Abstract: Resistance to shock forces having components acting parallel to the spindle axis of a disk stack is provided by spacing the surface of a circumferential flange of a disk spacer a distance above the surface of a disk in the disk stack which is sufficient to clear the magnetic head and flexure assembly therebeneath during movement thereof during flight to and from a parked position between the confronting surfaces of the circumferential flange and the disk.

Abstract: Apparatus employing ultrasonic energy for detecting and measuring the quantity of gas bubbles present in liquids being transported through pipes. An ultrasonic transducer is positioned along the longitudinal axis of a fluid duct, oriented to transmit acoustic energy radially of the duct around the circumference of the enclosure walls. The back-reflected energy is received centrally of the duct and interpreted as a measure of gas entrainment.One specific embodiment employs a conical reflector to direct the transmitted acoustic energy radially of the duct and redirect the reflected energy back to the transducer for reception. A modified embodiment employs a cylindrical ultrasonic transducer for this purpose.

Abstract: Apparatus for measuring displacements of core components of a liquid metal fast breeder reactor by means of an eddy current probe. The active portion of the probe is located within a dry thimble which is supported on a stationary portion of the reactor core support structure. Split rings of metal, having a resistivity significantly different than sodium, are fixedly mounted on the core component to be monitored. The split rings are slidably positioned around, concentric with the probe and symmetrically situated along the axis of the probe so that motion of the ring along the axis of the probe produces a proportional change in the probes electrical output.

Abstract: A device for generating or sensing transverse elastic bulk waves in solids includes a piezoelectric material engaging a surface of the solid and having a two-fold axis or equivalent symmetry extending parallel to the surface of the solid. A pair of electrodes are located on a surface of the transducer extending perpendicular to the surface of the solid which the material contacts. Each electrode has one or more conductive fingers elongated in a direction parallel to the two-fold axis of the material. The fingers of the electrodes are interlaced. When used as a generator of bulk waves, a source of alternating voltage excites the electrodes. The electrodes thus generate deep surface waves in the piezoelectric material which are transformed into bulk waves in the test solid. Similarly, bulk waves in the test solid are transformed into deep surface waves in the piezoelectric material which may then be sensed by the electrodes.