Abstract: A lever (14) is fixed to a shaft (15) which can be connected to a rotation shaft (19) of a device such as a potentiometer. The shaft (15) is journaled in a pair of support plates (10, 11) which are rigidly connected to one another, and brake discs (23) having brake linings (22) are arranged between the lever (14) and the support plates (10, 11). Cup springs (24) provide a spring force acting transversely to the operational direction of the lever (14), so that frictional forces provided by the brake linings (22) assure a smooth and jolt free operation of the lever (14).

Abstract: A rotary scanning device is proposed with a rotary body carrying at its periphery a plurality of magnetic recording heads which can be driven by associated recording amplifiers. The individual recording amplifiers are accommodated on circuit boards which are mounted in a paddle-wheel configuration between two annular conductor boards by means of holders. The two annular conductor boards are rotationally locked to the rotary body. The circuit boards have a forward inclination in the direction of rotation of the rotary body.