LAYING HEAD FOR A THREAD WINDING UNIT

Abstract

A depositing head for a plurality of rovings each coming from a bobbin and having a longitudinal axis, the depositing head including a plurality of line roller pairs for rolling the rovings from the bobbins, each roller pair being intended to be associated, in operation, with only a given single roving and including an upstream roller and a downstream roller relative to the direction of unwinding of the rovings, the rollers rotating independently of one another.

Claims

1-13. (canceled)

14. A head for laying a plurality of strands each originating from a bobbin and having a longitudinal axis, the laying head comprising a plurality of pairs of line rollers for rolling the strands from the bobbins, each pair of line rollers being intended to be associated in operation with only one given strand and comprising an upstream roller and a downstream roller with respect to the direction of unwinding of the strands, the line rollers being independent of each other in rotation.

15. The laying head according to claim 14, wherein each pair of line rollers is associated with a release roller, said release rollers being coaxial and rotatable independently of each other.

16. The laying head according to claim 14, wherein the axes of rotation of the rollers are perpendicular to the longitudinal axis.

17. The laying head according to claim 16, wherein the upstream roller and the downstream roller of a pair of line rollers are arranged staggered with respect to the upstream and downstream rollers of another pair of rollers in a plane perpendicular to the axes of rotation of the rollers and containing the longitudinal axis.

18. The laying head according to claim 14, wherein the upstream roller and the downstream roller of a pair of line rollers are arranged staggered with respect to the upstream and downstream rollers of another pair of rollers in a plane parallel to the axes of rotation of the rollers.

19. The laying head according to claim 14, wherein at least two upstream rollers of two pairs of rollers are arranged coaxially in rotation on the same upstream pivot.

20. The laying head according to claim 14, wherein at least two downstream rollers of two pairs of rollers are arranged coaxially in rotation on the same pivot.

21. The laying head according to claim 14, wherein each roller comprises an annular groove for receiving a strand, this annular groove having a concave curved bottom surface.

22. The laying head according to claim 14, wherein the axis of the downstream roller of each pair of rollers is located off the plane containing the axis of rotation of the upstream roller and the axis of rotation of the release roller.

23. The laying head according to claim 14, wherein the longitudinal axis of the laying head is positioned so that there is a plane such that all axes of rotation of the rollers are arranged on the same side of said plane.

24. The laying head according to claim 14, wherein a strand of a bobbin is associated with each pair of rollers, the reinforcing fibers, preferably made of carbon fiber, of each strand being impregnated with a curable matrix.

25. A device for laying a plurality of strands each originating from a bobbin, comprising a laying head according to claim 14, said laying head being movable in rotation around the longitudinal axis.

26. A unit for winding at least one strand from a bobbin, the unit comprising a device according to the preceding claim or a laying head according to claim 14 and a robot for moving an object intended to be entirely or partially covered by said at least one strand of the bobbin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Other features, details and advantages will appear upon reading the detailed description hereinafter, and upon analyzing the appended drawings, wherein:

[0046] FIG. 1, already described before, is a schematic perspective view of a thread winding unit according to the prior art;

[0047] FIG. 2 is a schematic perspective view of a laying head according to the present document;

[0048] FIG. 3 is a top view of a laying head according to the present document;

[0049] FIG. 4 is a side view of a laying head according to the present document;

[0050] FIG. 5 is a schematic sectional view of a roller intended to be used with a laying head according to the present document;

[0051] FIG. 6 is a schematic view of four downstream rollers of a laying head according to the present document.

DESCRIPTION OF THE EMBODIMENTS

[0052] Reference is now made to FIGS. 2 to 4 which illustrate a laying head 8 with a longitudinal axis L extending according to a first longitudinal direction D1 according to the present document and which comprises two lateral arms B1, B2 spaced apart from one another according to a second direction D2 perpendicular to the longitudinal direction D1. This second direction D2 is perpendicular to a third direction D3 also perpendicular to the first direction D1. The laying head could comprise one single lateral arm B1 or B2.

[0053] Pairs of upstream 10.sub.k and downstream 12.sub.k rollers are arranged between the lateral arms B.sub.1, B.sub.2 and are independent of each other in rotation, i.e. in pairs. In the example represented in the figures, the laying head comprises four upstream rollers 10.sub.1, 10.sub.2, 10.sub.3, 10.sub.4, and four downstream rollers 12.sub.1, 12.sub.2, 12.sub.3, 12.sub.4. Each of the upstream 10.sub.k and downstream 12.sub.k rollers comprises an axis of rotation extending according to the second direction D2, the axes of the rollers are therefore perpendicular to the longitudinal direction D1 and to the longitudinal axis L of the laying head 8. The upstream 10.sub.k and downstream 12.sub.k rollers are so-called line rollers since they achieve guidance along a line of a strand M.sub.k., this line is parallel to the longitudinal axis L. It would still be possible to qualify them as rollers guiding a strand. In the example represented in the figures, one could note the presence of four strands M.sub.1, M.sub.2, M.sub.3, M.sub.4 each associated with a pair of upstream 10.sub.k and downstream 12.sub.k rollers. It should be understood that the present disclosure covers all configurations where the number k of pairs of rollers [10.sub.k, 12.sub.k] is greater than or equal to 2. It should be obviously understood that the invention is more particularly interesting when the number of pairs of rollers is large and for example greater than or equal to four.

[0054] As shown in FIG. 3, each upstream roller is associated with a downstream roller so as to form a pair of line rollers guiding a given strand, the other strands being guided by distinct pairs of line roller pairs.

[0055] It should be understood that the terms upstream and downstream refer to rollers positioned with respect to each other upstream or downstream with respect to the direction of unwinding or laying of the strands M.sub.1, M.sub.2, M.sub.3, M.sub.4, i.e. with respect to the unwinding direction of the strand. In this case, the direction of unwinding of the strand M.sub.1, M.sub.2, M.sub.3, M.sub.4 is oriented from left to right along the first direction D1.

[0056] Each pair of upstream 10.sub.k and downstream 12.sub.k line rollers is associated with a release roller 14.sub.k. The release rollers are coaxial with the axis 15. They are herein mounted on the same pivot 19. In the example of the laying head 8 represented in the figures, there are four release rollers 10.sub.1, 10.sub.2, 10.sub.3, 10.sub.4. Each pair of upstream and downstream rollers comprises a face for supporting the strand M.sub.k which is symmetrical with respect to a plane P.sub.k containing the first longitudinal direction D1 and the third longitudinal direction D3. The release roller associated with the pair of line rollers 10.sub.k, 12.sub.k comprises a surface for supporting the strand M.sub.k which is also symmetrical with respect to the plane P.sub.k. It should be understood that the aforementioned support faces are annular faces and with a circular section but that the supports are not annular.

[0057] The support faces 17 of the upstream 10.sub.k and downstream 12.sub.k line rollers are formed at the bottom of an annular groove 19. These bearing faces 17 may have a section with a concave curved shape, although represented as being substantially planar. These bottom faces 17 of the annular groove 19 may have a variable radius of curvature, in particular with a radius of curvature which increases from the center of the annular groove outwards the annular groove 19. Each upstream 10k and downstream 12.sub.k line roller may comprise two ball bearings 21 to ensure a perfectly centered rotational movement.

[0058] In the arrangement of the present description, the k rollers are arranged successively along the direction D2. The rollers 10.sub.k where k is odd are carried by the same pivot 16 and the rollers 10k where k is even are carried by the same other pivot 18. The pivot 16 is arranged upstream of the pivot 18. The rollers 12k where k is odd are carried by the same pivot 20 and the rollers 12k where k is even are carried by the same other pivot 22. The pivot 20 is arranged upstream of the pivot 22. The pivot 18 is arranged upstream of the pivot 20. The pivots 16, 18, 20, 22 are arranged upstream of the pivot 19 of the release rollers 14.sub.k. The pivots 16, 18, 20, 22 extend according to the second direction D2 and therefore extend perpendicular to the longitudinal axis L. One could observe that the pivots 16, 18, 20, 22 are arranged staggered along a plane perpendicular to the axes 16.sub.1, 16.sub.2, 16.sub.3, 16.sub.4 of the pivots 16, 18, 20, 22 and containing the longitudinal axis L (FIG. 4). Similarly, one could observe a staggered arrangement of the upstream and downstream even line rollers with the upstream and downstream odd line rollers, in a plane parallel to the axes of the line rollers or axes of rotation of the rollers 10.sub.k, 12.sub.k.

[0059] The k upstream rollers may be arranged successively along a direction D2 perpendicular to the longitudinal direction L and so that the odd upstream rollers are carried by a first upstream pivot 16 and the even upstream rollers are carried by a second pivot 18 arranged downstream of the first pivot 16.

[0060] The k downstream rollers may be arranged successively along a direction D2 perpendicular to the longitudinal direction L and so that the odd downstream rollers are carried by a third upstream pivot 20 and the even downstream rollers are carried by a fourth pivot 22 arranged downstream of the third pivot 20. Moreover, the third pivot 20 may be arranged downstream of the second pivot 18.

[0061] In FIG. 4, one could observe that the axis 20.sub.1, 22.sub.1 of the downstream roller 12.sub.1, 12.sub.2, 12.sub.3, 12.sub.4 of each pair of rollers is located off the plane containing the axis of rotation of the associated upstream roller 10.sub.1, 10.sub.2, 10.sub.3, 10.sub.4 and the axis of rotation 15 of the release roller 14.sub.k. Moreover, one could observe that the portion 24 of a strand M.sub.k located between an upstream roller and a downstream roller forms with the portion 26 of a strand M.sub.k located between the downstream roller and the release roller an angle substantially equal to 90. This angle may be comprised between 70 and 110, preferably between 80 and 100.

[0062] In FIG. 3, one could observe that a strand M.sub.k is guided, in the unwinding direction, by an upstream line roller 10.sub.k, a downstream line roller 12.sub.k and a release roller 14.sub.k and along a line P.sub.k. In the practical case, one could observe the presence of 4 lines, P.sub.k, P.sub.2, P.sub.3, P.sub.4.

[0063] The upstream line rollers comprise a first series of upstream rollers 10.sub.k where k is odd and which are carried by the same pivot 16 and a second series of upstream rollers 10.sub.k where k is even and which are carried by the same pivot 18. The downstream line rollers comprise a first series of downstream rollers 12.sub.k where k is odd and which are carried by the same pivot 20 and a second series of downstream rollers 12.sub.k where k is even and which are carried by the same pivot 22. The pivots 16, 18, 20, 22 are distinct in pairs. According to the longitudinal direction L and along the unwinding direction, one could observe that the pivots are arranged from upstream to downstream so as to have the pivot 16 of the first series of upstream rollers 10.sub.k where k is odd, the pivot 18 of the second series of upstream rollers 10.sub.k where k is even, the pivot 20 of the first series of downstream rollers 12.sub.k where k is odd, then the pivot 22 of the second series of downstream rollers 12.sub.k where k is even. A strand M.sub.k cooperates with an upstream roller of a series of upstream rollers and a downstream roller of a series of downstream rollers. More particularly, a strand M.sub.k with k being an odd number cooperates with an upstream roller of the first series of upstream rollers and a downstream roller of a first series of downstream rollers and a strand M.sub.k with k being an even number cooperates with an upstream roller of the second series of upstream rollers and a downstream roller of a second series of downstream rollers. The arrangement of the rollers is such that the strands M.sub.k with k being an even number and the strands M.sub.k with k being an odd number are arranged alternately along the second direction D2.