Abstract: A force transmitting arrangement, useable as force amplifier of drive arrangements, transmits the moment of a reversible electric motor, acting as a servo motor or as a drive motor, over a friction core and a looped spring cooperating therewith to an output shaft. The looped spring has a pair of outwardly bent ends, which at the outer sides thereof drive, while taking up a tension force, an output entrainment member connected to the output shaft, whereas an input entrainment member connected with a manually operated drive, for instance the steering wheel of a motor vehicle, is located between the outwardly bent ends of the looped spring.

Abstract: An electromotor driven regulating arrangement, especially for regulating the speed of a motor vehicle, comprises an input shaft rotatable in one and in the opposite direction by a reversible electric motor, an output shaft adapted to be connected to a member for regulating the speed of the vehicle, and a coupling having two coupling members respectively connected with the input shaft and the output shaft for rotation therewith and a looped spring arranged between the coupling members by means of which the coupling members may be connected for simultaneous rotation in either direction. The arrangement comprises further a control member and electromagnet means cooperating therewith and acting on the spring for rendering the coupling active or inactive depending on whether the electromagnet is energized or deenergized.

Abstract: A servo arrangement, especially for brake force amplifiers for automotive vehicles, in which a servomotor provides an auxiliary moment which is transmitted by a coil spring coupling to a linkage. The coil spring has a hook-shaped rear end adapted to be engaged by a first entrainment member connected to a power take-off means of the arrangement so as to tighten the coil spring about the peripheral surface of a cylinder driven by the servomotor and the front end of the coil spring, at which the first coil of the spring is outwardly bent in form of a spiral, is adapted to be engaged by a second entrainment member connected to operator controlled force applying means to expand the coil spring so that the latter may slip on the peripheral surface of the cylinder.