Abstract: An elastic joint mounting and rotatably coupling a rotary inertial energy storage device or flywheel, to a shaft, the present gimbal structure reduces vibration and shock while allowing precession of the flywheel without the need for external gimbal mounts. The present elastic joint usually takes the form of an annular elastic member either integrally formed into the flywheel as a centermost segment thereof or attached to the flywheel or flywheel hub member at the center thereof, the rotary shaft then being mounted centrally to the elastic member.

Abstract: Biofouling is removed from the external surfaces of spaced apart pipes of a heat exchanger which are in contact with a liquid by positioning a plurality of ultrasonic transducers between the pipes and operating the transducers at sufficient power levels to cause cavitation within the liquid to effect the desired cleaning action. The transducers are arranged in a planar configuration to produce bi-directional acoustic radiation. Various types of instrumentation are provided for determining extent of biofouling and effectiveness of cleaning as well as for monitoring transducer operating parameters.

Abstract: The present invention relates to a method and apparatus for detecting the earth's static electric field and determining the contour of its equipotential lines and surfaces and for utilizing the detected field as a reference for other measurements. In particular, the contour of the field can be determined by sensing the potential at a plurality of points and measuring the differences in potential at the points with a differential static amplifier. Alternatively, a fluxmeter for measuring the electric field vector directly can be used to sense changes in the magnitude and direction of the field. A line defined between two points or a plane defined by three noncolinear points in space can be made to coincide with an equipotential line or surface in space, respectively, by adjusting the relative positions of the points such that either the potential differences between the points or the field components sensed along the defined line or in the defined plane are zero.

Abstract: The invention relates to a method and apparatus for providing pilots of aircraft or the like with: information about the presence, identification and relative location of, and time to potential collision with, other aircraft, objects, and obstructions, i.e. pilot warning indicator (PWI); instructions enabling pilots to avoid collisions, i.e. a collision avoidance system (CAS); and, advisory messages such as altitude and heading changes. The information, instructions and messages are organized, in accordance with the invention, through the use of a novel program subroutine in a general-purpose digital computer serving as a central communications computer or a specially programmed computer dedicated to controlling the encoding and transmission of digital air traffic control messages to pilot and/or controller information display terminals.

Abstract: Pulsed light and readily measurable pulsed electrical energy are independently applied to a solid black, conductive sample in a gas-filled photoacoustic cell, each causing the black sample to heat. The heating of the black sample causes a pressure wave in the cell, which can be detected and measured. By adjusting the pulsed electrical energy, the pressure wave resulting from the pulsed electrical energy can be made to relate to the pressure wave resulting from the pulsed light in a predetermined manner. The pulsed light input intensity can then be measured in electrical units based on the measurable input of the electrical energy pulses. In this manner, the invention can be used as a radiometer. A second application for the present apparatus is in calibrating photoacoustic spectroscopy (PAS) cells. The PAS cell can be self-calibrated by discontinuing the light pulses and relating the pressure wave output to the electrical energy pulse input.

Abstract: The present invention relates generally to the utilization of laser interferometry for performing detection of buried structures such as underground natural gas pipeline. More specifically, the invention relates to the use of a laser interferometer system for detecting leaks and similar defects, such as corrosion, in buried pipelines, pressurized containers or other metallic structures, based upon the sensing of subnanometer earth surface displacements produced by elastic waves which are emanated from the leak or defect and propagate in the surrounding earth medium.

Abstract: The present invention relates to a sensing device having a chamber containing positive and negative ions, wherein a fluid flow is directed into the chamber and ionized. The ionized flow passes between a plurality of conductive plates, the outputs from which can be used to indicate physical effects, such as air or gas flow and angular motion.

Abstract: A valve spool characterized by significantly lower flow induced axial force, the force being sufficiently low to render single stage servomechanical valves practical for small and moderately powered servomechanical apparatus. The present valve spool and servomechanical apparatus has a zero force metering edge which results from selection of a slope for the exit portion of the flow contour which is between that of a prior art rectangular port and that of the shallow slope typical of large negative axial force design. The present valve spool is further configured to allow metering across a small portion of the spool circumference in order to increase valve stroke and to minimize spool leakage. Preferably, a wedge is cut on two of the metering spool edges by grinding symmetrical flats across the valve spool edge to form the metering edges, the metering orifice then being defined by the intersection of the insert edge and the valve spool flat.

Abstract: Tissue stimulation apparatus for positive positioning of an electrode-bearing lead proximous to tissue which is to be stimulated electrically, the invention particularly includes a body penetration and insertion assembly which carries an elongated flexible strip of physiologically inert plastic material having at least one electrode positioned thereon into contacting relation with said tissue. The insertion assembly comprises a hollow needle having a slot formed longitudinally along the length of one wall thereof, the slot allowing transverse removal of the flexible lead from the needle after proper positioning of the lead and after removal of the needle from the body. The present slotted assembly allows use of a flexible electrode lead having electrical connections at the external end thereof which are too large to pass through the hollow needle.

Abstract: The invention relates generally to measuring the air speed of an object moving within the earth's atmosphere. In particular, the invention provides apparatus which comprises means for causing an air flow to enter an electric E field chamber, proportional to air speed, a portion of the air in the air flow being ionized prior to entry into the E field. Air speed is measured by the current resulting from charge separation in the field.

Abstract: The invention generally provides an improved, implantable electrode structure for human tissue stimulation application, and particularly proposes the use of pyrolytic carbon as material from which to fabricate the stimulation electrode. For cardiac stimulation use, the proposed electrode structure can be either a bipolar or unipolar unit, wherein the distal, tip electrode is made of pyrolytic carbon and the proximal or indifferent electrode is metallic. For other tissue stimulation applications, e.g., involving the cerebellar region of the brain, the proposed electrode structure is formed of a pyrolytic carbon electrode surrounded by an outer ring electrode formed of metallic segments; the electrodes being carried on the surface of a pad of cushioning material, such as foam silicon rubber.

Abstract: The invention relates to interrogation, detection, and monitoring apparatus useful for monitoring changes in the resonant frequency of a passive L-C circuit implanted in the cranium, the resonant frequency of the implanted circuit varying in a predetermined fashion with changes in the intracranial pressure. The present invention is disposed externally of the skull and provides apparatus for imposing electro-magnetic radiation on the implanted circuit, the frequency at which the radiation is absorbed being then detected and converted into an indication of intracranial pressure.

Abstract: The present invention relates to an apparatus and method for detecting and correcting burst errors of indeterminate length occurring in data entered along a magnetic tape or other storage medium. An encoder and decoder arrangement is provided wherein parity or check bytes are encoded and decoded across data blocks which are measured along and across the tracks of the storage medium and wherein the parity or check bytes are read onto separate tracks of the storage medium. The present invention provides for the continuous encoding and decoding of data because the parity bytes and data bytes are conveyed to and from the storage medium along separate tracks.

Abstract: An implanted tissue stimulator apparatus includes circuitry, powered by an implanted rechargeable battery, to produce electrical stimulation and apply it to selected body tissue. The condition of the rechargeable battery is monitored continuously and if the cell fails or its voltage drops below a preselected level, the stimulator reverts to a stand-by power source provided by a battery having an extremely long shelf-life. A back-up pulse generator is also provided and the control logic circuitry within the implanted stimulator monitors the operation of the pulse generator, in addition to the condition of the rechargeable battery, and if faulty operation of the pulse generator is detected the logic circuitry automatically switches to the back-up pulse generator in order to maintain adequate tissue stimulation.

Abstract: A method and apparatus for utilizing the earth's static electric field as a reference for generating an information-bearing electrical signal. In a particular embodiment, the invention provides a differential static voltmeter having spaced voltage sensing probes and a differential static amplifier which determines the difference in voltage sensed by the probes. Since the probes measure the static voltage which occurs as a vertically oriented gradient in the earth's atmosphere, the voltage difference signal produced by the differential static amplifier is a measure of the disposition of the probes relative to a line usually parallel to the earth's surface, the voltmeter thereby being particularly useful as a pitch and roll stabilization reference and control system for airborne vehicles. In other embodiments, the invention also provides apparatus for defining a horizontal reference plane in the atmosphere and apparatus for sensing the roll or pitch rate of an airborne vehicle.

Abstract: A recording/reproducing system for radar and similar type data is provided wherein all data necessary to record and later reproduce an accurate data (radar) display is formatted on a single recording track; e.g., on magnetic tape, in the form of a single composite signal. In one embodiment, the composite signal contains radar video and trigger markers and is chopped by a multi-bit, bi-phase data signal containing word synchronization sequence, trigger identification, radar coordinate information, and any other pertinent data, as desired. In a second embodiment, the radar video and trigger markers frequency modulate one carrier signal, which is then combined with a second carrier which has been frequency modulated with data (i.e., word synchronization, trigger identification, coordinate information, etc.) to form the composite signal.

Abstract: Pressure monitoring apparatus implantable in the cranium to measure intracranial pressure, the apparatus comprises a passive resonant circuit having a natural frequency influenced by ambient pressure. The resonant circuit has inductance and capacitance capability for comparing the local environmental pressure to that of a volume of gas trapped inside the apparatus, the environmental pressure being measured by observation of the frequency at which energy is absorbed from an imposed magnetic field located externally of the cranium.

Abstract: The invention generally relates to inertial energy storage devices formed of wound anisotropic material. In particular, the invention provides a disc-like flywheel formed of windings of anisotropic filaments wherein the filaments are provided with a relatively thin sheath of flexible material around each of the filaments, the flexible sheath providing positive contact between adjacent windings even during deformation of the windings caused by rotation of the structure.

Abstract: The invention relates to rotary inertial energy storage devices comprised of wound filaments or discrete rings of essentially anisotropic material formed into a rim or disc-like configuration. Pairs of adjacent rings or windings in any given plane perpendicular to the axis of rotation of the present structure are tied or bonded together at discrete peripheral points at selected locations while adjacent rings which are not bound at these first-mentioned tie points are tied together at other peripheral points interdigitated between said first-mentioned tie points. These points of connection extend linearly throughout the structure.

Abstract: The invention relates to inertial energy storage devices comprised of anisotropic filamentary elements and comprises several embodiments of a disc flywheel which, although consisting essentially of anisotropic elements, is effectively isotropic in total structural character. A preferred embodiment of the invention is generally formed by weaving anisotropic filamentary elements together at regular angles to each other, certain of the woven anisotropic elements being parallel to each other to form essentially unidirectional layers within each woven disc-like unit. The woven disc-like units thus formed are bonded together to form a structure of useable size, the units being either randomly oriented relative to each other or oriented at regular angles to each other.