Abstract: An apparatus and method for securing an information storage disc within a disc drive incorporates a spindle motor, a rotatable spindle hub, a disc clamp and a disc clamp nut. The disc clamp is positioned on the rotatable spindle hub to clamp the information storage disc to the spindle motor. The disc clamp defines a middle annular raised portion for accepting a predetermined pre-load force to compress the disc clamp down onto the information storage disc. The pre-load force is perpendicular to the disc clamp, and is applied symmetrically around a spindle motor axis of rotation. The disc clamp nut includes a flat engagement surface that secures the pre-loaded disc clamp to the hub. The pre-load force is released once the disc clamp nut is positioned so as to secure the disc clamp to the hub of the disc drive spindle motor. A series of substantially parallel engagement surfaces on the disc clamp nut, disc clamp and hub ensure that the pre-load force is uniformly applied to the information storage disc.

Abstract: An improved locking system for securing the actuator of a disc drive at a park position. The locking system includes a rotatable lock mechanism that is normally biased to a lock position. When the actuator is moved to the park position, a cooperative lock feature on the moving portion of the actuator interacts with a pawl feature on the rotatable lock mechanism to momentarily overcome the biasing force. When the lock feature on the moving portion of the actuator moves beyond the pawl feature, the bias force acts to return the rotatable lock mechanism to its locked position with the pawl feature engaging a cooperative surface on the lock feature to lock the actuator at the park position against a lightly compressed compliant limit stop and to maintain the actuator at the park position in the presence of applied mechanical shocks.