Abstract: A variable area jet nozzle construction capable of blocking flow in favor another nozzle in a vertical or short take-off aircraft utilizes a balanced two-dimensional flap that is pivotable about rollers and movable, along curved tracks cooperable with the rollers, to assume a plurality of nozzle area varying or blocking positions under the influence of linear hydraulic actuators.

Abstract: An improved microphone assembly for use in a diver's mask or helmet and wh is characterized by a substantially flat frequency response at pressures from 1 to 30 or more atmospheres of breathing gas. A silicone rubber coated piezoelectric diaphragm is mounted by its periphery in a cylindrical housing with both sides of the diaphragm exposed to ambient gas pressures. A ground plate is mounted in said housing with one side in spaced relation to the diaphragm and having on the other side thereof a preamplifier and automatic gain control circuit electrically connected to the diaphragm and encased in waterproof potting compound.

Abstract: A portable pulsed signal generator which generates a low-frequency, high-ered signal from a constant direct current, low power source is disclosed as including an inverter for driving a plurality of motors which, in turn, actuate control switches by means of cams and cam followers associated therewith. A potentiometer driven by one of said motors, in turn, effectively controls the output of a direct current amplifier, with the varying direct current output signal therefrom having the alternate half-waves thereof polarity reversed by switch controlled relays, the switch of which is timely actuated by one of the aforesaid cams, cam followers, and other switches, respectively, so as to produce a low-frequency, high-power, substantially alternating current signal. After appropriate transduction said low-frequency, high-power, substantially alternating current signal may be employed for sweeping mines.

Abstract: An open circuit heat engine, utilizing air as the working fluid, is described wherein an intermittent flow heat exchanger recovers heat energy from spent air to add heat to air prior to expansion into the working chamber.

Abstract: A stabilizing drag and spin inducing device is described for an instrumen underwater vehicle. A flexible plastic disc having a central aperture and segmented into angularly offset vanes is pressed onto the vehicle probe section with resulting distortion causing the disc to assume a conical configuration. The vanes flex to increase drag on descent and decrease drag on ascent, while also assuming spin inducing pitch.

Abstract: A voice operated relay system is disclosed which includes signal processing ircuitry for receiving and discriminating with respect to human speech signals and for actuating a relay in response thereto. A power supply test is also included, as well as circuitry for preventing relay drop out due to input speech hesitations. The preferred embodiment of the subject system is disclosed as a means of enabling a cassette recorder and for causing it to record said human speech signals at either near or remote locations.

Abstract: An array of circular, acoustic projecting and receiving transducers is deibed, including a stainless steel baffle plate in which the transducers are mounted, each comprising a stainless steel cup containing a disc-shaped piezoelectric element set in low impedance material and covered by a water impedance matching window. Capacitive and inductive tuning means is provided between each receiving transducer and its associated electronics.

Abstract: A sonar system is disclosed which incorporates a first receiver for receig an acoustical signal from a target via a vertical path sector of water encompassing said target, a second receiver for receiving an acoustical signal from said target via a horizontal path sector of water also encompassing said target, and readouts for displaying the images of said target along with the physical characteristics of said vertical and horizontal water path sectors encompassing it. Selector switches are employed that enable an operator to select any one of a number of said vertical and horizontal water path sectors and to highlight them if desired, so as to optimize the target image as a result of selecting the water path sectors having the least signal resistance. Optionally, the subject sonar may be made active by including a target search signal broadcasting means, so the aforementioned received acoustical signals will be target echo rather than target source signals.

Abstract: Apparatus is described for remote VOR (voice operated relay) control of a pe recorder having a single control element, e.g., a push-button, for effecting both pause and run functions on alternate actuations. A function feedback signal conditions a logic network so that solenoid actuation of the push-button occurs only in response to appropriate VOR logic command signals.

Abstract: A spool wherein line pay out is limited to a selected length by a pin that s retractable from one or more loops previously formed in the line and extending through a spool flange opening. A detented thumb wheel is eccentrically connected to the pin for retraction thereof.

Abstract: An explosively powered tool or wrench is described that is operable under water and provides high torque, approaching that of an impact wrench, through the detonation of small charges to generate pressure for driving pistons of an expansible chamber motor. The invention is characterized by a rotating magazine for automatically or manually bringing charges into firing position, a magazine position indicator, and electrical firing control circuitry.

Abstract: A hydrodynamically streamlined, towable sonar apparatus is described charerized by a housing, including a central frame having a circular planar web portion from which extend a plurality of annular coaxial ribs which cooperate with similar ribs extending inwardly from top and bottom concavo-convex cover members to define annular chambers and to provide compressive load bearing support. Transducers are arrayed on the periphery of the frame and enclosed in a curved plastic fairing thereabout. Electronics are accommodated in the annular chambers.

Abstract: A manually operable self-loading trailer of wagon configuration is descri wherein tailgate ramps are operated by jacks to elevate rear end of trailer while rear carriage is moved adjacent front carriage, and then to lower rear end of bed to near ground. Jacks incorporated in carriages permit altering of bed height and attitude and aid in converting trailer to tandem axle semi-trailer.

Abstract: A conversion system is disclosed for generating a desired bandpass waveform rom digital samples of a lower frequency, bandlimited original waveform. The system utilizes a single digital to analog converter and an impulse driver to generate a weighted pulse train that contains frequency shifted replicas of the primary spectra of the original waveform. Bandpass filtering rejects all but selected replica spectra for reconstitution.

Abstract: A water wave height and fluid level measuring system is disclosed as having buoyant support mast which floats partially above water and partially below water in a substantially vertical disposition. A radio frequency transmitter is mounted on said mast above said water, and a plurality of radio frequency receivers are mounted on said mast at spatially disposed positions along said mast and submerged within said water. Telemetering, receiving data processing, and readout means are effectively connected to said receivers for communicating the output signals therefrom to predetermined remote or other locations, with said output signals being analog signals which represent water wave height or other fluid level at any given instant.

Abstract: A pulse-width doubler is disclosed as comprising a bistable multivibrator ving a first input, a second input, and an output, for producing a first signal at the output thereof in response to a predetermined second signal being supplied to the first input thereof and for producing a third signal that is different from said first signal at the output thereof in response to a predetermined fourth signal being supplied to the second input thereof.

Abstract: A cryogenic magnetic field gradiometer is described wherein adjustments of areas presented by a superconducting wire loop, that is confined in a support structure within a cryogenic environment, are adjusted mechanically through wire positioning elements operated by a plurality of parallel shafts extending to the exterior of the environment. In one embodiment the positioning elements are cams that cooperate to position portions of a wire loop, while in another form bell crank levers are used.

Abstract: A breech and latch mechanism is described herein for use in an aircraft mile ejection launching system. The described mechanism is characterized by a fluid actuated piston that rotates a bell crank and link from a hook locking over-center position to a hook retracting position. The piston acts also as a sequencing valve to pass fluid to pressure actuated ejection rams. A pressure fluid distributing orifice structure and a pyrotechnic cartridge igniting firing pin structure are described also.

Abstract: A diver's exhaust valve is described that is characterized by small size, ooth flow, and freedom from fouling by foreign matter. The valve comprises a valve member in the form of a spring and water biased diaphragm that separates the exhaust gas from the water which acts to close the valve. The disposition and configuration of flow passages produce continual flushing, while permitting adequate flow with a valve of smaller than usual size.

Abstract: A pitch synchronized helium speech unscrambler is disclosed as including a air of bucket brigade analog delay lines which are timely and rapidly loaded with the electrical signal equivalents of human voice signals that are effectively supplied thereto by a receiving transducer. Said voice signal equivalents are then respectively unloaded more slowly from said pair of bucket brigade delay lines than they were loaded therein by a pair of different frequency clock generators driven in alternate successions by preprogrammed signals divided out from a master oscillator and in synchronism with a predetermined pitch portion of the speech signal received by said receiving transducer. The unloaded signals are then broadcast as acoustical voice signals by a transmitting transducer.