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.

Abstract: A drive and locking system enables a rotor (2) to be turned between two end portions which are rotationally displaced in relation to one another through a present angle, and allows the rotor to be locked in an end position. Corresponding to the end positions are end stops (1a, 1b) against which the drive urges the rotor (2). In this position movable levers (12), which are disposed between two parts and fixed to one of them, can be released. The levers (12) are provided with teeth (11) which then engage in recesses in the rotor (2). The still-effective drive moment of the drive system then entrains the part (13), to which the levers (12) are not fixed, in a direction opposite to the rotational direction of the rotor. The levers (12) are then guided from the position in which they link both parts by passing over sloping surfaces, and the levers (12) are then brought into a locking position of the rotor (2) and of the part (14) which is provided with the levers (12).