Belt Retractor With Two-Part Tensioning Drive Wheel

Abstract

A belt retractor having a belt shaft having a shaft body, a profile head and a torsion bar, wherein the torsion bar arranged in the shaft body is connected on one end to the shaft body and on a second end to the profile head, and the profile head can be securely attached to the vehicle, and having a belt pretensioner, wherein a pretensioner drive wheel of the belt pretensioner is directly connected in a rotationally fixed manner to the profile head of the belt shaft, and mass bodies can be engaged with the pretensioner drive wheel so as to transmit force to drive the belt shaft in winding direction. The pretensioner drive wheel (16) is configured by means of two parts, the profile head (1) of the belt shaft and a push-on ring (2) that is pushed onto the profile head (1) and is positively and non-positively connected thereto, wherein respectively mutually opposite dome-shaped partial receiving socket segments (3), which form together receiving sockets for the mass bodies, are formed on the profile head (1) and on the push-on ring (2).

Claims

1. A belt retractor having a belt shaft, a shaft body and a torsion bar comprising a profile head, wherein the torsion bar arranged in the shaft body is connected on one end to the shaft body and on a second end to the profile head, and the profile head can be securely fixed with respect to the vehicle, and having a belt pretensioner, wherein pretensioner drive wheel of the belt pretensioner is directly connected in a rotationally fixed manner to the profile head of the belt shaft, and mass bodies can be engaged with the pretensioner drive wheel so as to transmit force to drive the belt shaft in a seatbelt winding direction, the pretensioner drive wheel is configured of two parts, the profile head of the belt shaft and a push-on ring that is pushed onto the profile head and is positively and non-positively connected thereto, wherein respectively mutually opposite dome-shaped partial receiving socket segments, which which together form receiving sockets for the mass bodies, are formed on the profile head and on the push-on ring.

2. The belt retractor according to claim 1, further comprising the profile head of the belt shaft has an axially extending annular-shaped projection, in which the torsion bar is accommodated, and the push-on ring is fully inserted onto the annular-shaped projection, wherein at least one end area of the projection extending above the inserted push-on ring is plastically deformed for non-positive connection with the inserted push-on ring.

3. The belt retractor according to claim 1, further comprising an axially extending, annular-shaped push-on sleeve, whose one frontal surface makes contact with the profile head, is configured on the push-on ring.

4. The belt retractor according to claim 1, further comprising an annular-shaped slot is configured on the profile head, and an axially extending, annular-shaped push-on sleeve configured on the push-on ring is inserted therein.

5. The belt retractor according to claim 2, further comprising the push-on sleeve has a length which is at least as great as a diameter of the receiving sockets for the mass bodies configured by means of two dome-shaped partial receiving socket segments, and the push-on sleeve makes contact with the projection in the interior over the entire length.

6. The belt retractor according to claim 2, further comprising axially aligned grooves are configured radially outside on the projection for accommodating corresponding axially positioned springs on the inside of the push-on ring, and deformation elements are configured on the front face of the projection aligned with the grooves, which elements are plastically deformed to connect the profile head to the push-on ring and to the second end of the torsion bar.

7. The belt retractor according to claim 1, further comprising a bearing ring for the shaft body is configured as one piece on the push-on ring and positioned on a side facing the shaft body, wherein the shaft body and the two-part pretensioner drive wheel axially overlap each other in the area of the bearing ring.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0017] The invention as well as the technical environment will be described below with the aid of the figures, wherein it is emphasized that the figures depict a preferred embodiment of the invention, but that the latter is not limited thereto. The schematic figures show:

[0018] FIG. 1; is a perspective view of a profile head with a push-on ring pushed thereon,

[0019] FIG. 2; is a sectional view through the profile head with the push-on ring pushed thereon,

[0020] FIG. 3; is a perspective view of the profile head,

[0021] FIG. 4; is a sectional view through the profile head,

[0022] FIG. 5: is a perspective view of the push-on ring, and

[0023] FIG. 6; is a sectional view through the push-on ring.

DETAILED DESCRIPTION

[0024] FIGS. 1 through 4 depict, among other things, a profile head 1 of a belt retractor having a stud or post 14 for mounting the profile head 1 on a housing of the belt retractor (not shown). A blocking latch receiving element 15 is configured in the profile head 1, and a belt webbing-sensitive and/or vehicle-sensitive controllable blocking latch can be arranged therein (i.e. webbing sensitive or vehicle sensitive retractor locking). The profile head 1 has an annular-shaped projection 4, in whose interior a torsion bar can be inserted and secured by one end on a side opposite to the stud 14 and the blocking latch receiving element 15. On its outer periphery, the projection 4 has axially positioned grooves 11, to which deformation elements 13 connect flush with the grooves 11 on the front side in an end area 5 of the projection 4. An annular-shaped slot 7 that extends around the projection 4 is configured at an end of the projection 4 opposite to the end area 5.

[0025] A push-on ring 2, which is also represented in FIGS. 5 and 6, is inserted onto the projection 4 of the profile head 1. The push-on ring 2 forms an axially projecting annular-shaped push-on sleeve 6. The push-on sleeve 6 has a length 9. The push-on ring 2 has on its inner side axially positioned springs 12, which correspond to the grooves 11 on the profile head 1. The push-on ring 2 has a bearing ring 8 configured as one piece and located on a side opposite to the push-on sleeve 6.

[0026] For assembly, the push-on ring 2 is pushed onto the projection 4 of the profile head 1, wherein the springs 12 engage in the grooves 11. The push-on ring 2 is inserted thereby with the push-on sleeve 6 into the annular-shaped slot 7 until the front side of the push-on sleeve 6 comes in contact with the profile head 1. The dome-shaped semi spherical socket segments 3 on the profile head 1 and on the push-on ring 6 form together, respectively in pairs, receiving sockets with a diameter 10 for mass bodies of a belt pretensioner in the inserted state. A pretensioner drive wheel 16 is thus configured in two parts by the profile head 1 and the push-on ring 2.

[0027] The deformation elements 13 are deformed in the peripheral direction by an applied force in order to non-positively fix the push-on ring 2 on the projection 4. In particular, a torsion bar, which is not depicted, can be inserted into the inside diameter of the projection 4 having spline type features before the application of force, wherein the deformation elements 13 are exposed to and deformed by a radially inward force, in addition to being exposed to a force in the peripheral direction, so that the torsion bar is non-positively locked in the projection 4 and connected to the profile head 1. The length 9 of the push-on sleeve 6 is greater than the diameter 10 of the receiving elements for the mass bodies formed by the partial receiving elements 3 in order to ensure the most secure connection possible between the push-on ring 2 and the profile head 1, and to make available a large bearing surface between the push-on ring 2 and the profile head 1.

[0028] When it is mounted on a belt retractor, the bearing ring 8 configured on the push-on ring 2 overlaps on the radially outward positioned shaft body, which is radially supported by the bearing ring 8, at least when under load.

[0029] While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.