This application is a continuation of International Application PCT/DE2006/000080,which has an international filing date of Jan. 16, 2006; this International Application was not published in English, but was published in German as WO 2006/076898, and which claims priority to German Applications DE 10 2005 003 187.0, filed Jan. 19, 2005 and DE 10 2005 027 911.2, filed Jun. 10, 2005, and claims priority to U.S. provisional application 60/644,575, filed Jan. 19, 2005, all of which are incorporated herein by reference in their entireties.
The invention relates to a safety device for a motor vehicle seat and to a method for actuating such a safety device.
A safety device is assigned to a motor vehicle seat and has a seat surface which extends in the longitudinal direction of the seat and is intended to be occupied by a person sitting on the seat surface and is typically formed by an upholstered seat element. The safety device also comprises a securing element which is assigned to the seat surface and an adjustment device which is operatively connected to the securing element. The adjustment device serves to adjust the securing element from a reclining position into a securing position in the event of a crash, and to reset the securing element from the securing position into the reclining position at a later time.
In the securing position, the securing element acts on the seat surface without changing its position relative to the seat, in such a way that the seat surface and the securing element together prevent a person who is wearing a seat belt of the respective vehicle seat from dipping under the seat belt, specifically its lap belt, when said person is moved forward in the direction of travel due to a crash. This effect is also referred to as “submarining.”
The seat surface forms a component of the motor vehicle seat to which the safety device is assigned. However, at the same time it also forms a component of the safety device itself because, together with the securing element, it is intended to limit the forward movement of the pelvic area of a person sitting on the seat surface. For this purpose, the securing element is moved closer to the seat surface (of the upholstered seat element) by means of the adjustment device, in which case, under certain circumstances, a certain degree of deformation of the seat surface can also occur. However, in this context, the spatial position of the seat surface is not changed in its entirety (for example as a result of a pivoting of the seat surface).
A safety device is disclosed in published patent document WO 2004/007237 (incorporated by reference herein). In the event of a crash or when a pre-crash warning system is triggered, the seat surface of the motor vehicle seat is stiffened by the adjustment of the securing element in order to prevent a person located on the vehicle seat from slipping out under the seat belt. After the accident, the securing element can be reset again into its reclining position.