Abstract: A shock resistant disk drive has a balanced rotary actuator and a disk assembly rotatably mounted to its base. The rotary actuator is latched with its transducer in a parked position relative to the disk assembly, by a monostable balanced rotary inertia latch, also rotatably mounted to the base, which in its monostable latched position is torque coupled in torque opposition to said rotary actuator in parked position. The balanced rotary actuator and the balanced rotary inertia latch, being rotatably mounted to the base, respond to rotary shock in the same rotational sense. The moment of inertia of the balanced rotary inertia latch and the ratio of the opposed torque moment arms in the torque couple are chosen so that in the presence of rotary shock on said base, rotation of said balanced rotary actuator relative to said base and rotation of said balanced rotary inertia latch relative to said base, is zero.

Abstract: A rotary accelerometer has capacitively coupled rotary and fixed thin film electrodes fixed to a substrate. The rotary electrode is angularly flexible and has a central hub secured to the substrate and spoke electrodes radially extending from the hub. Elongated electrodes are fixed to the substrate in circumferential positions on each side of each spoke electrode and in the same plane as the spoke electrodes. The rotary electrode, having a mass and being angularly flexible, responds to angular acceleration to differentially change the gaps between its spoke electrodes and the adjacent fixed electrodes. The fixed electrodes are energized with rectangular wave voltages of opposite phase. The sum of these voltages in the spoke electrodes is a function of the difference in the gaps which, in turn, is a function of the angular inertia of the rotary electrode.

Abstract: An actuator lock for a disk drive in which fixed air vanes projecting between a adjacent disks divert air flow, generated by disk rotation, into a narrowing passage adjacent the disks to impinge upon an air vane forming part of a rotatably mounted actuator lock, to angularly move the actuator lock to release an actuator assembly for movement of the magnetic heads thereon in track seeking and track following operations.

Abstract: A disk drive is provided in which the arm/head structures of the armstack are mounted in circumferentially spaced pairs, on individual projections of a rotatable actuator. The mounted pairs of arm/head structures project between the confronting disk surfaces of adjacent disks with the heads displaced from one another in a direction longitudinally of the arms and with the active faces of the heads pointing in opposite directions and in confronting or yielding contact with an adjacent disk surface. The magnetic heads are at different radial locations on respective confronting surfaces of adjacent disks of the disk stack as the actuator rotates, in all radial track positions except one track position.