Abstract: In a stopping device for a shaft, which acts in all three dimensions and is unaffected by large accelerations, a gear on the shaft of an engine is stopped by a locking pawl which engages the gear when the electromagnet is not excited. A magnetic field generated by the passage of current through a coil produces a torque which turns the rotating armature against the force of a spring in such a way that the locking pawl is moved radially outward around the gear and over a guide pin on the rotating armature which can be moved in a guide slot of the locking pawl, and thereby releases the gear and hence the shaft.