Seismic streamer cable Western Geophysical Co of America British Patent 1,230,701 (1971)Filed 21 March 1969 Each section of a marine seismic streamer cable has a primary array of hydrophones connected in parallel over the length of the section and two secondary arrays each extending over half the section. Sections have oil-f'filed plastics jackets (eg pvc) and end seals. The streamer cable is trailed at a predetermined depth by a paravane. Ultrasonic inspection system International Meehanite Metal Co Ltd British Patent 1,230,819 (1971 ) Filed 7 Aug 1969 The degree of modularity of the graphite in a batch of molten iron for casting is assessed ultrasonically on a sample billet. Fluid flowmeters R. B. Jacobs British Patent 1,219,887 (1971) Filed 10 Feb 1969 A system for measuring density, mass flowrate and volume flow-rate of a fluid comprises a pressure-sensitive piezoelectric transducer which is vibrated in a direction transverse to the longitudinal axis of a fluid duct, the amplitude of the resultant inphase component of the transducer output signal being proportional to fluid density. Tire transducer is pre-loaded to compensate for effects of static pressure and a filter removes parasitic components from the transducer output signal. Electromeehanieal delay lines Thomson-CSF British Patent 1,219,530 (1971 ) Filed 17 Nov 1969 A method of manufacturing a plurality of strip delay lines to a desired delay time, precise adjustment being made by a hammering, rolling or stretching operation. Moving-coil transducers Standard Telephones & Cables Ltd British Patent 1,219,918 (1971 ) t:iled 8 August 1968 Sound equalization in a moving-coil electroacoustic transducer is achieved by one or
more holes in front cover and by a damping grid in the form of an annular trough having one or more boles. Ultrasonic probes, inspection devices: acoustic lenses S. T. D. Services Ltd British Patent 1,222,355 (1971)Filed 18 March 1968 A probe for use in flow detection incorporates a flat piezoelectric transducer and a sound refractive lens in acoustic contact with the transducer, the lens being shaped to produce a focused ultrasonic beam of elongate cross-section with a substantially uniform intensity distribution across the section at the focus. The transducer is a lead zirconate titanate element (20 x 5 mm) supported on a base of tungsten-loaded epoxy material. Intruder alarms Advanced Devices Laboratory Inc British Patent 1,222,871 (1971) Filed 23 April 1968 A system for detecting the presence of certain objects within a volume under surveillance when the object moves with a velocity within a selected range, comprises a Doppler system with radiation field covering said volume. This space may be monitored by acoustic waves or radio waves. Acoustic delay lines British Electronic & Associated Industries Ltd British Patent 1,223,534 (1971 ) Filed 19 August 1971 To eliminate second or third reflection signals in a delay device comprising a glass body with input and o u t p u t piezoelectric transducers, a stepped reflecting surface is provided. It is arranged that reflection signals arrive in phase opposition to each other at the o u t p u t transducer. Electromeehanical delay lines Tesla, Narodni Podnik British Patent 1,224,728 (1971) Filed 20 March 1969 A delay line comprises a hexagonal prism of glass or ceramic having piezoelectric input and output transducers on sides inclined at 45 ° .
Ultrasonic inspection devices Dr J. U. 1t. Krautkramer Ges fur Elektrophysik British Patent 1,224,821 (1971) Filed 6 Marcia 1969 Apparatus for rapidly establishing and maintaining accurate positioning of transducers relative to the surface of a workpiece advancing through a non-destructive testing station.
Acoustic fluidic oscillators Campagnie des Compteurs British Patent 1,223,657 (1971) Hled 21 Eeb 1969 A device for distinguishing between two gases such as nitrous oxide and oxygen (both used in anaesthesia) causes flow to interrupt and re-make alternately, producing an alarm signal with the aid of an acoustic resonator.
Well-logging: ultrasonic couplings Mobil Oil Corp British Patent 1,221,471 II971 ) Filed 1 March 1968 Mechanism permits 360 ° rotation of radiantenergy transducer assembly of logging tool without significant attenuation of the energy by the tool. The radiant energy may be nuclear, acoustic or light. In the acoustic embodiment, directional lead zirconate titanate transmitting and receiving transducers are glued to flat faces on two generally cylindrical members.
Acoustic delay lines Sanders Associates Inc British Patent 1,221,623 (1971)Filed 13 Oct 1969 A delay line which may be continuously variable comprises a conventional electron gun. An electrostatic beam deflection system has lateral and longitudinal plates for directing the beam on to an electroacoustic transducer constituting tile delay element.