Abstract: A multi-layer piezoelectric transformer (PT) is provided that is capable of achieving high mechanical momentum and, therefore, is capable of high energy transmission. The PT has a plurality of layers arranged as a composite structure. The outermost portions of the PT comprise the input portions, which are bonded to the central output portion of the PT. The construction and anisotropic nature of the PT allows it to be driven at the longitudinal resonant frequency of the PT corresponding to its overall thickness, which increases the achievable gain and power density of the PT.

Abstract: A piezoelectric transformer is provided having segmented electrodes on one or both faces of a piezoelectric ceramic disk. Application of a voltage sequentially to one or more adjacent segments forms a travelling wave in the disk. Application of a voltage to alternate segments forms a resonant standing wave in the disk. The transformer may be configured with a resonant feedback circuit that provides step up voltage transformation, and may provide voltage to multiple loads.

Abstract: A multi-layer piezoelectric transformer (PT) is provided having an insulation layer having an input electroactive ceramic layer bonded to one of its major faces and an output electroactive ceramic layer bonded to its other major face. The input layer is electroded on both major faces and is poled in the thickness direction. The output layer has segmented electrodes patterned on its two opposing major faces and portions of the output layer are alternatingly poled in opposite directions across the output layer's thickness. The configuration of the poling and electrodes places adjacent portions of the output layer electrically in series.

Abstract: A multilayer piezoelectric transformer is provided using the longitudinal vibration modes for step-up voltage conversion applications. An input portion polarized to deform in a longitudinal plane is bonded to an output portion. The deformation of the input portion is mechanically coupled to the output portion, which deforms in the same longitudinal direction relative to the input portion. The output portion is polarized in the thickness direction relative its electrodes, and piezoelectrically generates a stepped-up output voltage.

Abstract: A method and apparatus for manufacturing prestressed piezoelectric actuators which maximizes output, and increases the precision and efficiency with which the multi-layer actuators are made. Individual layers of the piezoelectric actuators are automatically stacked and registered with respect to each other within press members prior to bonding the layers to each other with a thermoplastic adhesive. Compressive force is applied while heat is conductively transferred from a heating element to the actuator in order to raise the temperature of each of the layers above the melting point of the thermoplastic. The temperature of the heating element is then decreased until the temperature of the actuator layers drops to below the melting point of the thermoplastic adhesive, thereby bonding the layers. Compressive force is then released, and the actuators are removed, further cooled and polarized.

Abstract: A circuit including a transformer, preferably a laminated piezoelectric transducer, in combination with a positive feedback amplifier circuit, capable of serving: 1) to produce either an audible or ultrasonic signal; or 2) as an energy source capable of driving an auxiliary high voltage device with an initial and continuing low voltage source such as a battery.

Abstract: A sewage pumping apparatus is provided for delivering sewage collected by gravity in a wet well to a force main. The sewage pumping apparatus comprises a motor controlled pump in fluid communication with the wet well for supplying sewage to the force main via a pinch valve. A fluid parameter sensing device is provided at the outlet of the pump for producing an electrical signal output proportional to the sensed fluid parameter (pressure or flow rate). A Digital Process Controller (DPC) receives and compares the electrical signal from the fluid parameter sensing device to a system setpoint and produces a signal outputs to open or throttle the pinch valve in accordance with the desired system backpressure to prevent overloading or cavitation of the pump and to clear blockages in the system.

Abstract: A breastfeeding breast support roll is constructed of an outer layer of soft, absorbent material filled with compressible and or resilient material. The breastfeeding breast support roll is placed underneath the breastfeeding breast, allowing a woman to breastfeed an infant in an upright position without difficulty. The breastfeeding support roll lifts the breast upright and directs the nipple outward to enable proper positioning of the baby to latch onto the nipple for proper breastfeeding. The breastfeeding breast support roll promotes successful breastfeeding efforts by providing a breastfeeding aid that is portable, compact, convenient and simple to use and position.

Abstract: A multi-layered piezoelectric electrical energy transfer device has its input and output sides electrically isolated from each other. As a transformer, the device provides step-down voltage conversion while the output signal preserves the input signal frequency in a broad bandwidth. For telecommunications applications, the transformer can provide impedance matching with transmission lines, which minimizes line losses and echoes that seriously degrade high-speed data transmission. The piezoelectric transformer also provides a uniform voltage transformation ratio (Vout/Vin) over wide frequency ranges, and is adaptable for simultaneous audio and data signal telecommunications applications requiring wide bandwidth service.

Abstract: An anti-lock braking system includes a moveable member to be braked and a friction brake for applying a braking force. A controller actuates the friction brake in accordance with braking force demands. Braking force demands are determined by the controller by electrical input signals received from a signal generator that is mechanically linked to the brake pedal, as well as by signals from a slip sensor. The slip sensor records values from wheel speed sensor and computes values that may indicate a slippage condition. Based on the recorded and computed values, the slip sensor and sends electric signals to the controller. The friction brake includes a prestressed piezoelectric element that is lightweight, less cumbersome, and highly controllable as compared with prior anti-lock braking devices, and is actuated via electrical signals rather than a mechanical system.

Abstract: A thickness mode piezoelectric transformer is provided that has masses attached to opposing faces of the transformer. The end-masses increase the thickness of the transformer and decrease its resonant frequency. The end-masses increase the magnitude of resonant vibrations in the output layer(s) as well as the mechanical Q of the device to provide a low profile piezoelectric transformer with high power density. The preferably metal end-masses also act as high voltage output electrodes as well as heat sinks.

Abstract: A method for manufacturing a cofired multi-layer piezoelectric transformer device includes forming first and second green shapes of a sinterable ceramic composition and applying metallization layer therebetween. Upon cofiring, the composite structure comprises first and second electroactive members bonded together by a conductive layer therebetween. External electrodes are applied and the electroactive members are polarized in a thickness direction, between their two major faces. The first and second electroactive members are arranged such that deformation of one electroactive member results in corresponding deformation of the other electroactive member. The device provides substantial transformation ratios in which relatively high power may be transferred in relation to the size of the unit, operability over wide input and output frequency bandwidths, and electrical isolation of the input voltage and current from the output voltage and current.

Abstract: A composite structure is provided which resists corrosion and cracking due to water seepage and roadway use. The composite structure of reinforced concrete is wear resistant through bonding it to a liquid-impermeable overlay such as latex concrete with an adhesive imide. The imide has great adhesion to the concrete and has a thermal expansion and flexural strength comparable to the reinforced steel which prevents delamination of the imide and the overlay as road, bridge or deck roof is subjected to traffic and the elements.

Abstract: A small, lightweight, efficient, quiet electric shaver is provided in which one or more piezoelectric drivers are mechanically coupled to a cutting blade. The cutting action of the blade is generated by the piezoelectric drivers which, when electrically energized, oscillate at a predetermined frequency. The piezoelectric driver is electrically energized by a regenerative drive circuit. Hair shafts, which protrude from the surface to be shaved through a perforated foil member, are sheared at their base by the oscillating action of the blade.

Abstract: A method for manufacturing a multi-layer piezoelectric transducer having enhanced mechanical output displacement capability resulting from an increase in the amount of "pre-stress" applied to the electroactive (ceramic) layer by the pre-stress layer. The pre-stress layer is heated to a temperature above the temperature of the ceramic layer and bonded at an elevated temperature to the ceramic layer, such that, as the pre-stress layer subsequently cools down to ambient temperature, it applies a compressive stress to the ceramic layer. During the step of cooling the layers to ambient temperature, the temperature drop of the pre-stress layer is greater than the temperature drop of the ceramic layer, thereby increasing the amount of "pre-stress" applied to the electroactive (ceramic) layer by the pre-stress layer.

Abstract: A piezoelectric motor has a piezoelectric transducer disposed within a motor housing. The piezoelectric transducer is constructed of one or more piezoelectric elements, the opposite ends of which are loosely secured within recesses in the interior walls of the motor housing. Electric contact plates disposed on opposite major surfaces of each piezoelectric element hold the center portions of the piezoelectric elements in fixed relationship to each other and provide a means of conducting electical energy to the respective faces of the piezoelectric elements. A moveable piston member is attached to one of the contact plates. When an alternating voltage potential is applied across the major surfaces of the piezoelectric elements, the center portions of each of the piezoelectric elements, as well as the piston attached thereto, reciprocates within the motor housing while the ends of each of the piezoelectric elements remain secured within the recesses in the interior walls of the housing.

Abstract: A contact device for securely and reliably attaching electrical leads to a laminated multi-layer piezoelectric transformer and comprising a pair of conductive lead attachment plates, disposed on opposite sides of the laminated multi-layer piezoelectric transformer, each having first and second surfaces, the first surface having at least one leg extending therefrom to contact the laminated multi-layer piezoelectric transformer at a node and the second surface being sufficient to permit secure and durable attachment of electrical leads thereto. A variety of geometric configurations of the contact device of the present invention suitable or adaptable to a variety of laminated multi-layer piezoelectric transformer geometries are also described. Such a device, useful for the attachment of a laminated multi-layer piezoelectric transformer to a circuit board, is also described.

Abstract: An adhesive viscous liquid screed for dispensing a uniform thickness of an initially viscous liquid material onto a planar work surface in order to produce a film of predetermined thickness, length and width. The screed engages a planar horizontal application surface and a reservoir is filled with a liquid adhesive. As the screed is propelled forward along the application surface, the pressure on the adhesive due to gravity causes it to be forced out of the reservoir and through a first release orifice, thereby depositing a thin film of liquid adhesive. The height of the film is determined by the distance between the application surface and the bottom surface of a rib defining the release orifice and the width of the film is determined by the distance between the substantially vertical sides of the first release orifice.

Abstract: Circuits for use in ignition systems are disclosed which use a resonating piezoelectric transformer along with complementary circuit components, to efficiently convert a DC first voltage to a transformer-output AC second voltage. In the preferred embodiment of the invention, a High Displacement Piezoelectric (HDP) transformer converts a DC voltage into an AC voltage which is rectified into a DC signal of sufficiently high voltage to create a spark across the spark gap of a spark plug. The transformer circuit may be a "self resonating" circuit which relies on an initial pulse from turning on the DC power supply to cause the transformer to begin resonating. In a modified circuit the circuit is not "self resonating" and instead has a phase shift oscillator sub-circuit that provides small pulse signals to start the transformer resonating when the circuit is initially turned on.

Abstract: DC-AC voltage transformation circuits are provided which use a resonating piezoelectric transformer along with complementary circuit components, to efficiently convert a DC first voltage to a transformer-output AC second voltage. In the preferred embodiment of the invention, A High Displacement Piezoelectric (HDP) transformer achieves sufficiently high voltage output to "cold fire" a gas discharge lamp. The disclosed circuit may be modified using conventional electrical sub-circuitry to pre-heat the cathodes of the lamp. The transformer circuit may be a "self resonating" circuit which relies on an initial pulse from turning on the DC power supply to cause the transformer to begin resonating. In a modified voltage converter circuit, the circuit is not "self resonating" and instead has a phase shift oscillator sub-circuit that provides small pulse signals to start the transformer resonating when the circuit is initially turned on.