Abstract: A device for damping an oscillatory system is described. The device comprises a first connection member connectable to part of a spring and a second connection member connectable to a surface on which the spring is mounted. One end of a first bearing member is rotatably mounted in the first connection member and the other end is fixed in a mounting block. One end of a second bearing member is rotatably mounted in the block to extend perpendicularly of the first bearing member. The other end of the second bearing member is fixed in part of a planar component which is pivotally connected by a flexible joint to a second planar component. The device is symmetrical about the pivot line so that a third bearing member and a fourth bearing member corresponding to the second and first bearing member, respectively, are provided between the second planar component and the second connection member.

Abstract: Electrical equipment for controlling an electric motor for the horizontal movement of the pickup member of a disc-record gramophone towards and away from the center of the gramophone turntable comprises position-selector means which, when set to any one of a number of predetermined positions of the pickup member, start the motor and emit a normally constant speed-reference signal controlling the motor speed and, upon receipt of a position-identifying signal from the selected position, cause the motor to be de-energised, thus terminating the motor-driven movement of the pick-up member, individual position-detector means, each so constructed as to perform the dual function of emitting such position-identifying signal and of varying the normally constant reference signal in accordance with the residual distance of the pick-up member from the accurate location of the selected position, thereby varying the motor speed so that the position-detector means work, in conjunction with the motor, as an approach servo.

Abstract: An anti-skating and/or arm-moving device for a disc-record player comprises two permanent-magnet plates carried by the pickup-arm support and each extending over a sector of a circle round the same, the plates being magnetized, each across its thickness, with opposite polarities to produce each a magnetic flux at right angles to the direction of plate movement, and a coil fixed to the player structure in which two conductor elements extend across the flux of each magnet plate respectively, transversely to the direction of magnet movement, and carry the coil current in opposite directions.Current cut-off means are preferably provided for cutting off the anti-bias current in the winding when, particularly during a manual cueing operation, the pickup stylus is lifted from the record surface, and conversely preventing the application of arm-moving current when the stylus rests on a record.