized by a helix angle , a helix pitch P and a helix diameter D.

(32) As illustrated in FIG. 3, the helix angle is equal, in a plane of projection of the helix through which the longitudinal axis thereof passes, to the angle measured between the projection of the longitudinal axis onto the plane of projection and the tangent to the projection of the helix at the point of intersection of the projection of the helix and of the projection of the longitudinal axis. The helix angle of each filamentary element 14 is comprised between 10 and 25.

(33) As illustrated in FIGS. 2 and 3, the helix diameter D is equal to the diameter of the circle described by the neutral axis F of each filamentary element 14. The helix diameter D can also be determined as being equal to the distance separating the centers of two filamentary elements that are diametrically opposed within the assembly A. The diameter D of the helix of each filamentary element 14 is such that D=k2.Math.d in which d is the diameter of each filamentary element 14, with k2 ranging from 2 to 5.

(34) As illustrated in FIGS. 2 and 3, the helix pitch P is equal to the distance, along the axis of the filamentary element, that is covered by a point on the neutral axis F of the filamentary element after it has made one complete turn of the circle described by the neutral axis F. The helix pitch P of at least each first and second filamentary element 14 is such that P=k1.Math.d in which d is the diameter of each filamentary element 14, with k1 ranging from 15 to 50.

(35) The assembly A is notably used in a tire and more preferably in the protective or hooping plies of tires such as described hereinabove.

(36) A method of producing the assembly A according to a first embodiment, using the unit 10, will now be described.

(37) First of all, the filamentary elements 14 are paid out individually from the feed means 12, in this instance the spools 30.

(38) Next, the method comprises a step of individually twisting each filamentary element 14. Thus, each filamentary element 14 is twisted individually and separately with respect to the others. The step of individually twisting the filamentary elements 14 is performed using the twisters 32. During this twisting step, each filamentary element 14 is made to experience twisting about its own axis, then each filamentary element 14 is twist-balanced. After the individual-twisting step, each filamentary element 14 is therefore twisted and twist-balanced.

(39) Next, the method comprises a step of individually preforming each previously-twisted filamentary element 14 into a helix. Thus, each previously-twisted filamentary element 14 is preformed individually and separately with respect to the others. The step of individually preforming the filamentary elements 14 is performed using the preformers 34.

(40) Next, the method comprises a step of assembling the twisted and preformed filamentary elements 14 with one another to form the assembly A of filamentary elements 14. The assembly step is performed using the distributor 36, the assembly guide 38, but also using means arranged downstream of the assembly guide 38, which are the bow 42 and the pod 44.

(41) Next, the method comprises a step of maintaining the rotation of the assembly A about its direction of travel. This step of maintaining the rotation is achieved by virtue of the twister 40.

(42) The method then also comprises a step of balancing the assembly A. This balancing step is performed downstream of the step of assembly using the twister 46.

(43) Finally, the assembly A is stored in the storage spool 48.

(44) FIGS. 4 and 5 illustrate a unit according to the invention and an assembly A both in accordance with a second embodiment. Elements analogous with those depicted in FIGS. 1 to 3 are denoted by identical references.

(45) Unlike in the first embodiment, the unit of FIG. 4 comprises, in addition to the means 12 of storing the filamentary elements 14, means 50 for feeding in a central core 15.

(46) Thus, as illustrated in FIG. 5, the assembly A comprises here consists of, a layer of M filamentary elements wound together in a helix around the central core 15 comprising N textile filamentary element(s) 17. The assembly A here is such that M=6 and N=1. As an alternative it is possible to conceive of N>1, for example N=2 or 3.

(47) Each textile filamentary element 17 here comprises several multifilament strands, each one referred to as an overtwist, each one comprising several elementary monofilaments and assembled together in a helix to form a plied yarn. The elementary monofilaments are textile, in this instance made of PET.

(48) Unlike in the method according to the first embodiment, the assembly step is a step of assembling the filamentary elements 14 and the central core 15. The assembly step is performed in such a way that the central core 15 exhibits a substantially non-zero twist. This twist is substantially equal to the twist imposed by the bow 42, the feed means 50 being stationary with respect to the assembly guide 38.

(49) FIGS. 6 and 7 illustrate a unit according to the invention and an assembly A both in accordance with a third embodiment. Elements analogous with those depicted in the preceding figures are denoted by identical references.

(50) Unlike in the second embodiment, the unit of FIG. 6 comprises, in addition to the means 50 for feeding the central core 15, means 52 of rotating the means 50. In this particular instance, these rotation means comprise a pod 54.

(51) Thus, as illustrated in FIG. 7, the assembly A comprises, here consists of, a layer of M filamentary elements wound together in a helix around the central core 15 comprising N metallic filamentary element(s) 17. The assembly A here is such that M=6 and N=1. As an alternative it is possible to conceive of N>1, for example N=2 or 3.

(52) Each metallic and filamentary element 17 here is a metallic elementary monofilament, for example a steel thread with a diameter of between 0.05 mm and 0.50 mm, in this instance equal to 0.20 mm.

(53) Unlike in the method according to the second embodiment, the assembly step is performed in such a way that the central core 15 exhibits substantially zero twist. This substantially zero twist is obtained by synchronizing the rotation of the bow 42 with the rotation of the feed means 50.

(54) The invention is not limited to the embodiments described above.

(55) Indeed, it is possible to envisage exploiting the invention with filamentary elements each comprising several metallic elementary monofilaments. Each filamentary element is then made up of a strand comprising the metallic elementary monofilaments. Once assembled, the filamentary elements or strands form a multi-strand rope.