Abstract: A magnetic-tape apparatus has a magnetic-head unit with a magnetic head having a head face for guiding a magnetic tape. The magnetic head has transducing gaps for writing and/or reading information onto/from the magnetic tape. The magnetic-head unit further comprises two height limiters having tape-guide surfaces for guiding an edge of the magnetic tape. A tangent line, which is tangent to both tape-guide surfaces, extends perpendicularly to an imaginary line in the head face and passing through the transducing gaps. If an edge of the magnetic tape is in contact with the two height limiters, the position of the magnetic tape relative to the magnetic head is always the same, so that no azimuth errors can arise. In order to bring this edge of the magnetic tape into contact with the height limiters, the magnetic-head unit is mounted so as to be pivotable about an axis perpendicular to a tangent plane to the head face at the location of the transducing gaps.

Abstract: A transmission with variable mechanical prestress including a pinion driven by an electric motor, a driven gearwheel with its bearings in a housing, and an electromagnetic actuator for applying a prestress force which is controllable in dependence on an instantaneous load to be handled by the transmission. The electric motor with the pinion is supported so that it can be tilted relative to the housing. Owing to a tilting movement of the electric motor caused by the actuator, the pinion is pressed against the gearwheel with a certain prestress force in a radial direction. The transmission is free from play, while the virtual play arising from friction and hysteresis is strongly reduced, and the positioning accuracy is enhanced as a result.