Patent ID: 6807721
Filing Date: 2004-10-26
Classification: G11B,Y10T

Abstract:
A method for forming a disc stack assembly comprising steps of:(a) providing a spindle motor hub having an annular ring recess, a number of discs, a disc shaped clamp plate comprising an outer disc engagement portion disposed between an annular hat flange and an inner ring engagement portion, the inner ring engagement portion surrounding a clamp plate central opening while providing a plurality of hook flanges confining a retaining ring placed within the plurality of hooked flanges; (b) loading the number of discs onto the spindle motor hub, the number of discs including a topmost disc; (c) supporting the clamp plate with the confined retaining ring adjacent the spindle motor hub so that a portion of the spindle motor hub projects through the clamp plate central opening, so that the inner ring engagement portion is brought adjacent the annular ring recess, and so that the outer disc engagement portion is brought adjacent the topmost disc; (d) applying an axially directed force to the clamp plate at a position adjacent the inner ring engagement portion to conically deform the clamp plate; (e) installing the retaining ring in the annular ring recess of the spindle motor hub; and (f) removing the axially directed force of applying step (d) so that the inner ring engagement portion of the clamp plate applies a first moment force against the retaining ring while the outer disc engagement portion of the clamp plate applies a second moment force as an axially directed clamping force upon the topmost disc as the clamp plate attempts to return to an undeformed state.