Abstract: An apparatus for simulating the recoil motion of a weapon. The apparatus comprises a weapon having a trigger mechanism and an orifice located near the tip of the weapon. Whenever a trainee rifleman activates the trigger mechanism, timing means generates a trigger pulse. The trigger pulse, in turn, activates a two-way valve which allows a stream of compressed air to pass from a compressor to an intake port located on the weapon. The stream of compressed air is then passed through the orifice of the weapon so as to simulate the recoil motion of the weapon.

Abstract: In an unmanned underwater instrumentation vehicle, travel to an assigned th and cyclical excursions between depth tolerances above and below that depth are effected by a mechanism that alternatively drops vernier weights by firing explosive release bolts and floods buoyancy chambers by firing explosive piercing cartridges.

Abstract: Apparatus for determining the bearing of an acoustic source from a selected ocation in an acoustic environment includes a plurality of discrete acoustic sensor elements and a flexible member, having first and second ends, which may be deployed in a linear configuration in the environment. The sensor elements are attached along the flexible member in spaced apart relationship, one of the elements, comprising a lead element, being closer to the first end than any of the other elements. A motion measuring device is coupled to the lead element when the flexible member is deployed in the environment to generate signals which indicate the velocity of the lead sensor element in the environment.

Abstract: Transmission of wideband data through single-mode optical fibers is feasible due to far less dispersion. The appropriate index difference between the core and cladding and the dimensions of the core diameter are identified and selected to achieve minimum total dispersion at 1.55 .mu.m for single-mode step index fibers. A minimum total dispersion results from a cancellation between the material and waveguide dispersions which is owed to the proper selection of these parameters.

Abstract: A submarine's mast and its protective closure are prevented from inadvertly damaging each other while deploying or retrieving the mast and while securing the closure. Interconnected logic circuitry electronically prevents an improper actuation sequence so that the mast and closure do not collide. Mechanical linkages and fail-safes susceptible to corrosion and damage are eliminated thereby permitting more reliable operation from circuitry safely stowed inside the submarine.

Abstract: A coalescing/filtration media composed of yarn-like material held together during normal operation but loosened during backwash to allow "strumming" or vibrating to help loosen media-clogging material, and an armature arrangement by which a cylindrical assembly of yarn segments can be tightened in a helical fashion to perform as filtration/coalescing media or, during backwash, can be loosened to promote the dislodging of clogging material.

Abstract: In an underwater-mateable connector system of the vented pin-and-socket t, the socket electrical contact system is composed of a contact ring cooperating with a contact band, the contact band being integrally provided with a multiplicity of resiliently deformable louvers. The pin electrical contact is composed of a rigid conductor disposed intermediate electrically insulating material and is arranged to provide electrical contact with the deformable louvers of the contact band. Electrically insulating interference seals are formed on either side of the contact area when mated due to differential diameters between the pin and socket. The preferred embodiment utilizes a Multilam.RTM. band (U.S. Pat. No. 3,453,587) as the contact band.

Abstract: A display screen shows a number of alphanumeric characters in accordance with computer originating signals. These signals are fed to a liquid crystal panel which responsively vaires its opacity and, preferably, tapered fiber optics extend from one side of the liquid crystal panel to the screen. In one mode light originating from a high intensity source behind the screen is transmitted through the fiber optics. In another mode light from the front of the screen is reflected from a reflector surface behind the liquid crystal panel to the display screen. Either mode of operation allows the fabrication of a matrix of a number of liquid crystal panels and their associated fiber optics to provide an expanded display screen. Thus, an expanded visual presentation is read out from a computer or similar source of controlling signals to assure that several observers are reliably informed.

Abstract: Apparatus that imitates the appearance of a commercial deep fat fryer and simulates grease fires. A first burner extends into the bin of the fryer which would be occupied by cooking oil in the operational fryer, and a second burner occupies an area under the hood near the exhaust vent. Also included, out of sight, are a switch controlled by the lid on the bin, an extinguishment sensor in the bin, and a thermostat, which act together to disable the burners and deactivate the simulator when proper fire fighting procedures have been employed by the trainee.

Abstract: A compact, unitary sensor array support structure for use in a water medium omprises a plurality of scissor arms mounted on a support. The scissor arms are extended from the support to expand the sensor array, and are retracted to the support when the array is to be recovered. The support with the scissor arms retracted thereto is slidably housed within a container. Together, the support and the container form a hydrodynamic body which can be transported by towing in the water or removed from the water for transport or storage.

Abstract: The output of the vertical accelerometer of a ships inertial navigation sem (SINS), in pulse form, is first counted and scaled to provide an output related directly to the total acceleration. The SINS computer provides the latitude, and north and east velocities of the ship, which are then converted into the theoretical gravity and the Coriolis error. These two factors are subtracted from the total scaled acceleration, and the resultant output is passed through a filter that corresponds to a particular weighting function (heavily weighted for the middle time) to remove the factor of ships heave acceleration. The final output is the free-air gravity anomaly in terms of real time.

Abstract: A pressure sensitive line transducer wherein electrical signals are generd by the modulation of the electrical resistance of a coaxial cable due to pressure variations because of an impinging acoustic wave. The signals are extracted via a step-up transformer, amplified, filtered and processed by a computer and displayed to extract information about the acoustic wave.

Abstract: In a diver heating system of the type in which a fluid being circulated in he circulation passage of the diver's clothing is heated by the controlled combustion of a reducing metal in an oxygen atmosphere, a temperature control system in which a gas flow control valve controls the oxygen flow to the reaction to automatically maintain a preset temperature of the circulating fluid and a gas shut-off valve serves as a backup to quickly shut-off the oxygen flow if the temperature of the circulating fluid exceeds a preset value. In both the gas flow control valve and the gas shut-off valve, the heated water is fed through a heat exchanger where it is in thermal contact with a thermofluid so that heat is transferred between the two fluids. The change in volume of the thermofluid with temperature is coupled to a motion bellows which operates to control the flow of oxygen through an orifice.

Abstract: A linear acoustic array for use in oceanographic work in either a towed or a vertically suspended configuration utilizes a flexible cable in which strands are woven or braided into a tube, the strands of which can be separated sufficiently to insert a hydrophone and multiplexer assembly at each of a plurality of specified locations therealong. Each hydrophone and multiplexer assembly is adapted to be readily connected into or removed from a two wire system.

Abstract: A measured stream of particles is dropped onto the apex of a distributor e where it is divided into a circular pattern falling through a narrow sizing zone onto the peripheral edge of a rotatable platen. Platen rotation carries each particle into a frame area viewed, preferably, by a microscope and a TV camera the output of which is applied to a computer programmed to analyze selected characteristics. A rotatably-indexed mirror system reflects selected views into the microscope for the analysis. Interfaced with the computer is a signal generator providing feed-back signals that synchronously control system operation. For example, a feed-back signal stops platen rotation when a particle is brought into the viewing or frame area. Other signals control other functions such as the indexing of the mirror system to provide the desired views, i.e. front, back, top, bottom, etc. Scanning devices other than optics can be used if so desired.

Abstract: The guard retains the cable on a pulley of a cable control system that indes another pulley mounted on a pivotable radius arm for swingable movement relative to it. Usually, the swingable pulley is linked to a third pulley mounted on a hinged structural member which itself swings with the radius arm to and from `closed` or `open` positions. When the arc is wide, i.e. around 180.degree., conventionally mounted guards engage and bind the swinging cable. The present guard is an elongate member pivotally mounted on the radius arm. In the `closed` position, a retaining flange formed on the guard moves for cable retaining purposes into close proximity with the fixed pulley and the proximity or clearance can be adjustably fixed and locked by an eccentric stop. During the `opening` swing, the cable engages the guard which then pivots sufficiently to prevent the undesired binding. The pivotal range of the guard is restricted by a pin and slot arrangement.

Abstract: A power converter which provides precise waveshape regulation. An input pr waveform (three-phase or single phase power) is rectified and modulated to form a chopped waveform within an envelope defined by the rectified input waveform. The modulation is removed by passing the chopped signal through a low-pass filter. The output of the low-pass filter, which is equal to the instantaneous value of the chopped waveform envelope times the instantaneous value of the duty cycle of the chopped waveform, is converted to a complete sine wave output voltage in a power inverter. The output of the power inverter is sampled and compared with a low-power reference waveform in a differential amplifier. The output of the differential amplifier is phase compensated for the effects of the low-pass filter and applied as an error signal to a pulse-width-modulated oscillator to adjust the duty cycle of the chopped waveform so that the sine wave output voltage follows the reference waveform.

Abstract: An inductively coupled plasma torch (ICP) provides an efficient means for ermally degrading many organic molecules and exciting the resulting atomic species into optical emission. Spectrometric analysis produces reliable data for qualitative and quantiative simultaneous, multi-element analyses. To determine the empirical formula of a molecular compound, a gas chronometer is used to separate a mixture and atomic emission monitored continuously by a multi-channel spectrometer over the period of time required for the rise and fall of the elution. The plural channels provide parallel outputs defining intensity relationships or ratios of the excited elements. Instantaneous sampling repetitively made during the elution period provides a large number of discrete ratios that are averaged to provide the desired empirical formula. Molecular formulas then are derivable.

Abstract: The expander system is utilized for installation and removal of a rubber t over an underwater transducer. The installation system comprises a vacuum tank, adjusting sleeves, boot spreader and C clamps. The rubber boot is expanded at both ends by means of the boot spreader and then is expanded along its sidewall in a radial direction by means of a differential pressure created by pulling a vacuum on the outside surface of the rubber boot. The boot is then slipped on the transducer. For removal of the boot a short handled hook tool is used in place of the boot spreader. The method again includes pulling a vacuum on the outside surface of the rubber boot so the boot expands enabling the removal of the transducer.

Abstract: Microstrip antenna systems having two ground planes spaced apart by a dietric substrate and radiating elements coplanar with one of the two ground planes, or sandwiched within the dielectric substrate separating the two ground planes adjacent a window in one of the ground planes. The two ground planes are shorted together in most instances, and the dual ground plane system provides a reduction in the leakage losses of tranmission lines feeding and/or interconnecting the microstrip antenna radiating elements. The dual ground plane system also provides a reduction in coupling between arrayed radiation elements as well as an increase in bandwidth, in some instances.