Abstract: In a preferred embodiment, an inter-element mounting for ceramic elements in a piezoelectric transducer stack, which mounting includes two metal plates disposed between adjacent surfaces of the ceramic elements. The metal plates are cantilevered with respect to the surfaces of the ceramic elements, such that a substantial portion of the areas of the plates between the adjacent surfaces is unsupported and, therefore, the plates have a high degree of resilience. This structure provides controlled vibrational characteristics, structural integrity for high hydrostatic pressure, versatility in design for spurious resonance suppression or elimination, dampening, and special utility for pressure gradient hydrophone stacks.

Abstract: A sonobuoy has several components slidably mounted in an elongated tube. The components are longitudinally stacked one above the other at the lower end of the tube when the sonobuoy is in a pre-deployed state and are caused to slide longitudinally upwardly in the tube during sonobuoy deployment to provide a predetermined longitudinal spacing between the components when the sonobuoy is deployed. The components typically include an electronics canister, acoustic wave phase controls and one or more active electroacoustic transducers. The components are attached to a plurality of flexible support cables. The cables are attached at their respective upper ends to the bottom of the canister and are attached at their respective lower ends to the bottom of the tube. The cables are collapsed during the pre-deployed state and tautly extended during the deployed state. Axial guide strips are affixed to the inner surface of the tube.

Abstract: An electroacoustic transducer ring has an inner vibratile surface defining a ring cavity with a plurality of arcuately spaced electrodes affixed thereto. Planar partitions are placed in the ring cavity. The partition edges are parallel to the ring axis and are attached by a resilient strip to the ring inner surface in the arcuate spacing between the electrodes. The partitions have substantially continuous radial surfaces and when the partitions are substantially coextensive in the axial direciton with the ring axis optimal chordal and diametral isolation between the electrodes is provided.

Abstract: Omnidirectional sonic transducers suitable for underwater operation as either hydrophones (listening devices) or projectors (sonic sources) are disclosed. The transducing device has a hollow resonant cavity with at least one flexural disk mounted therein in acoustic communication with both the interior and exterior of the cavity. The cavity also has at least one aperture providing acoustic coupling between the cavity interior and exterior, and a pliant lining covering substantially the entire cavity inner surface except for flexural disk surfaces and the aperture to detune the natural cavity resonance by reducing the rigidity of the cavity inner surface, thereby improving the overall frequency response characteristics of the transducing device.

Abstract: A sonobuoy has several components slidably mounted in an elongated tube. The components are longitudinally stacked one above the other at the lower end of the tube when the sonobuoy is in a pre-deployed state and are caused to slide longitudinally upwardly in the tube during sonobuoy deployment to provide a predetermined longitudinal spacing between the components when the sonobuoy is deployed. The components typically include an electronics canister, acoustic wave phase controls and one or more active electroacoustic transducers. The components are attached to a plurality of flexible support cables. The cables are attached at their respective upper ends to the bottom of the canister and are attached at their lower ends to the bottom of the tube. The cables are collapsed during the pre-deployed state and tautly extended during the deployed state. Axial guide strips are affixed to the inner surface of the tube.

Abstract: A stacked phased array type of transducer has a single electroacoustic transducer element supported intermediately of an elongated tube having a plurality of ports and an end wall at each end thereof for transmitting and receiving acoustic waves broadside the longitudinal axis of the array tube. The element has a first vibratile surface in direct acoustical communication with the external transmission medium and a second vibratile surface in direct acoustical communication with the tube internal transmission medium. The tube is provided with at least one annular port spaced longitudinally from each end of the element for providing acoustic coupling between the internal and external transmission mediums with the tube interior providing acoustic transmission paths internally of the tube communicating between the second vibratile surface and the external transmission medium at each one of the ports.

Abstract: A substantially flat and disc-like shaped sound transducer for sensing sound waves in a fluid transmission medium and having directional and omnidirectional response characteristics to the sound waves. The sound transducer having a circular vibratile plate divided into quadrantal portions and having a surface adapted to be coupled to the transmission medium for providing sound wave motion in the portions dependent upon, and in response to, sound wave travel in the transmission medium and having a plurality of electroacoustic transducer elements coupled to the quadrantal portions of the vibratile plate for providing electrical output signals in response to the wave motions in diametrically opposed quadrantal portions. The sound transducer responding to incident sound waves having wavefront travel directions, in the transmission medium, substantially parallel to the coupled surface.