Patent Application
20080122281
The invention relates to an adjusting mechanism, especially a mechanism for adjusting the inclination of the backrest of a vehicle seat, comprising a bolt which is disposed on a first sub-assembly and a second sub-assembly which is mounted so as to be rotatable by means of said bolt and to which a force (F) may be applied in a radial direction relative to the axis of rotation.
A generic adjusting mechanism is known from the publication DE 1,984,5698A 1. The mechanism for adjusting the inclination of the backrest of a vehicle seat described in this document consists of a first fixing plate connected to the backrest and a second fixing plate disposed on the seat part, which are rotatably connected to one another. A circular-arc-shaped peripheral region of the second fixing plate is provided with a toothed portion with which a latching pawl, which is rotatably mounted on the first fixing plate, may be brought into engagement. As a result of this engagement, which may be released for the adjustment, the angular position between the backrest and seat part may be fixed. A locking cam, also rotatably disposed by means of a bolt on the first fixing plate, prevents undesirable unlocking of the. latching pawl. Both in normal use, but especially under overload.due to an accident, a force acts on the bolt in a radial direction relative to the axis of rotation of the locking cam. In this connection, a structural load limit is preset, up to which the clamping force of the locking cam is maintained and thus the backrest remains fixed in its set position.
The object of the invention is to improve the safety of a generic adjusting mechanism at low cost.
The object is achieved according to the invention in that, with a generic mechanism, the rotatability of the second sub-assembly relative to the first sub-assembly may be reduced with the aid of a positive connection between the bolt and the first sub-assembly and/or the second sub-assembly, which may be created using plastic deformation. The overload due to an accident, which essentially attempts to unlock the adjusting mechanism, thus simultaneously initiates (irreversible) means which counteract this unlocking.
The bolt may, in this case, be connected fixedly in terms of rotation to the first sub-assembly, and the positive connection being able to be created between the bolt and the second sub-assembly. Alternatively, it is conceivable to connect the bolt fixedly in terms of rotation to the second sub-assembly and to create the positive connection between the bolt and the first sub-assembly.
The positive connection is preferably able to be created by the bolt being rotatably mounted in a hole, which is at least partially toothed on its inner circumference, in the first or second sub-assembly. In this connection, the inner circumference of the hole advantageously has, at least in the region of the toothed portion, a greater hardness than the outer circumference of the bolt. When the overload occurs, the teeth dig into the bolt and prevent the rotation thereof relative to the hole. Under normal working load, however, the rotational movement is uninterrupted. Moreover, it is possible in principle, to unlock the adjusting mechanism again after the overload has subsided, for example to allow vehicle passengers to leave the vehicle by folding forward the backrest.
The toothed portion is preferably disposed in a segment of the inner circumference of the hole, the force application point of the force F under overload being disposed approximately centrally on the circular arc thereof. In this connection, the toothed segment extends on either side of the force application point, advantageously over an angle of less than 45°, preferably approximately 30°. In this angular range, the toothed portion deploys its greatest effect.
According to a preferred embodiment of the invention, the adjusting mechanism is a locking mechanism for adjusting the inclination of the backrest of a motor vehicle seat, the first sub-assembly being a first fixing plate connected to the backrest and the second sub-assembly being a locking cam, by means of which a latching pawl rotatably mounted on the first fixing plate may be held in engagement with the toothed portion of a second fixing plate which may be pivoted relative to the first fixing plate.
The figures show by way of example and schematically an embodiment of the invention, in which:
The adjusting mechanism 1 consists of a first fixing plate 2 for attaching to the backrest, not shown, as well as a second fixing plate 3 for fixing to the seat part of the vehicle seat, also not shown. The second fixing plate 3 is partially provided on its outer periphery with a toothed portion 4. A latching pawl 5, which, with a counter toothed portion 6, may be brought into positive engagement with the toothed portion 4, is rotatably disposed on the first fixing plate 2 (first sub-assembly). The locking in the locked position, as well as the unlocking, of the latching pawl 5 are carried out by a locking cam 7 (second sub-assembly) which is pivotably mounted on a rigid bolt 8 projecting from the first fixing plate 2. The locking cam 7 is driven by a toothed member 9. With regard to the function of such adjusting mechanisms, reference is made expressly to the aforementioned publication DE 1,984,5698 A1, and with regard to the configuration of the toothed member 9, reference is made to the, as yet unpublished, patent application DE 1,031,2136.6-16.
During normal use, especially however under overload due to an accident, a force F, which is diverted into the first fixing plate 2 via the bolt 8, is already applied to the locking cam 7, shown enlarged in
As is visible from
| Number | Date | Country | Kind |
|---|---|---|---|
| 102004048349.3 | Oct 2004 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP05/10191 | 9/21/2005 | WO | 00 | 3/30/2007 |
