SELF-LOCKING BELT RETRACTOR

Abstract

A self-locking belt retractor comprising a belt shaft which is rotatably mounted in a frame, wherein a safety belt can be wound up said belt shaft, a blocking device which blocks the belt shaft if a predetermined feed-out acceleration of the safety belt in the feed-out direction of the safety belt is exceeded, and comprising a control disc device mounted on the belt shaft, the control disc device comprising a control disc and an inert mass which is mounted on the control disc so as to be pivotable about a pivot axis.

Claims

1. A self-locking belt retractor having a frame, a belt shaft rotatably mounted in the frame, on which a safety belt can be wound, a blocking apparatus which blocks the belt shaft when a predetermined pull-out acceleration of the safety belt is exceeded in the pull-out direction of the safety belt, and a control disc device mounted on the belt shaft, wherein the control disc device comprises a control disc and an inertia mass which is pivotably mounted on the control disc about a pivot axis, wherein a pretensioning apparatus is provided, which pretensions the inertia mass parallel to the pivot axis in the direction of the control disc.

2. The belt retractor according to claim 1, wherein the pretensioning apparatus is fixed to the control disc as a separate component.

3. The belt retractor according to claim 1, wherein the pretensioning apparatus has a deflectable spring arm which extends parallel to the control disc.

4. The belt retractor according to claim 3, wherein the spring arm has a receptacle for a protrusion designed on the inertia mass to form the pivot axis.

5. The belt retractor according to claim 3, wherein the spring arm has a protrusion which engages in a receptacle in the inertia mass to form the pivot axis.

6. The belt retractor according to claim 3, wherein a deflectable end of the spring arm is surrounded at least in portions by a locking web.

7. The belt retractor according to claim 3, wherein the spring arm has a stop projecting in the direction of the control disc at a distance from its deflectable end.

8. The belt retractor according to claim 1, wherein at least one tapering protrusion is provided to form the pivot axis.

9. The belt retractor according to claim 8, wherein exactly two tapering protrusions are arranged on opposite sides of the inertia mass.

10. The belt retractor according to claim 8, wherein a receptacle for a tapering protrusion is designed as a cone-shaped trough.

Description

[0021] The invention and the technical environment are explained below by way of example with reference to the figures. The following are shown schematically:

[0022] FIG. 1a: shows a side view of a self-locking belt retractor with an inertia mass that is not swung out,

[0023] FIG. 1b: shows the belt retractor of FIG. 1a with the inertia mass swung out,

[0024] FIG. 2: shows a control disc device of the belt retractor of FIG. 1,

[0025] FIG. 3: shows an exploded view of the control disc device,

[0026] FIG. 4: shows a side view of an inertial mass of the control disc device of FIG. 2,

[0027] FIG. 5: shows a cross-sectional view through the control disc device of FIG. 2 without the inertia mass,

[0028] FIG. 6: shows a perspective view of a pretensioning apparatus of the control disc device of FIG. 2 and

[0029] FIG. 7: shows an exploded view of the self-locking belt retractor of FIG. 1.

[0030] The self-locking belt retractor shown in FIGS. 1a, 1b and 7 comprises a frame 12 in which a belt shaft 13 for winding up a safety belt not shown is rotatably mounted.

[0031] The self-locking belt retractor 11 also comprises a blocking apparatus 16, which can be used to block the safety belt from being pulled out from the belt shaft 13. For this purpose, the blocking apparatus 16 has a blocking pawl 17, which can be activated to block the rotary movement of the belt shaft 13 and, in the activated state, engages in an external toothing 18 on the frame 12 of the belt retractor 11.

[0032] To actuate the blocking pawl 17, the belt retractor 11 has a control disc device 1 comprising a control disc 2, an inertia mass 3, a spring 14 and a pretensioning apparatus 5, wherein the inertia mass 3 is pivotably layered on the control disc 2 and is acted upon by the spring 4 with a spring force.

[0033] In the assembled state, the control disc device 1 is covered by a cap 15 not shown in FIGS. 1a and 1b (see FIG. 7).

[0034] During the extension of the safety belt, the control disc device 1 initially rotates with the belt shaft 13. In this state, the inertia mass 3 has not yet swung out, as represented in FIG. 1a. As soon as a predetermined pull-out acceleration is exceeded during pull-out, the inertia mass 3 shown in FIGS. 1a and 1b swings out about a pivot axis 4 (see FIG. 1b). The inertia mass 3 engages with a toothing, which stops the control disc 2 relative to the belt shaft 13. During the subsequent relative movement of the belt shaft 13 with respect to the stopped control disc 2, the blocking pawl 16 is actuated by a guide in a control contour in the control disc 2, causing the blocking pawl 16 to engage with the external toothing 18 on the frame 12. This also blocks the rotary movement of the belt shaft 13 relative to the frame 12.

[0035] The function of a self-locking belt retractor described above is known per se from the prior art.

[0036] Firstly, it is now proposed that the control disc device 1 comprises a pretensioning apparatus 5. The one-piece pretensioning apparatus 5 is designed in such a manner that it can be fixed to the control disc 3 in a force-fit and form-fit manner by means of a snap connection (see particularly FIG. 5).

[0037] As can be seen particularly from the detailed view in FIG. 6, the pretensioning apparatus 5 comprises a deflectable spring arm 6, which has a receptacle 7.1 at its deflectable end. The deflectable end of the spring arm 6 is surrounded by a locking web 9. In addition, the spring arm 6 has a stop 10 projecting (downwards in FIG. 5) towards the control disc 2.

[0038] In the assembled state of the belt retractor 11, a protrusion 8.1 of the inertia mass 3, which determines the pivot axis 4, is arranged in the receptacle 7.1 of the spring arm 6.

[0039] The pretensioning apparatus 5 is dimensioned in such a manner that the spring arm 6 pretensions the inertia mass 3 via the protrusion 7.1 parallel to the pivot axis 4 in the direction of the control disc 2, such that any play that would otherwise be present is compensated for and the inertia mass 3 cannot perform any relative movement in the direction of the pivot axis 4 to the control disc 2 that generates rattling noises.

[0040] The locking web 9 and the stop 10 are arranged and designed in such a manner that the protrusion 8.1 of the inertia mass 3 is prevented from unintentionally coming out of the receptacle 7.1.

[0041] On the other hand, it is proposed that the inertia mass 3 has protrusions 8.1 and 8.2 on opposite sides to form the pivot axis 4, which are pointed (see FIG. 4).

[0042] In the assembled state, the protrusion 8.1 is arranged in the receptacle 7.1 designed on the spring arm 6 of the pretensioning apparatus 5, while the protrusion 8.2 is arranged in a receptacle 7.2 designed in the control disc (see FIGS. 3 and 5). The receptacles 7.1 and 7.2 are designed as cone-shaped recesses, such that the tapering protrusions 8.1 and 8.2 and the receptacles 7.1 and 7.2 each have only point-shaped contact between them.

LIST OF REFERENCE SIGNS

[0043] 1 control disc device [0044] 2 control disk [0045] 3 inertia mass [0046] 4 pivot axis [0047] 5 pretensioning apparatus [0048] 6 spring arm [0049] 7.1 receptacle [0050] 7.2 receptacle [0051] 8.1 protrusion [0052] 8.2 protrusion [0053] 9 locking web [0054] 10 stop [0055] 11 bolt retractor [0056] 12 frame [0057] 13 belt shaft [0058] 14 spring [0059] 15 cap [0060] 16 blocking apparatus [0061] 17 blocking pawl [0062] 18 external toothing