Abstract: A disk drive is disclosed comprising a disk comprising a plurality of tracks, a head attached to a distal end of an actuator arm, and a voice coil motor (VCM) operable to rotate the actuator arm about a pivot bearing including a race and a plurality of ball bearings. The VCM is controlled to execute a first jerk seek in a first radial direction so that the ball bearings slip within the race by a first rotation angle. The VCM is controlled to execute a second jerk seek in the first radial direction so that the ball bearings slip within the race by a second rotation angle, wherein the second rotation angle adds to the first rotation angle in order to rotate the ball bearings relative to the race at a reference angle of the pivot bearing.

Abstract: A flexible circuit construction is provided for connecting stationary electrical components to electrical components of a moving actuator within a head and disk assembly of a disk drive. The flexible circuit is integrally formed from a plastic film material carrying a plurality of metal film conductive traces and defining a plurality of regions. A connecting region has a plurality of connection pads for connecting to head conductor wires. A hairpin loop portion is provided adjacent the connecting region for reversing direction of the flexible circuit. An elongated arcuate portion leads from the hairpin loop portion to a fixed substrate portion defining plural connections for mounting a read preamplifier/write driver/head selection integrated circuit device. The connecting region defines for at least one edge region thereof a head wire tube engagement portion having a slotted opening for positioning and securing a head wire tube carrying the head wires.

Abstract: An ultrasonic inspection system for performing in-service inspection of atomic reactors and the like includes a remote inspector including a transducer holding device of novel design and function. The holding device basically comprises an outer housing; an inner housing rotatably retained within said outer housing; an ultrasonic transducer retained within said inner housing; retention means for selectively positioning said transducer within said inner housing; and means for locking said transducer within said inner housing at a selected position.

Abstract: Method and means for protecting earth dams from failure caused by overflow or internal (tunnel) erosion. The invention provides a barrier between the dam and the impounded water in the form of a water-impervious covering for the vulnerable surfaces of the dam. At the least the covering should sheathe the top and upstream face, but better protection is provided by extending the covering to the downstream surface. The covering is flexible to conform to the contours and surface irregularities of the dam, and anchoring means are provided to secure the covering to the dam and to prevent or minimize seepage.