Abstract: A combination transducer and water-blocking film for acoustic signaling through ambient water. The water-blocking film has an etched fluoropolymer film and adjacent bonding film interposed between the transducer and the water. Potting material extends adjacent to and is bonded to both sides of the water-blocking film. The film and potting material create an acoustic window. The etched fluoropolymer film is approximately one to two thousandths inch thick and the bonding film is approximately one thousandths inch thick, and the potting material is a polyurethane matrix.

Abstract: Optical fiber coupler for coupling fiber optic elements includes a first fiber optic element extending in a first direction to position a free end thereof in a selected zone, and a second fiber optic element extending into the selected zone from an opposite direction to position a free end of the second fiber optic element in the zone confronting the first fiber optic element free end. A cured optical grade epoxy resin body defines the zone and envelopes the free ends of the fiber optic elements, to effect physical and optical connection between the first and second fiber optic elements. Once cured, the housing material is removed leaving the completed coupler device. The free ends of the fiber optic elements are in close proximity, or in the case of coupling from one strand to a plurality of strands, in enough of a spaced relation, to permit required light diffusion.

Abstract: A encapsulation method of an acoustic sensor module and a resultant lightweight watertight acoustic sensor module for use in towed array retrieval systems. In the method, a composite is cast to encapsulate the support between end plates of the module, an exterior of a passage tube in which the array is retrieved, transducers positioned on the tube exterior and supporting telemetry lines for the transducers. The components, listed previously, are cast into a block of the cured composite such that the arrangement of the components is fixed. Residual composite emitting from an aperture of an end plate allows a conductor for the telemetry lines to be potted into the composite with an end of the conductor free from the composite thereby allowing connection to an external controller or generator.

Abstract: A mounting bracket for removably connecting an acoustic sensor element to an inside wall of a sonar dome of a marine vessel includes a first protrusion bonded at a first end thereof to the inside wall of the sonar dome, extending inwardly therefrom, and provided with a first widthwise extending slot proximate, but spaced from, the inside wall, and a second protrusion bonded at a first end to the sonar dome inside wall and extending generally parallel to and spaced from the first protrusion, the second protrusion being provided with a widthwise extending second slot in a side thereof, the second slot being opposed to and in alignment with the first slot. The slots are adapted to receive portions of the acoustic sensor element and to hold the acoustic sensor element in a position proximate to and removed from the inside wall of the sonar dome.

Abstract: A method for coupling fiber optic elements includes providing a hollow wax housing. A first fiber optic element is inserted in a first direction into the housing to position a free end thereof in the housing. A second fiber optic element is inserted into the housing from an opposite direction to position a free end of the second fiber optic element in the housing confronting the first fiber optic element free end. The housing is filled with optical grade epoxy resin which is permitted to cure, thereby to effect physical and optical connection between the first and second fiber optic elements. The free ends are in close proximity, or in the case of coupling from one strand to many, in enough of a spaced relation to cause needed light diffusion.

Abstract: A mass-loaded coating includes a predetermined mass of powdered lead which s mixed preferably in a ratio of 3:1 with a liquid polyurethane primer. When painted onto the surface of a disc or plate, the coating mass-loads the disc and lowers the resonant frequency of the disc without significantly increasing the physical dimensions of the disc. Thicker consistency adhesives, such as spreadable paste adhesives or thick putty-like adhesives may be substituted for mass-loading objects having irregular surface textures or complex shapes.

Abstract: A submarine buoyant cable antenna having positive buoyancy comprising a cunications antenna electronics package encased in a polymer composition, the polymer composition comprising from about 80 percent to about 85 percent by weight of a room temperature curable thermosetting polymer having a viscosity, before curing, in the range of from about 700 to about 900 centipoise, and from about 15 percent to about 20 percent by weight of microballoons of a size ranging from about 20 to about 100 microns in diameter, the specific gravity of the composition being in the range of from about 0.51 to about 0.65 grams per cubic centimeter to provide the positive buoyancy.

Abstract: There is presented a sonic apparatus for degassing liquids. The apparatus cludes a vessel for receiving and releasably retaining an open-top container and adapted to be closed with the container therein, transducer suspension structure positioned in the vessel, an ultrasonic transducer suspended from the structure and disposed in the container spaced from the walls and bottom of the container and beneath the surface of a liquid contained therein. The apparatus further includes a signal generator outside of the vessel for transmitting power to the transducer, and a vacuum pump for maintaining the vessel interior at a vacuum.

Abstract: A radially-polarized piezoelectric cylindrical transducer is provided. The ransducer has an electrically conductive end cap affixed with a conductive epoxy to one end of a piezoelectric body and a second cap affixed to the other end. The piezoelectric body comprises a layer of piezoelectric material located between an inner and an outer electrode. The outer electrode has an electrode gap which electrically insulates the end cap from the outer electrode. The unit is electrically conductive and permits the attachment of two electrical leads to its exterior, one to the first end cap and the other to the outer electrode of the piezoelectric body. In an alternative embodiment, two conductive end caps are affixed with conductive epoxy to opposite ends of the piezoelectric body. In this embodiment, the inner electrode has an electrode gap which electrically insulates the second end cap from the inner electrode. One electrical lead attaches to each end cap in this alternative embodiment.