Abstract: An article of performance enhancing footwear having a piezoelectric spring apparatus in the sole member. Walking or running applies a first force deforming a piezoelectric actuator, thereby generating electrical energy. An energy storage circuit stores electrical energy generated by the piezoelectric actuator. Sensing means is provided to sense the release of a second force greater than the first force, which triggers the release of stored electrical energy back into the piezoelectric actuator. The resulting deformation of the piezoelectric actuator imparts a force into the bottom contact surface of the sole member.

Abstract: A ground fault interrupter circuit ("GFIC") device having as a switching device a flextensional electroactive transducer which, when energized, opens a supply conductor between a current source and a load. When a fault current is detected a voltage is induced in a coil; due to the condition that there is less current running through the conductor from the load than through the conductor from the power supply which both extend through the core of the coil. The voltage induced in the coil is amplified by a transistor which causes the transducer to piezoelectrically "snap" from a first neutral position to a second neutral position thereby cutting of current from the power supply to the load.

Abstract: A method for manufacturing pre-stressed piezoelectric actuators using a pre-curved piece of ceramic is provided. An adhesive, preferably a polyimide, is disposed between a metal pre-stress metal layer and a pre-curved PZT ceramic. The entire composite structure is heated to a temperature above the melting point of the adhesive material and then subsequently cooled to allow the adhesive layer to set. As a result of the difference in thermal contraction rates of the materials, the pre-curved PZT ceramic is compressively stressed. This pre-stressing provides a piezoelectric actuator which is durable, and produces a higher displacement than a conventional piezoelectric actuator.

Abstract: A vibrating hand trowel for finishing plastic concrete. The vibratory mechanism includes piezoelectric elements which vibrate at a high frequency when a voltage is applied to them. The trowel as a whole includes a top piece including a cover plate and handle, and a bottom piece including the piezoelectric elements mounted on a rib and a flat bottom which contacts the concrete. The top and bottom piece are preferably attached by a series of screws. The vibrating trowel is pulled over the concrete creating a smooth, wet layer useful for lubrication of the area where the trowel and concrete are in contact. This layer develops because the vibrations cause water and air to rise to the top of the concrete. The invention will allow for easy finishing of plastic concrete because of its lightweight and simple design. The invention will also create a smooth finish of the hardened concrete.

Abstract: A multi-layer piezoelectric transformer device includes first and second electroactive members having electrodes bonded to each of their opposing major faces; and a bonding layer disposed therebetween. The first and second electroactive members are polarized in a thickness direction, between their two major faces, such that when energized by an electric field the first and second electroactive members longitudinally strain. 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 voltage and current at the input to the device from the voltage and current at the output of the device.

Abstract: A piezoelectric snap-actuator includes a piezoelectric bender element with electrodes disposed on each major face, a spring member for causing the device to snap from a first neutral position to a second neutral position, a prestress layer for applying a compressive force to the piezoelectric bender element, and adhesive layers is provided. The piezoelectric bender element and the spring member are each bonded to the opposite faces of the prestress layer by an adhesive layer. The device assumes one of two neutral positions when not electrically energized. Due to the direction of poling of the piezoelectric bender element, when the piezoelectric bender element is electrically energized it strains in a longitudinal direction. This strain causes the device to deform. When the electrical energy is turned off, the device returns to one of the two neutral positions.

Abstract: A piezoelectrically actuated fluid pump including a pump housing, a pump chamber, inlet and outlet ports for communicating the pump chamber with the exterior of the pump housing, valves for opening and closing the ports, two prestressed piezoelectric diaphragm members which are self-actuated, and a power source is provided. The diaphragm members include a prestressed piezoelectric element which is durable, inexpensive and lightweight as compared with prior diaphragm pumps of comparable discharge capacity, and is actuated via electrical signals from an outside power source. No exterior mechanical parts for driving the diaphragm members are necessary. A modification is disclosed in which a central computer independently controls the phase angle of oscillation of the two diaphragm members, providing precise flow rate control.

Abstract: Vibrational energy is introduced into a portion of a liquid-solid work mixture at a natural resonant frequency of that portion of the mixture while that portion of the mixture is in a fluid or semi-fluid state. A vibrating apparatus imparts controlled vibrations either onto the surface or beneath the surface of the liquid-solid work mixture in sequential stages, the frequency of vibrations generally increasing with each subsequent stage, corresponding to an increase in the natural resonant frequency of the progressively-narrowing liquid portion at the top of the liquid-solid work mixture. A resonant frequency-indicative condition of the liquid portion of the work mixture adjacent the vibrator apparatus is sensed as the vibrator apparatus moves across the top surface of the liquid-solid mixture, and the output frequency of the vibrating apparatus is correspondingly adjusted in accordance with the sensed condition as the vibrator apparatus travels.

Abstract: A multi-segmented flextensional transducer includes a plurality of electroplated electroactive members which deform in concert when energized by an electrical field. Each electroactive member has a convex surface at one end and a concave surface at its opposite end. The electroactive members are arranged end-to-end such that the convex face of each intermediate electroactive member engages the concave face of an adjacent electroactive member, thus forming a cooperative array or "train" of electroactive members. The opposite ends of the train of -electroactive members is received by a frame which holds the end electroactive members in fixed relative position. The electroactive members are high deformation flextensional piezoelectric elements. When energized, each electroactive member individually deforms, and the entire array deforms in concert an amount significantly exceeding that of the individual electroactive members.

Abstract: A method for focussing vibrational energy upon a target volume within a surrounding contiguous medium imparts high intensity energy upon the target volume from low level energy sources. A plurality of standing compression waves are established within the medium along corresponding longitudinal axes between opposing pairs of coordinated transducers. The target volume is located at the common intersection of the axes of the standing compression waves. Opposing pairs of transducers are positioned from each other at a distance equal to an integer multiple of half wavelengths of the corresponding standing wave therebetween. The phase angle of each standing compression wave is regulated so as to cause each wave to be at its maximum intensity (amplitude) within the target volume at the point of common intersection with the other standing waves.

Abstract: An apparatus for focussing vibrational energy upon a target volume within a surrounding contiguous medium imparts high intensity energy upon the target volume from low level energy sources. A plurality of standing compression waves are established within the medium along corresponding longitudinal axes between opposing pairs of coordinated transducers. The target volume is located at the common intersection of the axes of the standing compression waves. Opposing pairs of transducers are positioned from each other at a distance equal to an integer multiple of half wavelengths of the corresponding standing wave therebetween. The phase angle of each standing compression wave is regulated so as to cause each wave to be at its maximum intensity (amplitude) within the target volume at the point of common intersection with the other standing waves.

Abstract: Vibrational energy introduced into plastic concrete structures, such as concrete slabs, decks and similar or related concrete structures, at or near the natural resonant frequency of the liquid concrete mass, expedites the consolidation and setting of the concrete. A vibrating apparatus imparts controlled vibrations either onto the surface or beneath the surface of the concrete mass in sequential stages, the frequency of vibrations generally increasing with each subsequent stage, corresponding to the increase in the natural resonant frequency of the progressively-narrowing liquid concrete at the top of the structure. The relatively more consolidated and more dry concrete (typically near the bottom of the slab) is substantially unaffected by the non-resonant frequencies vibrations. In one modification, sensors determine the resonant frequency of the liquid concrete mass during each pass of the vibrator apparatus, and the frequency of the vibrating member is automatically adjusted, accordingly.

Abstract: Therapeutic furniture for disabled persons adapted to support man and woman partners engaged in intercourse has longitudinally moveable man's seat facing adjustable-position female seat. Male partner is supported by seat with his back in a substantially upright position to relieve stresses on lumbar vertebrae, pelvis and legs. Longitudinal movement of the man's seat is effected by hand operation of a joy stick in mechanical communication with the seat, or, according to a modification of the invention, by actuation of an electric motor in electrical communication with the man's seat. Woman's seat and back are independently adjustable.

Abstract: An apparatus and method of sterilizing contaminated material by exposure to steam inside of substantially cylindrical, vertically oriented autoclave vessel. Contaminated material is shredded and bulk loaded from above autoclave vessel, directly into cylindrical wire mesh basket inside of vessel. Basket capacity exceeds 80% of volume of vessel. Path of thermal conductivity through contaminated material is reduced by inner sleeve along axis of basket. After completion of sterilization, top of autoclave vessel is opened, and basket containing sterilized material is removed by hoist positioned above the vessel.

Abstract: Pipe closure device with opposing dual mandrels has external conical surfaces which cooperate with internal conical surfaces of segmented rigid wall engagement member. Rotation of threaded shaft causes relative axial movement of dual mandrels and effects outward radial motion of rigid wall engagement members and outward motion of elastomeric seal, securing device to wall of pipe and sealing pipe closed. Rotation of shaft in opposite direction releases elastomeric seal and rigid wall engagement members from pipe wall. Inflatable seal seals against inside wall of pipe when inflated. Shaft is rotated by air-powered motor which is insertable and attachable into sealed receiver without use of tools.

Abstract: Broadcasting system digitizes audio input signals before RF modulating and transmitting over airwaves to one or more remote receiving stations. Receiving station recovers the digitized signal by demodulating and exponentially expanding the received RF signal. Recovered digital signal is subsequently frequency modulated and sent, via an electrically conductive cable, to an FM radio, over which the original audio input signals are faithfully reproduced. A time switch in series with the RF receiver and the FM modulator is capable of temporarily disabling modulated transmissions to radio through the electrically conductive cable. Relay stations, (either land-based or satellite), allow for transmission beyond the range (i.e. "line-of-sight") of common FM radio transmissions.

Abstract: Therapeutic furniture for disabled persons adapted to support man and woman partners engaged in intercourse has longitudinally moveable man's seat facing adjustable-position female seat. Male partner is supported by seat with his back in a substantially upright position to relieve stresses on lumbar vertebrae, pelvis and legs. Longitudinal movement of the man's seat is effected by hand operation of a joy stick in mechanical communication with the seat, or, according to a modification of the invention, by actuation of an electric motor in electrical communication with the man's seat. Woman's seat and back are independently adjustable.