Lockheed Martin Corporation

Raymond Porzio

Todd Charles Gloo

David J Erickson

James D Weigner

A tape cast transducer element assembly comprises a tape cast transducer element including a multi-layer piezoelectric stack diced from a sintered piezoelectric body formed from a plurality of thin film tape layers, the film thin tape layers sintered to produce a final density. A conductive film coats select ones of the thin film tape layers such that conductive layers of different polarities are exposed on opposing sides of the multi-layer piezoelectric stack. Electrodes are coupled to the conductive layers. Electrical leads are coupled to each electrode. A head mass is configured to encapsulate a top portion of the stack. A tail mass is configured to encapsulate a bottom portion of the stack. At least one coupling arrangement extends from a top surface of the head mass through the cross-sectional area of the head mass into the tail mass such that the stack is contained in a rigid assembly under compression.

Tape cast multilayer sonar transducer

A manufacturing process provided herein pertains to a single-piece, multi-layer piezoelectric stack in a sonar transducer element utilized in acoustic arrays requiring many thousands of elements. A slurry formed by mixing ceramics, powders, and binders is filtered, dried and cast into a thin film on a moving substrate. When the film has dried, it is removed from the substrate and layered into piezoelectric stacks. Screening a pattern of conductive platinum ink onto a desired layer forms electrodes. Applied heat and pressure forms a unitary body with electrically accessible layers. Burning removes the binders and sintering produces a final density. Dicing the body exposes the desired electrode polarities. A strip of conductive material is applied to connect the electrodes of like polarity and the ceramic parts are polarized. The transducer elements may be arrayed to conform to the curved surfaces such as a ship's hull.

Method of manufacturing a tape cast multilayer sonar transducer

A transducer comprises a longitudinal tubular member symmetrically disposed about a central longitudinal axis, the tubular member having a slot extending from the front end of said member to the rear end of the member, the slot extending parallel to the central longitudinal axis; a stack comprising a single element or plurality of vibratory elements arranged from a first to a second end and; a mounting arrangement for mounting the said stack across the inner wall of said tubular member on a line relatively transverse to said longitudinal central axis. The mounting arrangement includes a layer of solid lubricant engaging opposite ends of the stack, enabling the stack to move in a direction of the central axis when the stack exhibits vibratory motion.

Longitudinally driven slotted cylinder transducer

A sonar transducer has a head mass at a distal end thereof, a tail mass at a proximal end thereof, a driver in physical contact with the head mass and the tail mass, and a flextensional body incorporating and extending proximally from the head mass. The flextensional body has relatively thin walls or diaphragms with concave surfaces. The sonar transducer may have a fundamental mode having a relatively low resonant frequency, involving substantially only a bending motion of the diaphragms. A second resonant mode, at a frequency higher than the frequency associated with the fundamental mode, involves both a bending motion of the diaphragms and a membrane or breathing motion of the flextensional body, including the head mass. A third, relatively high frequency resonant mode, involves exclusively or substantially exclusively longitudinal motion of the head mass.

Multiple frequency sonar transducer

A longitudinal vibrator-type transducer including: a head mass; a tail mass; a first piezo-resonator positioned between the head and tail masses; and, a coupling member coupling the head mass, tail mass and first piezo-resonator together; wherein, the head mass comprises a piezoceramic plate.

Hybrid transducer

A longitudinally driven slotted transducer has a tubular member with an axial slot extending from one end to the other end. A drive assembly is disposed across the inner wall of the tubular member and supported by journal bearing surfaces extending from opposing sides of the inner wall to locate the drive assembly in a position offset from the longitudinal central axis of the tubular member. The interface between the drive assembly and tubular member comprises a layer of solid lubricant material mounted on the journal bearing type surfaces.

An inverse flextensional projector exhibits a low frequency flexural mode and a higher frequency 'breathing' mode to defeat stealthy targets and to conduct short and long range detection and tracking in littoral waters. The device has much broader bandwidth than conventional flextensional transducers, slotted cylinders and conventional cylinder transducers. The device has a low frequency capability similar to slotted cylinder projectors (SCP) but is broader band and does not suffer from the unsupported gap of SCP projectors. The invention has a more uniform radiation velocity than both SCP and flextensional transducers, making it much less susceptible to cavitation limitations.

Flexural cylinder projector

A longitudinal vibrator assembly comprising at least one piezoceramic, magnetostrictive or electrostrictive transducer ( ) having a coaxial housing ( or ) comprised of at least one slotted or complete cylindrical flexural member vibrating in a circumferential or radial direction and excited by a solid state transduction material.

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Lafayette, NY, United States of America

Raymond Porzio