Abstract: A sector scanner having an oscillating transducer element includes a motor and rotating shaft, a crank attached to an end of the shaft, and a linkage connecting the crank and the oscillating transducer element whereby rotation of the shaft is translated to oscillation of the transducer element. Vibration from the oscillating transducer element is minimized by reducing the mass of the oscillating element and employing harmonic motion of the transducer element.

Abstract: Positioning apparatus for vertically moving a scanning assembly includes a vertical support, a first arm pivotally attached to the support and to the scanning assembly, and a second arm pivotally attached to the support and to the scanning assembly with the first and second arms being parallel. A counter-balance is provided and is attached to the support by third and fourth arms which are pivotally attached to the support and to the counter-balance.

Abstract: A sector scanner which compensates for fluid leakage from the sealed transducer cavity includes a bladder in the cavity which is vented to the outside atmosphere whereby the bladder expands to compensate for the loss of fluid and a differential pressure between the cavity and the outside atmosphere is avoided. Alternatively, a fluid filled bladder is provided outside of the cavity and a port in the bladder is in fluid communication with the sealed cavity whereby fluid lost from the cavity is replaced by the fluid filled bladder. The bladder can be expandible with the fluid therein being under pressure.

Abstract: An ultrasonic sector scanner which utilizes rotating transducers uses an optical encoder for generating indexing signals. A slip-ring and brush assembly interconnects the transducers and electronic circuitry within the scanner.

Abstract: An ultrasonic sector scanner using rotating transducers includes a transducer support wheel having a circumferential rim surface with a plurality of recessed seats within the circumferential surface for receiving inwardly facing transducers. The wheel and recessed seats provide accurate alignment of the transducers and acoustic mirrors direct ultrasonic energy between the transducers and ports.