Image Acoustics, Inc.

Other

Raytheon Company

Hazeltine Corporation

Ambient Corporation

John L Butler

Alexander L Butler

Arthur F Clark

Frank D Fratantonio

Arthur E Clark

William M Pozzo

Kenneth Rodberg

Jethro H Tannis

Thomas R Egan

An electro mechanical piezoelectric under water sound acoustic projector transducer which does not interfere with adjacent hydrophone reception and is mainly controlled at the electrical input is presented here. The method recognizes that the main interference with the adjacent hydrophone is mostly due to the resonance of the projector when not transmitting and is excited by the incoming acoustic wave reflected from the target signal originally initiated by the projector. Means for accomplishing this are shown to be simple to implement on current or new projector systems. The process uses an electrical resistor that absorbs the incoming acoustic wave as if the resistor were a mechanical damper and the projector transducer were acoustically transparent.

Underwater acoustic projector transducers

A low frequency underwater sound electro-mechanical transduction bender apparatus for radiating sound at deep submergence depths and including at least one piezoelectric bilaminar or trilaminar beam or disc having opposed support ends; a pair of piezoelectric structures that each have sides that are respectively connected at the opposed support ends of the beam or disc. The piezoelectric bilaminar or trilaminar beam or disc is driven by the pair of piezoelectric structures. The apparatus further includes a housing that contains the piezoelectric bilaminar or trilaminar beam or disc and the pair of piezoelectric structures, as well as an internal fill of a fluid substance. The housing further defines a reflective rear plate that is positioned opposite to the piezoelectric bilaminar or trilaminar beam or disc for reflecting off of it and returning back to the rear section of the frontal disc or beam or a reflective surface from which back radiation from the bender disk reflects at an angle of 45 degrees and travels radially outward or a reflective surface from which back radiation of the bender disk reflects at an angle of 45 degrees and travels radially outward.

Deep submergence bender transduction apparatus

An underwater acoustic transducer that is capable of radiating acoustic energy at low frequencies. A transducer which is a resonant low frequency bender-type transducer driven at its end supports by a piezoelectric stack of material operating with inner and outer parts driven in opposite directions creating a bending motion of a radiating beam, plate or disc. The small piezoelectric motions at the beam supports are magnified by the leveraged motion of the bending beam(s) creating significant output at low frequencies.

End driven bender transduction apparatus

Electro-mechanical transducers are used to actively cloak a targeted object in a way that absorbs incoming waves without reflection, sends them out the opposite side of the target and returns the wave without leaving a shadow behind the target. The present invention pertains to an improvement in the cloaking of an object without requiring the use of special materials for the object itself and allows the use of SONAR and other possible transducer systems that would be covered and rendered ineffective with passive cloaking materials. Other means are also provided for extending the bandwidth as well as increasing the efficiency for cloaking or other transducers.

Active cloaking with wideband transducers

Electro-mechanical transducers are used to actively cloak a targeted object in a way that absorbs incoming waves without reflection, sends them out the opposite side of the target and returns the wave without leaving a shadow behind the target. The present invention pertains to an improvement in the cloaking of an object without requiring the use of special materials for the object itself and allows the use of SONAR and other possible transducer systems that would be covered and rendered ineffective with passive cloaking materials.

Active cloaking with transducers

An electro-mechanical transducer is disclosed, which provides a very low frequency wide band response from a bender (or benders) using piezoelectric cantilevers or center mounted free edge disc, providing additive output between the resonant frequencies achieving this response at great depths under equivalent free flooded conditions with additionally improved response with silicone rubber to reduce the acoustic cancellation associated with the dipole mode of vibration of the bender.

Quad and dual cantilever transduction apparatus

A modal piezoelectric transducer that is constructed with at least three multi section piezoelectric structures to which a shell with equal concave or indentation sections is attached at the intersections of the piezoelectric structures providing magnified displacement to attached pistons and greater loading of the medium on to the piezoelectric structures producing greater output and a lower resonance frequency. A doubly steered array of steerable modal piezoelectric transducers is steered in the same direction as the array is steered.

Doubly steered acoustic array

An electro-mechanical transducer provides a very low frequency wide band response by using a quad configuration of piezoelectric cantilevers, providing additive output between the resonant frequencies of the cantilevers and achieves this at great depths under free flooded or oil filled conditions.

Cantilever type acoustic transduction apparatus

An electro-mechanical transducer is disclosed, which provides a wideband response by activating successive multiple resonant frequencies in a way which provides additive output between the resonant frequencies with reduced cancellation below the first resonance and means for controlling the response by reducing the voltage drive. A multiply resonant wideband high output transducer is disclosed.

Stepped multiply resonant wideband transducer apparatus

An electro-mechanical transducer, which provides dipole motion from its housing which is driven by a bender transducer attached to the housing at the outer edge and attached to an inertial mass at its center providing a lower resonance frequency, lower mechanical Q and enhanced motion and acoustical source level.

Mass loaded dipole transduction apparatus

An electromechanical transducer which provides orthogonal translated motion to a piston through an attached lever arm connected to and driven by at least two electromechanical cantilever members, mounted on a separate inertial tail mass, and which under full array loading conditions provide a reduced resonance frequency that yields velocity control in the vicinity of that resonance.

Cantilever driven transduction apparatus

A transduction apparatus, which employs an array of individual transducers that generates multiple acoustic radiation modes, is described. These modes are used together to yield directional steered beam patterns. In one embodiment separate transducers, clustered in the form of a ring array, are used together to generate wide and narrow cardioid type beam patterns through combined monopole, dipole and quadrupole radiation modes in the medium, along with at least one tail mass.

Modal acoustic array transduction apparatus

An electro-mechanical transducer, which provides radial amplified multiple piston motion is formed from attached multiple lever arms and multiple electro-mechanical drivers. The piston motion is amplified by lever arms, which are attached to electro-mechanical drivers, such as piezoelectric or magnetostrictive drivers, which oscillate in a radial direction in unison with the applied voltage. A minimum of three pistons, three lever arms (or shells) and three drivers may be used. A preferred embodiment, uses four pistons, four lever arms (or shells) and four drivers. As a result of both the magnified motion of the lever arms (or shells) and the large acoustic radiating area of the multiple pistons, the transducer provides a means for a high-source level from a compact low-frequency broadband transducer.

Multi piston electro-mechanical transduction apparatus

An electro-mechanical transducer is disclosed, which provides a wideband response by activating successive multiple resonant frequencies in a way which provides additive output between the resonant frequencies. A three mode wideband high output transducer is also disclosed along with an electro-mechanical feedback system which provides a smoothed response as well as array control under multiple element usage.

Multiply resonant wideband transducer apparatus

An electro-mechanical transducer, which provides beam patterns synthesized from the vibration modes of the transducer. A preferred form of the transducer is a short piezoelectric tube or ring with separate electrodes spaced around the ring for specific excitation of the monopole, dipole and quadrupole modes of vibration. Operation of the transducer in the region between the dipole and quadrupole modes yields a system with a nearly constant beam pattern and transmitting response. The arrangement allows a simple directional steered beam pattern from a single transducer.

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Cohasset, MA, United States of America

John L Butler