Abstract: A magnetic disc in a cartridge is ventilated to keep a data containing surface portion thereof substantially free of particulate materials. A recirculating gas path includes apertured conduits for supplying gas jets completely across the portion as the disc is rotating in an enclosure. An orifice removes gas from the enclosure. A fan circulates the gas removed from the enclosure through the orifice and supplies the circulated gas back to the apertured conduits. Magnetic heads are positioned relative to the orifice and an inlet for the gas jets such that the gas has laminar flow as the gas passes the magnetic heads so the gas flow does not affect the position of the heads relative to the disc portion. The recirculating path includes filters for removing particulate materials from the recirculating gas.

Abstract: A magnetic disc cartridge is adapted to be selectively inserted into a receptacle of a magnetic disc memory unit having a head for transducing magnetic data of a disc of the cartridge. The memory unit has a disc drive shaft having: (a) a rotation axis, (b) a reference plane at right angles to the rotation axis, and (c) a flange coaxial with the rotation axis. The cartridge includes a hub for coupling the drive shaft to the disc so the disc is turned by the drive shaft while the cartridge is in the receptacle. The hub and drive shaft axes are substantially coincident and invariably located at the same position when the cartridge is in the receptacle, a result achieved by a structure for precentering the cartridge with respect to the rotation axis and an elastically deformable structure mounted on the hub. The deformable structure has a first surface generally at right angles to the hub axis of rotation and a second surface extending coaxially with an axis of the hub.

Abstract: An actuator for loading the main body of a platform having at least one read/write transducer associated with a data medium comprising at least one rigid movable arm (4), a flexible spring plate (10) attached to the rigid arm at one of its ends and supporting the platform (12) at its other end, the flexible plate (10) generating a force for pressing the main body against the data medium (14). The actuator is characterized in that flexible plates (10) are arranged in pairs, and means are provided for acting simultaneously upon the ends of two flexible plates (10) in order to bring them closer together. The means for acting simultaneously on the ends of two flexible plates are formed by two inclined cam profiles which act on a edge of a hole or slot provided in and along the central axis of each flexible plate and by means for shifting these cam profiles in relation to the edges of the flexible plates.