Abstract: A housing for an electronics package that has a flexible mounting flange that conformably engages the housing to a variety of planar or contoured surfaces is described. The housing, also comprised of an enclosure attached to the flexible mounting flange, provides for the protection and orderly confinement of electronics packages, such as signal conditioning circuitry, disposed within the housing. The housing is inserted into an aperture in a surface, such as the side of acoustic stringed instrument, until the flexible mounting flange engages the planar or contoured surface. The housing is then removably attached to the surface of the aperture.

Abstract: A transducer for a stringed musical instrument utilizes a coaxial structure. A thin layer of a piezoelectric polymer material is extruded about an inner, electrically conductive core. An outer conductor is formed about the piezoelectric polymer material. Polarization of the piezoelectric polymer material is accomplished in conjunction with the extrusion process. The piezoelectric polymer material has an optimized thickness for consistent responsiveness across a desired range of input stimuli, and is capable of maintaining the integrity of the transducer over time. The transducer configured for placement underneath the saddle in a bridge of a stringed musical instrument.

Abstract: A non-fluid-filled streamer cable or towed array for performing seismic surveys in water-covered areas includes a plurality of serially coupled active cable sections. Each active cable section includes an electromechanical cable that contains a single central strain member. A wire bundle is placed around the central strain member for transporting electrical power and data through the active section and an inner protective jacket is formed around the central strain member and wire bundle. A foam material is extruded around the inner protective jacket to provide a predetermined buoyancy to the fully assembled active cable section and an outer protective jacket is formed around the foam jacket. A potting compound is formed between, and bonds to, the inner protective jacket and outer protective jacket to provide a water block at each hydrophone location.

Abstract: An acoustic sensor having one or more segments are electrically coupled to provide a response corresponding to an acoustic pressure applied to the segments. Each segment contains at least one substrate of a desired shape and at least two active members made from a flexible, resilient piezoelectric material, preferably, a polyvinylidene fluoride material. Each substrate includes an enclosed chamber on an outer surface wherein a first active element is within the chamber and a second active element is sealingly placed on the enclosed chamber. The second active element is preferably bonded to a compliant diaphragm sealed to the substrate to provide the sealed chamber. An output response from the first active member is combined with an output response from the second active member to provide for a combined output response having reduced noise. The second active element is covered with a protective layer of a suitable material, preferably a polymer material.

Abstract: The present invention provides an acoustic sensor having one or more segments that are electrically coupled to provide a response corresponding to a hydrodynamic pressure applied to the segments. Each segment contains a substrate of a desired shape with a concavity on an outer surface that is sealingly enclosed by an active member made from a flexible, resilient piezoelectric material. PVDF material is preferably used as the piezoelectric active element. The active element may be bonded to a compliant diaphragm sealed to the substrate to provide the sealed chamber. The active member is covered with a protective layer of a suitable material, preferably a polyvinyl material. In one embodiment, the diaphragm includes a standoff ledge and is placed on the outer surface of the substrate to define the sealed chamber between the diaphragm and the outer surface of the substrate.

Abstract: The present invention provides an acoustic sensor having one or more segments that are electrically coupled to provide a response corresponding to a hydrodynamic pressure applied to the segments. Each segment contains a substrate of a desired shape with a concavity on an outer surface that is sealingly enclosed by an active member made from a flexible, resilient piezoelectric material. PVDF material is preferably used as the piezoelectric active element. The active member is covered with a protective layer of a suitable material, preferably a polyvinyl material. A single segment may be used as a sensor or a plurality of suitably configured segments may be suitably coupled to form the sensor. The sensor may be used as a hydrophone on a hydrophone cable commonly used for performing seismic surveys for geophysical exploration. In such applications, a plurality of hydrophones are placed equally spaced along the cable. In the preferred embodiment, two hydrophone segments are securely be placed around the cable.

Abstract: A pressure compensated hydrophone assembly consists of a hollow mandrel that has an outer surface. The central portion of the outer surface of the mandrel defines a concavity. A flexible, resilient piezoelectric film is wrapped several times around the mandrel. The volume between the inner wrap of the film and the concavity on the outer surface of the mandrel serves as a pressure compensation chamber. The hydrophone is responsive to varying hydrodynamic pressure fields but is substantially inert to acceleration forces, localized impacts and variations in hydrostatic pressure.

Abstract: A piezoelectric film strip is wrapped a plurality of times around a flexible inert mandrel that has standoff collars on each end. The film-wrapped mandrel is hermetically sealed inside a hollow rigid inert cylinder. Electrodes provide electrical communication with the film strip which forms the active element of the transducer. Variations in hydrodynamic pressure flex the film strip in tension to generate a voltage.

Abstract: A pressure sensing transmitter is provided that has high overpressure protection. The transmitter includes an housing having a first cell, a second cell, a sensing chamber, first and second pressure signal receiving means, and a differential sensor chip for measuring the pressure differential between the first and second pressure signal receiving means. Each cell further includes a cylinder with a clearance of an overpressure diaphragm mounted on the housing, an isolation diaphragm mounted on the other face, and a channel coupling the overpressure and isolation diaphragm and further coupling one cell to the first pressure signal receiving means and the other cell to the second pressure signal receiving means. Each overpressure diaphragm is positioned such that an overpressure protection cavity is formed between it and the housing. The first cell cavity is further coupled to the second pressure signal receiving means and the second cell cavity is further coupled to the first pressure signal receiving means.

Abstract: An improved cantilever support beam assembly for a load cell and the like having a longitudinally extending support beam with two openings extending through the sidewalls of the beam. The openings are independent from one another and separated by a web. Strain gages, are mounted on the concave portions of the openings which are adjacent one another.

Abstract: A liquid filled pressure transducer which utilizes a self activating lip seal type valve to create a sealed cavity within the transducer to prevent the flow of liquid from behind the pressure diaphragm and thereby prevent distortion of the diaphragm under overload conditions. A mechanical stop prevents excess displacement of the sensor element.

Abstract: An improved cycle monitor is disclosed for measuring the peak force exerted by a machine in each of a series of operating cycles. The force exerted by the machine is measured and applied to a peak detector which stores a signal proportional to the highest force exerted by the machine. The peak detector is automatically reset at the beginning of each cycle and the peak detector output is transferred to and stored in a suitable utilizing device, such as a display and alarm circuit, after the highest pressure occurs in each cycle.

Abstract: A column type bonded strain gage load cell having improved linearity and output is achieved using a column having a pair of opposed transverse bores which create a web therebetween. The web has a relatively high strain as compared to the circumferential strain of an unbored column. Strain gages bonded to the web, in combination with strain gages bonded at selected regions on the column provide improved linearity and increased output.

Abstract: A parallel beam load cell wherein sensitivity to transverse load position changes is reduced by changing the shape of one of the beams in the vicinity of one strain gage element whereby the neutral axis of said beam is changed with respect to said strain gage element. Longitudinal load position sensitivity is reduced by changing the cross sectional area of one of the beams adjacent one strain gage element.