SEAT BELT RETRACTOR

Abstract

In a seat belt retractor (12) for a vehicle, comprising a frame (14) in which a belt reel (10) is supported which includes a reel body (26) as wed as a first flange (32) and a second flange (34), said flanges being provided at the axial ends (28, 30) of the reel body (26) and each being arranged in a seat (22) of the frame (14), wherein the first flange (32) is rotatable relative to the reel body (26) and wherein between the first flange (32) and the reel body (26) a force limiter is provided, and at the seat (22) locking teeth (24) are provided and at the first flange (32) a toothing corresponding to the locking teeth is provided, the second flange (34) is rotatable relative to the reel body (26) and at the second flange (34) and/or at the reel body (26) interacting stops (50, 54, 58) are provided for limiting rotation of the second flange (34) relative to the reel body (26). Furthermore, the second flange (34) Includes a peripheral wall (44) which encloses the axial end (30) of the reel body (26) facing the second flange (34) in the peripheral direction.

Claims

1-12 (canceled)

13. A seat belt retractor (12) for a vehicle, comprising a frame (14) in which a belt reel (10) is supported which includes a reel body (26) as well as a first flange (32) and a second flange (34), said flanges being provided at the axial ends (28, 30) of the reel body (26) and each being arranged in a seat (22) of the frame (14), wherein the first flange (32) is rotatable relative to the reel body (26) and wherein between the first flange (32) and the reel body (26) a force limiter is provided, and at the seat (22) locking teeth (24) are provided and at the first flange (32) a toothing corresponding to the locking teeth is provided, wherein the second flange (34) is rotatable relative to the reel body (28) and at the second flange (34) and/or at the reel body (26) interacting stops (50, 54, 58) are provided which limit the rotation of the second flange (34) relative to the reel body (26), and wherein the second flange (34) includes a peripheral wall (44) which encloses the axial end (30) of the reel body (26) facing the second flange (34) in the peripheral direction.

14. The seat belt retractor according to claim 13, wherein at the first flange (32) a toothing is provided and at the seat (22) of the first flange (32) corresponding locking teeth (24) are provided.

15. The seat belt retractor according to claim 13, wherein on the outside of the peripheral wall (44) a toothing (48) is provided and at the seat (22) of the second flange (34) corresponding locking teeth are provided.

16. The seat belt retractor according to claim 15, wherein the toothing (48) is formed by interruptions (46) of the peripheral wall (44).

17. The seat belt retractor according to claim 13, wherein the second flange (34) is formed by an especially reformed one-piece sheet metal part.

18. The seat belt retractor according to claim 13, wherein the stops (50, 54, 58) project from the second flange (34) and from the reel body (28) in the axial direction (L) in the opposite direction.

19. The seat belt retractor according to claim 13, wherein the stop (50) is formed on the second flange (34) by embossing.

20. The seat belt retractor according to claim 13, wherein the stop is formed at the reel body by a bolt (54) protruding from the reel body (26) in the axial direction (L).

21. The seat belt retractor according to claim 13, wherein the stop at the second flange (34) interacts with a blade (58).

22. The seat belt retractor according to claim 21, wherein the blade (58) abrades material from the reel body (26) and accordingly acts as an additional force limiter.

23. The seat belt retractor according to claim 13, wherein between the second flange (34) and the reel body (26) a shear pin having a predetermined breaking point is provided.

24. The seat belt retractor according to claim 13, wherein the force limiter is a torsion rod (36).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further advantages and features are found in the following description in connection with the enclosed drawings, wherein:

[0020] FIG. 1 shows an exploded view of a belt reel according to the invention,

[0021] FIG. 2 shows a sectional view across the belt reel of FIG. 1,

[0022] FIG. 3 shows an axial top view onto the belt reel of FIG. 2,

[0023] FIG. 4 shows a perspective view of a seat belt retractor comprising the belt reel of FIGS. 1 to 3,

[0024] FIG. 5 shows an axial top view onto the seat belt retractor of FIG. 4,

[0025] FIG. 6 shows a detailed view of the seat belt retractor of FIG. 4,

[0026] FIG. 7 shows a second embodiment of a belt reel according to the invention,

[0027] FIG. 8 shows a sectional view across the best reel of FIG. 7,

[0028] FIG. 9 shows an axial top view onto the belt reel of FIG. 8,

[0029] FIG. 10 shows a perspective view of a seat belt retractor comprising the belt reel of FIGS. 7 to 9, and

[0030] FIG. 11 shows a detailed view of the seat belt retractor of FIG. 10.

DESCRIPTION

[0031] In FIGS. 1 to 3 a belt reel 10 for a seat belt retractor 12 illustrated in FIGS. 4 to 6 is shown. The seat belt retractor 12 comprises a frame 14 including a base plate 16 which has an opening 18 for mounting the seat belt retractor 12 fixedly to the vehicle as well as two parallel opposite tabs 20 each of which includes a seat 22 for the belt reel 10. At the edge of the seats 22 locking teeth 24 are provided for blocking the belt reel 10, as will be explained hereinafter.

[0032] The belt reel 10 comprises a reel body 28 onto which webbing can be wound and which is rotatable about a longitudinal axis L. At the axial ends 28, 30 of the reel body 28 a first flange 32 and a second flange 34 are provided.

[0033] The first flange 32 is coupled to a force limiter, in this case a torsion rod 38, so as to be movable together with the reel body 26 to a limited extent. For this purpose, a first end 38 of the torsion rod 36 is connected to the first flange 32 in a rotationally fixed manner (cf. FIG. 2). The opposite second end 40 of the torsion rod is coupled to the reel body 26 in a rotationally fixed manner. By rotation about the longitudinal axis L a limited rotation of the reel body 26 against the first flange 32 is possible while at the same time the torsion rod 36 is deformed. With high load acting on the webbing by a tensile force thus limited rotation of the reel body 26 against the first flange 32 is possible against the resistance of the torsion rod 36.

[0034] The second flange 34 is made from a flat sheet metal part and includes a circular wall 42 arranged radially with respect to the longitudinal axis L as well as a peripheral wall 44 which is directly adjacent to the radial wall 42 and encloses the axial end 30 of the reel body 26 in the peripheral direction. The walls 42, 44 are formed integrally with each other. The second flange 34 is reformed into a pot-shaped configuration by plastic deformation of the sheet metal part.

[0035] As is evident especially from FIG. 1, the peripheral wall 44 has plural interruptions 46 arranged at regular intervals and jointly forming a toothing 48. Said toothing 48 can interact with the locking teeth 24 of the frame 14 so as to block rotation of the second flange 34 relative to the frame.

[0036] Furthermore, at the radial wall 42 of the second flange 34 a stop 50 projecting axially against the reel body 26 is provided which is produced by embossing the sheet metal part. At the same radial distance from the longitudinal axis L a recess 52 is provided on the reel body 26 in which recess a bolt forming a stop 54 is inserted in the axial direction.

[0037] In the assembled state of the belt reel 10 the bolt is located in the direction of rotation D ahead of the stop 50, with the stops 50, 54 overlapping in the axial direction.

[0038] When the belt reel 10 is blocked by the fact that the first and second flanges 32, 34 are blocked within the frame 14, with an increasing force at first force limitation takes place by deforming the torsion rod 36. “Force limitation” in this context means controlled unwinding of webbing from the belt reel 10 so as to limit the force acting in the seat belt and to enable controlled forward movement of the vehicle occupant.

[0039] During said forcing limiting operation the reel body 26 is twisted relative to the second flange 34, wherein the stop 54, i.e. the bolt, is moved in the direction of rotation D. Said rotation is stopped when the bolt contacts the stop 50 in the direction of rotation D. In this way, after force limitation the reel body 26 is blocked against the second flange 34 so that no further webbing extension is possible.

[0040] As is evident from FIG. 4, the reel body 26 protrudes into the second flange 34 in the axial direction L so far that the axial end 30 of the reel body 26 is located in the seat 22 of the frame 14. This facilitates direct support of the reel body 26 when the belt reel 10 and, resp., the reel body 26 are blocked, i.e. reliable load transmission in the radial direction from the reel body 26 via the second flange 34 to the frame 14.

[0041] Since, as is evident from FIG. 4, the interruptions 46 at the peripheral wall 44 are interconnected by a land 56, in this blocked state the second flange 34 cannot be moved relative to the reel body 26 in the axial direction L, as the locking teeth engage in the interruptions 46. Thus, the stop 50 is reliably excluded from slipping off the bolt 54.

[0042] The structure of the belt reel 10 according to the invention thus permits, on the one hand, reliable load transmission to the frame 14 of the seat belt retractor 12; on the other hand, the second flange 34 is reliably prevented from deforming or axially slipping off.

[0043] The second flange 34 is manufactured in one piece from an especially flat sheet metal part, for example by reforming. The stop 50 as well as the interruptions 46 may be introduced to the still flat sheet metal part, for example, prior to reforming, thus substantially facilitating manufacture. It is also possible, however, to introduce the stop 50 during the reforming process.

[0044] A second embodiment of a belt reel 10 according to the invention is shown in FIGS. 7 to 9. The basic structure of said belt reel 10 corresponds to the structure of the belt reel 10 as shown in FIGS. 1 to 3.

[0045] Instead of the bolt, in this case a blade 58 is used, however. The blade 58 can be radially twisted by the stop 50. The cutting edge provided at the blade 58 abrades material from the land 60 which is formed spirally at the reel. Thus, in addition to the torsion rod, further force limitation can be effectuated which moreover may also be progressive or declining.

[0046] In addition to the stops 50, it is possible that between the reel body 26 and the second flange 34 a shear pin is provided which admits rotation of the second flange 34 against the reel body 26 only when a defined force has been exceeded. In this way it is ensured that force limitation by the torsion rod 36 takes place only when a predetermined force level has been exceeded.

[0047] In the case of the embodiment shown in FIGS. 7 to 9 comprising a pin 58 which is shorn, the structure of the second flange 34 including a peripheral wall 44 according to the invention in addition offers the advantage that shorn parts of the pin 58 remain within the second flange 34 and cannot drop out of the latter.