Patent ID: 8213123

Claim:
In a hard disk drive (HDD) having a base, a swing arm supported on the base so as to be rotatable about an axis of rotation, and a magnetic head supported by the swing arm, an actuator latch system comprising: an integral part of the swing arm that delimits a notch at a rear end portion of the swing arm, the integral part having a peripheral surface two portions of which meet at an inflection; and a latch lever disposed adjacent the rear end portion of the swing arm when the swing arm is in a position at which the magnetic head is parked, the latch lever being mounted to the base so as to be rotatable in opposite directions about an axis of rotation, and the latch lever having at least one main hook and a rebound hook at one end thereof, and a counterbalance at another end thereof, each of the hooks being offset in one direction of rotation of the swing arm when the swing arm is in a position at which the magnetic head is parked, and each of the hooks having a tip that lies between the axis of rotation of the swing arm and a line passing through said inflection in said one direction of rotation, while the swing arm is in a position at which the magnetic head is parked, the part of the swing arm delimiting the notch at the rear end thereof being disposed in between the hooks and the counterbalance, with respect to said directions of rotation, when the swing arm is in a position at which the magnetic head is parked such that the notch moves towards the hooks when the swing arm rotates from said position in said one direction of rotation and the rear end portion of the swing arm moves oppositely towards the counterbalance when the swing arm rotates from said position in the other direction of rotation, the counterbalance being disposed in the path of the swing arm when the swing arm rotates from said position in the other direction of rotation, and wherein the at least one main hook is positioned relative to said integral part of the swing arm such that one of the at least one main hooks engages the swing arm within the notch when the HDD experiences shock that causes the swing arm to initially rotate in said one direction about its axis of rotation while the magnetic head is parked, whereas the rebound hook is positioned relative to said integral part of the swing arm such that the rebound hook engages the swing arm within the notch when the HDD experiences shock that causes the swing arm to secondarily rotate in said one direction about its axis of rotation after rebounding from the counterbalance while the magnetic head is parked, to thereby keep the magnetic head parked.