Removable disc media

Claim 2

Apparatus for mounting a hub on a spindle, including: a rotatable hub including a circumference collar, a centering element at the hub center, and extend axially thereof, and a connecting means for maintaining said collar in a normal position with respect to said centering element; an armature plate mounted with respect to the collar constrained against any substantial axial movement relative thereto; a spindle rotatable on a central axis, and means defining an armature plate-receiving surface integral with said spindle; a forcing means for urging said armature plate axially inward toward a full engagement against said armature plate-receiving surface; said spindle including a receiving means for engaging said centering element whenever said hub is at least approximately centered on said spindle and for guiding said element, when in contact therewith, toward said central axis responsive to said forcing means said connecting means being substantially rigid radially of said hub, but deformable elastically to allow axial displacement of said collar from said normal position with respect to said centering element; whereby said collar and said armature plate, with said centering element and said receiving means in contact are displaced responsive to said forcing means axially inward from said normal position, thereby elastically deforming said connecting means prior to said full seating of said armature plate against said armature plate-receiving surface; wherein said collar is movable radially of said armature plate so as to allow said hub to move radially independently of said armature plate toward a centered position on said spindle as said centering element is guided toward said central axis thereby to reduce the radial stiffness in said connecting means required for hub centering.

Claim 3

The apparatus of claim 1 including: means for limiting the movement of said armature radially of said hub.

Claim 4

The apparatus of claim 2 wherein: said means for limiting movement of said armature include a plurality of bosses formed in said hub, and means defining openings in said armature, each opening associated with one of said bosses and larger in diameter than its associated boss.

Claim 5

The apparatus of claim 1 wherein: said forcing means includes a permanent magnet attached to said spindle, and said armature is of a magnetizable material.

Claim 6

For centering a magnetic disc on a spindle in a magnetic disc reading and recording device, apparatus including: a spindle, means defining an armature plate-receiving surface integral with said spindle, and means for driving said spindle rotatably about a central axis; a rotatable hub adapted for carrying at least one magnetic disc said hub including a circumferential collar, a centering element at the hub center and extending axially thereof and a connecting means for maintaining said collar in a normal position with respect to said centering element; an armature plate mounted to the collar and constrained against any substantial axial movement relative thereto; and a forcing means for urging said armature plate axially inward toward a full engagement against said armature plate-receiving surface; said spindle including a receiving means for engaging said centering element whenever said hub is at least approximately centered on said spindle, and for guiding said element, when in contact therewith, toward said central axis responsive to said forcing means; said connecting means being substantially rigid radially of said hub, but deformable elastically to allow axial displacement of said collar from said normal position with respect to said centering element; whereby said collar and said armature plate, with said centering element and said receiving means in contact are displaced responsive to said forcing means axially inward from said normal position, thereby elastically deforming said connecting means prior to said full seating of said armature plate against said armature plate-receiving surface; wherein said collar is movable radially of said armature plate so as to allow said hub to move radially independently of said armature plate toward a centered position on said spindle as said centering element is guided toward said central axis thereby to reduce the radial stiffness in said connecting means required for hub centering.

Claim 7

For centering a magnetic disc on a spindle in a magnetic disc reading and recording device, apparatus including: a spindle, means defining an armature plate-receiving surface integral with said spindle, and means for driving said spindle rotatably about a central axis; a rotatable hub adapted for carrying at least one magnetic disc said hub including a circumferential collar, a centering element at the hub center and extending axially thereof and a connecting means for maintaining said collar in a normal position with respect to said centering element; an armature plate mounted to the collar and constrained against any substantial axial movement relative thereto; and a forcing means for urging said armature plate axially inward toward a full engagement against said armature plate-receiving surface; said spindle including a receiving means for engaging said centering element whenever said hub is at least approximately centered on said spindle, and for guiding said element, when in contact therewith, toward said central axis responsive to said forcing means; said connecting means being substantially rigid radially of said hub, but deformable elastically to allow axial displacement of said collar from said normal position with respect to said centering element; whereby said collar and said armature plate, with said centering element and said receiving means in contact are displaced responsive to said forcing means axially inward from said normal position, thereby elastically deforming said connecting means prior to said full seating of said armature plate against said armature plate-receiving surface; wherein said collar is movable radially of said armature plate so as to allow said hub to move radially independently of said armature plate toward a centered position on said spindle as said centering element is guided toward said central axis thereby to reduce the radial stiffness in said connecting means required for hub centering.