Abstract: A device comprising a shaft, a front ring connected to this shaft, an end ring connected to the shaft at a distance A from the front ring, and a loose mixing ring, which is freely rotatable and located between the front ring and the end ring. The mixing ring has a first region in which its inside diameter is large enough for it to be able to overlap with a region of smaller diameter of the front ring has an adjoining region in which the mixing ring has on its inner side at least two channels (4k) which run axially parallel, at an angle in relation to the axis of the shaft or helically thereto, and also an adjoining third region in which its inside diameter is large enough for it to be able to overlap with a region of smaller diameter of the end ring and the mixing ring is so long that, in its respective end positions, the other of the two rings respectively is partially overlapped by the mixing ring. The mixing ring channels are offset in relation to each other.

Abstract: A head arm mounting device for one or more scanning heads in recording/playback apparatus for disk records, especially flexible magnetic disks, includes a pivot shaft for the head arm, this shaft being held in a mount, with the aid of spring means, in a manner such that it has no axial play, and producing, in conjunction with the head arm loading spring, a head loading force which is constant and essentially independent of the head arm deflection. The mounting device consists essentially of a mount and a pivot shaft, either of which may be associated with a spring. A one-piece frame-shaped member with an integral spring constitutes an optimum mount. In an advantageous embodiment, means are provided for finely adjusting the force exerted by the head arm loading spring, and for compensating for tolerances in the spring force of the loading spring in the quantity production of disk drive apparatus.

Abstract: A head positioning device for a disk drive unit comprises a Y-shaped drive band for displacing the carriage bearing the head(s), each divergent arm portion of the Y forming the same angle with the central longitudinal axis of the band. In another embodiment, the two divergent arm portions are connected together by a crosspiece. Advantageously, the drive band is made of steel having a tensile strength of from 1200 to 2500 N/mm.sup.2, especially from 2000 to 2500 N/mm.sup.2. The novel positioning device can be used with advantage in any type of system for recording, reproducing and storing audio, video, data or control signals.

Abstract: A device for positioning objects which have a low mass, especially for positioning magnetic heads over preselected magnetic tracks on at least one magnetic disk, which can be coupled to a drive, in a memory processing unit, in which a carriage, which is capable of being moved toward and away from the axis of rotation of the magnetic disk, carries at least one magnetic head, this carriage being so mounted between guide elements that it can be displaced by a drive motor longitudinally with respect to the chassis of the unit, wherein the guide elements, in particular pairs of anti-friction bearings, engage either side of the carriage, at least one of the pairs of anti-friction bearings being gimbal-mounted in order to counteract any tilting moments which may act on the carriage. The device advantageously includes a band-type drive mechanism for displacing the carriage, comprising a rotatable cylindrical member around which the band means is wound and which may serve as an additional bearing element.