Abstract: An apparatus for rotating a magnetic disc provided with a central hole and an entrainment opening comprises a hub member which is mounted on the shaft of an electric motor and which is provided with a flat surface on which the magnetic disc can be supported. The upper end of the shaft projects with play through the central hole in the disc. An entrainment peg which engages with the opening in the disc is fixed to one end of a movable arm which has the opposite end pivoted on the hub member. The entrainment peg is housed with play in a hole in the hub member and can move radially to center the disc with respect to the shaft of the motor, by virtue of a reaction force (F) imposed on the disc.

Abstract: This apparatus is used for recording and/or playing back a magnetic tape contained in a cassette provided with a hole for receiving a capstan roller and edge apertures for receiving a pressure roller adapted to press the tape against the capstan roller and a recording and/or reading head. The pressure roller is rotatably mounted between two parallel support levers which are pivotally mounted on the base about the same pivotal axis. A third lever pivoted about the said axis is coupled to the support levers by a lost motion coupling allowing limited relative pivotal mouvement between the support levers on the one hand and the third lever on the other hand. This apparatus further comprises a single actuation member which is movably mounted on the base to move the third lever to a position in which the pressure roller is moved into its position of engagement.