Abstract: An open chamber gas powered tool and gas generating charge for the tool. The charge has a hollow open-ended plastic jacket of uniform noncircular cross-section from end to end containing a propellant, such as nitrocellulose, which may be electrically ignited through an open end of the jacket by a spark, hot wire or the like or ignited by detonation of a dab of priming compound contained within a recess in one end of the jacket. The tool has an open chamber breech mechanism including a cylinder containing a firing chamber opening through the cylinder circumference for transporting charges to firing position wherein the chamber is closed by the breech frame, a trigger actuated firing means for firing the charges in firing position, and operating means powered by the gas generated by each fired charge for performing a work function.

Abstract: A demodulator for a biphase or quadriphase shift-keying system. The demodulator includes two AND gates for biphase demodulation. The AND gate is one which will provide an output signal if and only if the two input signals are in phase. Each of the AND gates forms a feedback with an injection locked oscillator. Therefore depending on the phase of the input signal, one or the other AND gate provides an output which is then injected at the proper phase into the injection locked oscillator. The output of the AND gates is fed to a data logic and envelope detector to recover the data. For quadriphase phase-shift keying, four AND gates are required. The circuit can be constituted either by transistors or by transferred electron devices sometimes called Gunn effect devices.

Abstract: A system for transmitting digital information such as audio or video over a lossy or dispersive medium. The digital information is of the type where certain bits are more important than others and hence the less important bits can suffer a greater bit error rate. Accordingly, the most important bits are encoded into a (7,k) 8-ary Reed Solomon code where 7 is the length of the code and k is the dimension of the code. The less important bits are then respectively encoded into a (7,k+1) or a (7,k+2) 8-ary Reed Solomon code. The code words are modulated onto a plurality of tones or subcarriers. The decoding is effected by initially demodulating the subcarriers and generating a candidate set of code words from each 7-tuple of demodulated 8-ary symbols corresponding to a transmitted code word.

Abstract: Selected variables of a fluid flowing through a conduit are measured by transmitting acoustic pulses through the conduit wall and fluid stream along normal and oblique transmission paths between acoustic transducers located externally of the conduit, measuring the transit times of the pulses between the transducers, and combining these transit times with certain conduit and transducer parameters according to predetermined mathematical relationships to obtain the values of the variables. The variables which may be measured are flow velocity, mass flow rate, sonic velocity of the fluid, fluid compressibility, fluid temperature, and fluid density.

Abstract: A dynamic positioning system for a sea-going vessel containing an ocean thermal energy conversion (OTEC) system utilizes the thrust produced by the sea water effluents resulting from the energy conversion process to position the vessel against wind and ocean current forces. In one preferred embodiment applicable to both cylindrical surface and spar buoy types of vessels, both the warm water and cold water discharges are collected in a common annular plenum and then discharged through nozzles spaced angularly around the periphery of the plenum. Each nozzle is rotatable through a 90.degree. arc in a vertical plane to alter the direction of the discharge water jet and thereby to alter the horizontal component of the thrust or the driving force acting upon the vessel. The nozzles may be selected as to location and angular orientation to attain the net resultant force vector necessary to provide station-keeping or propulsion to the vessel under most any combination of wind and ocean current conditions.

Abstract: A bifilar helical antenna which will radiate or receive in the backfire mode. The antenna consists of two interlaced helixes fed at the tip. Each helix is fed by a transmission line with energy of equal amplitude but 180.degree. out of phase. Optionally the helixes may be connected to a ground plane at the far end for mechanical stability. For the same reason an insulating right cylinder may be used to support the helixes. The two helixes have such a diameter and such a pitch or pitch distance that the currents flowing from their terminals to the far end are out of phase while the currents flowing in the reverse direction are in phase to provide a fast pseudo wave structure.

Abstract: A parabolic dish is constructed by forming from relatively thin flexible sheet material a planar assembly of relatively narrow curved strips arranged side by side and having arcuate longitudinal edges which conform to curves defined by certain parametric equations, such that the strip assembly may be deformed to a parabolic dish configuration wherein the adjacent strip edges are disposed contiguous one another in planes parallel to a plane containing the principle axis of the dish, and joining the strips of the deformed strip assembly to retain the latter in its parabolic dish configuration.

Abstract: A fiber reinforced composite tube is molded by applying an annular, liquid-resin-impregnated layer of reinforcing fibers to a cylindrical mold or mandrel; placing in contact with the exposed surface of the fiber-resin layer a compression sleeve which is split lengthwise to permit circumferential contraction or expansion of the sleeve into pressurizing relation with the layer; pressurizing the compression sleeve with fluid pressure to compress the fiber-resin layer and thereby compact the reinforcing fibers and expell entrapped air and excess resin from the layer; and curing the resin while the fiber-resin layer is so compressed.

Abstract: An electrical structure having a wire conductor secured to a supporting substrate is fabricated by stitching the substrate with a sewing machine using a wire as one sewing filament of the machine. The particular electrical structure described is a parabolic antenna having a wire screen reflector consisting of a plurality of wire screen sections or "squares" secured in checkerboard fashion to a supporting frame with the edges of adjacent squares in electrical contact. Each square is fabricated by utilizing the wire stitching technique of the invention to lock stitch a supporting substrate in a grid pattern consisting of the stitched wires disposed in intersecting parallel rows and electrically joined to one another at their intersections to form a screen square.

Abstract: A holographic optics orientation assembly for a holographic recording unit having a laser holographic recording system for recording holograms of subjects situated within a holographic recording field of the recording system. The orientation assembly is adjustable to adjust or shift the recording field without moving the entire recording unit and thereby permit pointing or aiming of the recording system at a selected subject without moving the entire unit.

Abstract: An extremely low frequency (ELF) Communication System is disclosed for worldwide communication from land to receiving stations thousands of miles away using the existing DC power transmission lines of the Pacific Intertie power transmission system as the antenna. An ELF communication system requires a very long uninterrupted antenna or a series of long parallel antennas. The transmission lines of the Pacific Intertie DC power system lend themselves to be used as the required long antenna for the disclosed ELF system. The DC lines together with the associated ELF transmitter and coupling devices comprise the global ELF communication system disclosed herein.

Abstract: A resiliently compliant, variable stiffness wire mesh structure, primarily for space applications, characterized by its lightweight construction, its compact stowage and deployment capability, and its ability to maintain its nominal shape under widely varying thermal conditions. The structure has a frame supporting a wire mesh including spring-like longitudinally compliant wires which are terminally secured to the frame to constitute primary structural elements of the mesh and are prestressed in a manner such that the compliant spring wires in different sections of the mesh have differing spring rates or stiffness. This non-uniform stiffness of the mesh is designed to maintain the mesh taut under widely varying thermal conditions and thereby avoid the formation of slack in the mesh wires which would allow out-of-plane displacement of the mesh. The described mesh structure is a wire mesh antenna reflector for space applications.

Abstract: A wire mesh structure, primarily for space applications, characterized by its lightweight, its compact stowage and deployment capability, and its ability to maintain its shape under widely varying thermal conditions. The structure has a frame supporting a wire mesh including wires which are terminally secured to the frame and constitute the primary structural elements of the mesh. These structural wires are preformed to a spring-like configuration which renders the wires resiliently compliant with a low spring rate in the endwise direction and are stretched to produce a predetermined tension preload in the wires when the mesh is installed on the supporting frame. This preload retains the mesh in a taut condition under widely varying thermal conditions and thereby prevents the formation of slack in the mesh which would allow out-of-plane displacement of the mesh.

Abstract: 1. A correlation system for two complex multifrequency input signals which may contain relatively strong narrow band components including the combination of: auto-correlator means responsive to one of the input signals, the auto-correlator means dividing the one input signal into two channels and including delay means in one of the channels for introducing a fixed relative timing displacement between the two signals, threshold means coupled to the auto-correlator means for indicating when the auto-correlation output signal exceeds a selected amplitude, first and second delay means each responsive to a different one of the input signals and introducing like delays thereto, gating means coupled to at least one of the delay means and controllably responsive to the threshold means, and correlator means coupled to said delay means and said gating means for correlating the two input signals therefrom.

Abstract: A thick layer of silicon dioxide is grown on a semiconductive substrate and then etched to form an elongated opening that defines the outer boundaries of a diffused transistor. The thick silicon dioxide layer serves as a permanent fixed, diffusion mask. The first diffusion is performed through the permanent mask opening. Thereafter, portions of the elongated opening are masked by secondary thin layers of silicon dioxide or photo-resist, and subsequent diffusions are performed through different unmasked portions of the elongated opening.

Abstract: There is disclosed a method and apparatus for measuring electromagnetic conductivity within a medium to thereby derive a measurement of the rate of propagation of a magnetic field therein. If one then measures the return time of a pulse transmitted in the medium when a conductivity anomaly is encountered which creates a reflection, a magnetic diffusion radar can be calibrated. This technique enables one to measure the conductivity of a propagation medium such as salt water, earth or the like for any desired purpose such as determining the salinity of sea water or river water. More particularly, however, this enables one to make such a measurement in order to provide an electromagnetic anomaly detector such as is used in metal locaters, mine detectors, and in geophysical prospecting or exploration.

Abstract: A relatively low frequency linear element antenna characterized by its lightweight construction, relatively wide band width, and elastic strain energy deployment capability. The antenna has a plurality of slender electrical conductors such as wires forming radiating elements secured to a supporting tube with the conductors extending lengthwise of and spaced about the tube wall and electrically joined at the base end of the tube in such a way that the antenna has the same radiation characteristic as a conventional cylindrical antenna of the same diameter as the tube. The base ends of the conductors are gathered for connection to the center conductor of a coaxial antenna feed line to provide an impedance match between the antenna and coaxial line. The antenna supporting tube may comprise a thin-walled, resiliently flexible, strain energy deployable tube to permit contraction of the antenna to a folded or coiled packaged configuration and antenna deployment by elastic strain energy stored in the contracted tube.

Abstract: A digital speech compression system uses a predictive feedback loop. The digital speech signals are compressed within the feedback loop for reducing the transmitter bandwidth. The system comprises a first adder into which the digital signal is fed followed by a quantizer and a compression logic. The predictive loop includes a second adder coupled to the compression logic and followed by a digital predictive filter. The output of the filter is impressed in a negative sense on the first adder and in a positive sense on the second adder. Specifically, the quantizer and compression logic may consist of a two-valued limiter followed by a compressor and a converter in the feedback loop or alternatively the limiter may be followed by a converter while the compressor is disposed outside the feedback loop to provide sample by sample compression.

Abstract: A work clamp for clamping a workpiece to a work table with a clamp member which extends and retracts to and from clamping position with a compound motion having components parallel to and normal to the table in a manner such that extensile movement of the member occurs both parallel to the table to a position over the workpiece and toward the table to clamp the workpiece against the table, and retractile movement of the member occurs both away from the table to release the workpiece and parallel to the table to clear the workpiece for removal from and placement on the table.

Abstract: In a charge coupled device provided with a two-phase overlapping gate structure, charge flow directionality is built into the structure by forming an asymmetrical potential well beneath each gate electrode with a single offset mask. High packing density is achieved in an array of staggered bits and with each bit being designed to have a geometry of minimum size.