A transducer having opposed first and second conductive plates for application of an electrical potential difference therebetween. An elastomeric dielectric material such as neoprene rubber is disposed between the plates and in contact therewith. The dielectric material has a plurality of pockets of approximate average depth "d" such that, for a given gas maintained within the pockets at a pressure "P", the product Pd is significantly less than the value required to achieve the minimum breakdown voltage for the gas in the pockets. Alternatively, the elastomeric dielectric material disposed between the plates may take the form of a plurality of strips or nodules which separate the plates by a distance "d" as above.

Elastomer membrane enhanced electrostatic transducer

An ultrasonic liquid atomizer is disclosed in which the liquid feed to the atomizing surface extends axially through the atomizer This arrangement enables improved and simplified coupling of the liquid supply tube to the atomizer In a disclosed embodiment, rear and front horn sections sandwich a driver, and an atomizing section is coupled to the front horn section A passage axially extends through the rear section, the driver, the front section and the atomizing section to an atomizing surface The driver includes piezoelectric elements of annular configuration A tubular member or a liquid supply tube itself is received in the passage In a preferred embodiment, the tubular member of the liquid supply tube includes a decoupling sleeve section and a stepped portion adapted to engage a stepped portion in the rear section upon coupling the tubular member or liquid supply tube to the atomizer to draw the front and rear sections together

Ultrasonic liquid atomizer having an axially-extending liquid feed passage

An acoustic well-logging transmitting transducer employing a transmitter portion comprising stacked piezoceramic rings and a resonating metallic plate, the dimension of which determines the frequency, and a conical acoustic reflector for causing reflections to impinge omnidirectionally on the wall of the borehole at an angle to enhance shear wave component propagation. A receiving portion of similar construction can also be employed.

Acoustic well-logging transmitting and receiving transducers

An electro-acoustic transducer according to the invention is of the Tonpilz type comprising a stack of piezo-electric plates placed between a horn and a countermass, and electrodes inserted between the plates. Some of the electrodes are connected to a common excitation or output conductor through phase-shifting circuits which allow the electric voltage of a proportion of these electrodes to be dephased. A logic unit allows the phase-shifting of the electrodes to be distributed within the stack according to several different groupings in dependence upon frequency. One application of the invention is to the construction of long-range power sonars.

Electrio-acoustic transducers

A self-contained probe for testing of buried pipe by analyzing acoustic emissions produced under increasing stress which comprises an elongated tubular body with a hardened metallic point at one end which is placed against the pipe. The body of the probe also contains an acoustic transducer, a preamplifier, and an integral power supply. The probe receives acoustic emissions from the pipe under test, transforms acoustic signals into electrical voltages, preamplifies those voltages, and transmits them to associated facilities for computer analysis.

Remote acoustic probe

A device for attachment of electroacoustic transducers in casings immersed under water and effecting mechanical decoupling through flexible or deformable portions such as rubber or elastomer rings between the vibrating parts and their support.

Marcel Personnic

Papers

Mechanical decoupling device for attachment to electroacoustic transducers