Abstract: An acceleration sensor for safety systems such as seat belt systems in motor vehicles, particularly so-called buckle-connected tighteners, comprises a sensor mass which is generally held in a position of rest but is capable of displacement in response to a predetermined critical acceleration to activate the safety system. In one embodiment, an inertial force sensor consists of a sensor lever pivoted to a part fixed in the vehicle, said sensor lever carries at its upwardly protruding free end an inertial mass, preferably in the form of an enlarged head, the sensor lever being held by a spring which urges said sensor lever toward its vertical stand-by position, and being connected by levers and/or links to a release mechanism for releasing a spring-loaded tie rod or the like or a blocking device.

Abstract: In a device for coupling and locking a bracket, which is provided with a buckle of a seat belt, in case of danger to a retaining member, which is fixed in a vehicle, the bracket, or a housing part or the like which is connected to the bracket, is connected to a movable coupling member, which in a guide of a seat frame plate or the like is guided in such a manner or by a linkage is so connected to said seat frame plate or the like that a tension exerted on the buckle will cause the latter to be coupled to the retaining member, which is fixedly mounted in the vehicle.

Abstract: A belt tightener for seat belts in vehicles comprises a device for moving the belt buckle in a belt-tightening sense and for locking the belt buckle at the end of the tightening movement, which device is activated by a so-called vehicle-sensitive system in response to an acceleration or deceleration in excess of predetermined critical values.