Patent ID: 7725909

Claim:
Apparatus for centering an information medium ( 101 ) on a turntable, the apparatus comprising: a disc setting surface ( 3 ) for receiving the information medium ( 101 ) having a peripheral friction sheet ( 19 ) thereon; a stationary fitting member ( 4 ) in the form of a stationary metal yoke, for receiving the information medium ( 101 ) via a substantially central aperture ( 102 ) thereof, the stationary fitting member ( 4 ) including a ring magnet ( 46 ) on an upper surface and an angular groove ( 44 ) within which is provided a movable metal yoke ( 40 ) and; a plurality of inwardly directed and equally spaced, resiliently deformable members ( 12 ) extending from the disc setting surface ( 3 ) at a location adjacent the inner rim of said substantially central aperture ( 102 ) of said information medium, when the information medium ( 101 ) is loaded on said turntable; and a movable locking member ( 40 ) provided on the movable metal yoke at least a portion of which is formed of a ferrous material, the movable locking member ( 40 ) being cooperatively arranged relative to said plurality of resiliently deformable members ( 12 ); the movable locking member ( 40 ) including a sliding cam ( 40 a ), formed thereon, or integrally therewith, and is cooperatively arranged relative to the one or more resiliently deformable members ( 12 ), wherein said movable locking member ( 40 ) is arranged and configured to move, in a generally vertical direction, between a first position in which it exerts little or no pressure on said one or more resiliently deformable members ( 12 ) and a second position in which a generally radial force is exerted thereby on said one or more resiliently deformable members ( 12 ) such that said one or more resiliently deformable members ( 12 ) exert a corresponding centering force on said inner rim of said substantially central aperture ( 102 ) of said information medium ( 101 ), and a clamping member ( 15 ) having an annular circumferential edge ( 23 ) for pressing down on the information medium ( 101 ) to cause the information medium ( 101 ) to abut the peripheral friction sheet ( 19 ) on the disc setting surface ( 3 ), the clamping member ( 15 ) defining an inner recess for receiving the fitting member ( 4 ), when the information medium ( 101 ) is loaded on the turntable, an upper wall of which inner recess is provided with a magnetic means ( 48 ) for attracting the ferrous portion of the movable locking member ( 40 ) causing said movable locking member ( 40 ) to move from said first position to said second position.