Abstract: A compensator for use with a hydraulic control valve connected to a source of high fluid pressure provides the functions of a low pressure return line accumulator and controllable check valve. A spring loaded piston (66) in a housing (64) has a working face exposed to fluid pressure downstream of the power control unit (10). A poppet valve (80) movable in a bore (78) on the axis of the piston is spring loaded against a seat (82) in the return line (40, 42) to interrupt flow between the downstream side of the power control unit (10) and the return side of the fluid pressure source. When normal return line pressure is sensed, the piston (66) moves against its spring (68) to permit the housing (64) to be substantially filled with fluid. Further increases in fluid pressure cause the piston (66) to contact and open the poppet (80) and permit flow to the return side (42) of the fluid pressure source.

Abstract: An underwater connector for electrically and mechanically connecting elongated sections of a towed sonar array and the like includes male and female connector sections terminating array sections, each connector section including a lightweight bulkhead member sealed thereto, one of said bulkhead members including a pair of miniature check valves which are oppositely directed and the other including a fill port for filling the array section to which it is attached with a suitable acoustic liquid. Each of said bulkhead members includes a central aperture supporting one half of an electrical connector. Axially displaced from each bulkhead member in each connector section is a strength member support to which is attached a plurality of high strength ropes which carry the tensile load on the array. These strength member supports are fastened against the force from the ropes by means of retaining rings.

Abstract: This invention utilizes data collected in the course of reflection seismic prospecting methods to produce a map, such as a vertical profile or a three-dimensional picture, of subterranean earth formations. This is accomplished by aplanatic mapping of received seismic wave trains in the memory unit of a computer taking into account the travel times of waves, the location of the source, the location of the receiver, and the velocity with which the waves travel from the source point to the deflecting point in the earth and from then to the receiver. The data recorded by each source receiver doublet is digitalized and stored aplanatically in the memory unit, taking into account both signs and amplitudes of the signals. The accumulated data represents a map of the earth formations. Sections of this map are plotted to provide desired views of the formations.

Abstract: This invention is concerned with systems for converting seismic waves received at various points at the surface of the earth into digital signals and the transmission of those digital signals from the geophone stations to a recording truck. Address registers located at the geophones are employed to permit periodic selective interrogation of the individual geophones. Typically, electric signals generated in the geophones, such as digital seismic signals, are time-multiplexed for return to a recorder over a common cable.

Abstract: A rotary valve of generally cylindrical configuration is arranged to drive two piston-type hydraulic motors by distributing fluid under pressure and return pressures to and from a series of motor ports which match the inlet ports of the motors. Fluid at inlet pressure and at return pressure is distributed through a series of axial passageways to a number of distribution ports. The distribution ports, which would be extremely complex to fabricate with usual casting or machining techniques, are formed of a number of series of stacked disks whose output or input openings are controlled by a rotary member having radial openings and axial passageways. The disks are formed with a symmetrical pattern of ports such that when flow is initiated from a given opening an oppositely disposed opening also will initiate flow, thus radially balancing the forces.

Abstract: A structure for connecting together separate elongated small diameter sonar arrays and nonacoustic modules includes a pair of cylindrical housings which telescope together with a keyway to prevent radial movement and each of which includes means for anchoring a plurality of strength members in the form of ropes of aramid fiber. The outside one of the two telescoping housings includes external threads and an external groove for retaining a seal. The inside cylindrical housing includes two external seals, one of which is in contact with the other housing, and an external groove and shoulder. A sleeve member surrounds the telescoping housing members and includes an internal surface in contact with the other two seals, internal threads engaged with the external threads, and a shallow internal groove carrying a radially expanding retaining ring which, in operation, wedges into the shoulder and against the sleeve to transfer the load from housing to housing.

Abstract: A digital homodyne processing system is disclosed and includes a hydrophone, a preamplifier for amplifying the hydrophone output signal, a heterodyne circuit and a low-pass filter for filtering the amplified hydrophone output, and a digital-to-analog converter. The output of the digital-to-analog converter is compared against sine and cosine references and is integrated as a function of the sine and cosine references. The integration results are processed for detection of a coded waveform.

Abstract: A system for providing signals to a microprocesser-based control from which instantaneous values of speed can be computed includes a wheel-driven alternator which provides an alternating current output whose frequency varies with wheel speed. A signal processor converts this signal to a series of sensor pulses whose width varies inversely with frequency. A sample pulse is supplied from the microprocessor which sets the period or length of time the sensor pulses are examined for each speed calculation of the microprocessor. The sample period pulses are AND gated with a high rate clock and also with the sensor pulses to provide a series of marker pulses marking the up and down excursions of the sensor pulses.

Abstract: A doser type hydraulic actuator includes a pair of unequal area pistons on a common shaft which are moved incrementally by injecting into or removing from a control pressure chamber metered quantities or doses of fluid. Doses are metered by timed openings of solenoid valves connecting the control pressure chamber to supply or return pressure sources. Special valve means are provided for moving the actuator piston to a preferred position in the event of control system failure, and means are included for administering very small doses consistently without recourse to special extra fast response solenoid valves.

Abstract: A flexible shaft is formed of a plurality of linked sections which lock together to provide a rigid shaft when turned in a first direction as for drilling and which, when turned in the opposite direction, unlatch, thereby permitting limited relative movement of the sections so that they may follow a curved path for storage. As the sections are rotated in the first direction, certain internal notches of one section and mating external projections of the next section tend to wedge together and then do not always separate easily and readily when the torque on the shaft is reversed.

Abstract: A construction for an electrical cable which carries an underwater transducer and is repeatedly reeled onto and from a hoist in a helicopter into the ocean to substantial depths. The cable includes a coaxial construction of copper conducting wires including a center conductor wound in a helix angle around a nylon center rod with the wires covered with a significant layer of polypropylene insulation and a tubular construction of fine copper wires wrapped around the polypropylene insulation in a helix angle and, in turn, wrapped with a copper-mylar tape with the copper layer adjacent the conducting wires. The tape is covered with a layer of polyvinylchloride insulation covered with an open-weave light Dacron braid bedding layer. The bedding layer serves to distribute forces from the armor layers which consist of a first layer of steel wires wound in a helix angle smaller than that of the conducting wires and in the opposite direction.

Abstract: A molded plastic carton end includes a thin face panel reinforced by molded ribs and bounded on four sides by rim sections each comprising a plurality of parallel walls abutting against a face member with closely spaced cross members to add additional stiffness and resistance to crushing. The multiple walls also provide a plurality of parallel layers to receive and hold nails for attaching side, top and bottom members to complete the carton. The walls intersect at the corners, thus forming a large number of individual box sections at each corner, making the corners of the carton end very resistant to deformation. A number of plastic materials and fillers may be used including polyethylene filled with wood and/or a limited amount of a blowing agent.

Abstract: A system for counting fish in a body of water uses one or more acoustic focusing liquid lens transducers each of which includes a large number of individual piezoelectric elements arranged in an arc to create a fan-shaped pattern of adjacent beams, each of which has a narrow beam width. An electrical counting circuit includes a clock producing a series of timing pulses supplied to a plurality of binary coded decimal (BCD) actuated switch circuits, one of which initiates sequential operation of transmit pulses from individual transducer elements. Timing of receiver operation is also controlled by said timing pulses after a delay to minimize "ringing" of the transducer elements from the transmit pulses. Received echo signals are amplified, threshold detected and converted to uniform pulses.

Abstract: A sonar array consists of a significant number of interconnected disk-shaped transducer projectors operating in the bending mode and packaged in a cylindrical housing including a first or lower section including an electronics and battery package for powering the transducer projectors; a main housing containing the stacked, interconnected transducer elements and having padding of foam material for protecting the transducer elements during deployment and handling; and a rear case section which contains a parachute to control rate and attitude of descent from the launching aircraft, a float or buoy in association with the parachute for providing flotation during operation, and a coiled length of nylon rope for suspending the deployed array at the desired distance below the surface. A retaining line or spring clips are used to hold the transducer elements in the main case section during descent in the water following separation of the rear case section and uncoiling of the nylon rope.

Abstract: A closed loop idle speed controller for a fuel injection system operates to control an air valve which controls an air passage bypassing the main air flow. The air valve is positioned by an actuator whose output position is controlled by fuel pressure operating against a spring. The fuel pressure is controlled by a pair of solenoid-operated on-off valves, one of which responds to electrical signals representing engine speeds below a speed reference to direct fuel to the actuator and the other of which responds to signals representing speeds above the reference to permit fuel to be withdrawn from the actuator and returned to its source. Each of the solenoid on-off valves is supplied from a pulse width modulator. The engine-driven distributor provides pulses responsive to engine speed which are connected to a sample and hold circuit. The sample and hold circuit provides d.c.

Abstract: A termination and method of terminating braided ropes or cables of aramid fiber includes fabricating short tapered reinforcement ropes of the same material which are inserted at each end of each rope to increase its thickness, forming a collar having a tapered interior channel and a tube to fit inside the channel having a tapered outside surface. The reinforced rope ends (four, in this example) are tied off near their ends, separated into individual fibers, and any coating thereon washed out. These ends are then dipped into a suitable resin potting compound. A centering tool is inserted through the bore of the tube and used to pull the tube tightly into the interior of the collar, thereby compressing the ropes including the resin-coated ends tightly between the collar and the tube. The resin is then cured. Where it is desired to terminate both ends, the ropes initially terminated are doubled to leave loops at the opposite end.

Abstract: Life extending means for a typical spool type servo valve consists of a stack of washer-like disks which cooperate to define a number of finely divided flow paths across the stack in which initial flow, as the spool valve is opened, is forced through alternating chambers and orifices with measured pressure drops across the orifices and wherein subsequent increments of valve travel expose large openings providing flow rates versus travel comparable to conventional spool type valves.The individual disks may be made comparatively thin such that the thickness of two or more disks is required to provide a normal opening width into the stack. Thus a first disk and a second disk may have openings registering at identical positions to admit flow into the stack as a spool valve land passes the disks.

Abstract: An electrical fuel injection system incorporates electromagnetic injectors wired in two groups and which are operated on alternate cycles during low speed and normal operation. With increasing power demands, the fuel injection computer supplies pulses of increasing length to keep the injectors open longer and supply more fuel to the engine. Two trains of timing pulses are initiated by reed switches operated by the distributor, and each is connected to a pair of latch circuits operative to provide timing pulses on one channel through gate devices to one set of injectors and to block pulses on a second channel to the other set of injectors. The subsequent signal from the other reed switch results in a timing pulse in the second channel. These timing pulses are supplied to the fuel injection computer to initiate the injection pulses and to AND gates which also receive the timing pulses.

Abstract: A towed submersible body is utilized for housing underwater instrumentation, particularly a scanning type of sonar, the housing constituting a sphere which is attached at its top to a cable towed by a helicopter or by a surface vessel. The spherical housing of acoustically transparent material has hatches and ports top and bottom to aid in flooding and draining the interior. Ballast weights are fastened to the bottom of the housing near the lower hatch to control the location of the wet center of gravity of the body such that it is significantly below and slightly forward of the geometrical center of the sphere to provide stability during towing. A small projection on the housing in the form of a small diameter wire rope fastened to a meridian passing through the tow point or a point approximately 10.degree. aft of the tow point provides for stable towing at speeds up to approximately eight knots with the tow cable at an angle not more than about 10.degree. from the vertical.

Abstract: A drill drive mechanism is especially adapted to provide both rotational drive and axial feed for a drill of substantial diameter such as may be used for drilling holes for roof bolts in mine shafts. The drill shaft is made with a helical pattern of scroll-like projections on its surface for removal of cuttings. The drill drive mechanism includes a plurality of sprockets carrying two chains of drive links which are arranged to interlock around the drill shaft with each drive link having depressions which mate with the scroll-like projections. As the chain links move upwardly or downwardly the surfaces of the depressions in the links mate with the scroll projections to move the shaft axially. Tangs on the drive links mate with notch surfaces between scroll projections to provide a means for rotating the shaft. Projections on the drive links mate together at the center to hold the drive links tightly around the drill shaft.