The invention relates to a self-locking safety belt reeling device with a vehicle sensitive and/or belt-sensitive controlled locking device and with a tightening device acting on the belt reeling shaft, comprised of a drive disc driven in rotation by a drive device, wherein the drive disc, upon actuation of the tightening device, is coupled by a tightening coupling to the belt reeling shaft, whereby a force limiting device comprising a torsion bar is provided that, on the one hand, is connected to the rotatable belt reeling shaft and, on the other hand, to a stationary abutment. Further provided is a pawl coupling that is actuated by the tightening device and comprises one or more force limiting pawls for switching on and off the force limiting device as a function of the functional states of the belt reeling device and/or of the tightening device.
A safety belt reeling device combined with a tightening device and a force limiting device, which can be switched on or off according to functional states, is known in different constructive embodiments especially from German Patent Application 43 31 027 and also from European Patent Application 0 627 345. In all of these embodiments the switching on or off of the force limiting device is achieved by a pawl coupling that is controlled by centrifugal force whereby the rotation of the belt reeling shaft caused by the tightening device or by forward movement of the buckled-in person when restrained results in a rotational acceleration and the deflection of the respectively arranged force limiting pawls as a component of the pawl coupling. Since between the functional state of tightening, on the one hand, and the functional state of restraining, on the other hand, a rotational reversal of the belt reeling shaft and thus a forced short term standstill of the belt reeling shaft results, with the known centrifugally controlled pawl couplings the disadvantage is observed that in certain functional positions the force limiting pawls will not remain in the deflected position but upon standstill, due to the loss of centrifugal force, respectively, upon impact, will return into their initial positions so that the directed switching of the force limiting device will not occur. The invention therefor has the object to eliminate this disadvantage for a self-locking safety belt reeling device with the aforementioned features and to provide for a safe control of the force limiting pawls for realizing the desired switched position.
USPTO Backgrounds
USPTO Backgrounds