Abstract: Effective utilization of pellets of material capable of subliming under conditions of use in a sandblasting process in which such pellets are propelled against a surface by a stream of pressurized gas requires careful control of a number of interrelated factors. When the process is employed for the purpose of removing material from a surface the pellets used should preferably have sharp edges and corners. Further, they should be employed so that they will hit against such a surface as rapidly as reasonably possible. Preferably these pellets are both agitated and subjected to alpha radiation as they are held prior to being entrained into a stream of moving gas and as they are introduced into such a stream. Further, preferably the particles are discharged against the surface being treated through a so-called "sonic nozzle" so as to maximize their momentum as they are directed toward the surface being treated.

Abstract: The control system includes a sensing mechanism by which a true pure signal from flapping bending activity resulting from an external load force on a rotor blade in a rotor system is generated and fed back to a gyroscope which then precesses to return a correcting feathering motion to the rotor blade through a swashplate. Such generation is developed by the sensing mechanism which comprises a cantilevered beam or spring system secured at its one end to a fixed hub arm about which the blade feathers and having its other end operatively connected to the gyroscope. The gyroscope is positioned outside of a high force blade feathering loop and is independently sized from the rotor to which it is coupled. The system also provides for pilot command input to produce a control feathering motion to a pair of blades independently of the sensing means.

Abstract: A navigation method and system suitable for highly accurate all-weather navigation of vehicles such as ships and aircraft. An initial position of the vehicle relative to a plurality of known points each located at predetermined geographic positions is first determined. The distance or range of the initial position from each of the plurality of known points is determined and when the vehicle moves to a second and unknown position, the difference between the propagation time of electromagnetic wave energy transmitted from each of the plurality of known points at the initial and second positions is determined to thereby determine an incremental change in the distance to the second position from each of the plurality of known points.

Abstract: This device generates a simulated acoustic emission signal and simultaneously introduces the signal into a test article. The device provides a means for positioning precision brittle tubes or rods against the test article in a controlled fashion. A simulated signal, a stress pulse, is introduced into the test article at a point source when sufficient force is applied to break the tubes or rod against the test article. The stress pulse is generated by the rapid release of elastic energy within the test article itself therefore it very closely simulates the acoustic emission signal generated by a flaw in the material.

Abstract: An improved manufacture including a fiber-reinforced epoxy composite joint, and the method for producing same, in which the fibers of each of the composite adherends pass through and are intermeshed across the joint bondline. A scarfed mating surface is prepared on the end of each of the adherend elements-to-be-joined, after which a chemical etching of the mating ends to obtain exposed lengths of filaments or fibers is provided. A sheet of unsupported adhesive material is inserted between the scarfed and etched mating surfaces prior to their layup, after which heat and pressure are applied for bonding the joint. The exposed fibers of each element cross the bondline to intermesh with those of the other element during the melting of the unsupported adhesive. This process increases the joint efficiency to 83% of the efficiency of a non-joined element.

Abstract: An oil replenishment system provides a remote reserve oil tank and the plumbing necessary to fill the main oil tank or tanks of engines, especially aircraft engines during flight. This system includes apparatus to determine the quantity of oil pumped to any one engine so that a quantity gauge is not required on the engine. A selector valve located on the reserve tank which may be remotely controlled directs replenishment oil to the selected engine tank. The system is designed to be powered from the existing on board hydraulic power system.

Abstract: Actuator for selectively and sequentially providing dual pressure forces for positioning and seating fasteners and for other purposes. Air pressure is selectively applied to a first piston to apply a relatively low level of hydraulic pressure to the actuating rod and then to a second pneumatic piston to intensify the hydraulic pressure applied to the actuating rod. The actuator is caused to be extended a first distance at low force and then to be extended an additional distance at a relatively higher force. Air pressure is selectively applied to cause all pistons and the actuating rod to retract to their initial positions.

Abstract: An accelerometer senses a machine's vibration resulting from unbalance of its internal rotors and outputs an electrical signal which is then conditioned by means of an amplifier and uniform level filter. The resulting output signal has individual vibration (frequency) components which are adjusted to match the machine's specified vibration limit extending over each of the rotors' frequency range to achieve a uniform level. A storage oscilloscope is employed to display the conditioned signal.By utilizing the uniform level filter a normal operating band for the machine can be specified in terms of oscilloscope divisions regardless of the machine's operating frequencies. When a signal exceeds the specified band on the oscilloscope the rotor causing the excessive vibration may then be determined by analyzing the individual components. Utilizing relatively uncomplicated electronics, a limit exceedance warning may also be incorporated.

Abstract: An assemblage of a rivet for securing at least a pair of sheets or other members, wherein the rivet is formed with a cavity in its upset end of predetermined dimensions with respect to the sheets and the remainder of the rivet. The cavity preferably terminates in the thickness of the bottom sheet, thus facilitating rivet upset while providing maximum strength.

Abstract: An articulated high "G" force aircraft seat which is movable between a conventional upright position and a reclined position. As described, the head and eyes remain in a relatively stationary position without affecting instrument monitoring or external vision. The aircraft controls remain within easy reach, yet the pilot is able to sustain high acceleration maneuvers in excess of eight "G's".

Abstract: An escape capsule integrally designed within a parent aircraft and having a fly-away capability throughout the entire speed range of the parent aircraft. The capsule utilizes segments of the leading edges of the aircraft wings to provide flight capability and stabilization to the capsule, an elevon system controlling the capsule about both its lateral and longitudinal axes, and rudder and vertical stabilizing elements for controlling the capsule about its vertical axis. A rocket is provided to supply the thrust necessary to accomplish positive separation of the capsule from the parent aircraft along a required trajectory. A thrust system, such as a turbojet or fan jet engine, is provided for sustaining the capsule in flight.

Abstract: A ski-type water borne craft adapted to plane along the surface of a body of water and having two stabilizing elements spaced laterally apart and mounted for upward and downward movement relative to one another in a relationship providing roll forces and giving lateral stability to the craft, with the stabilizing elements preferably being a pair of swinging flaps hinged to the after ends of two vertically shiftable hydroskis.

Abstract: A one-piece molded grommet for routing a cable inserted therethrough and to protect the cable from bending, cutting and foot traffic. A cavernous tab or foot in the form of a split sleeve portion disposed in a first plane is attached to a vertically oriented barrel portion through which an inserted cable is elevated from the cavity of the tab to a second plane generally parallel to the first. A flange member or pad is attached to the barrel portion at the second plane and includes a bore at an angle to the cable's introduction to the cavernous tab. A vertically oriented slit is provided in the barrel and the flange member to facilitate installation and removal of the cable to the grommet. The slit is off-center relative to the bore in order to provide a saddle of protective material for the cable therein should pressure be applied to the top of the grommet.

Abstract: A portable, relocatable, erectable building or shelter structure, and method of erecting, utilizing a pair of laterally spaced elongated and segmented base rail assemblies to which are pivotally connected a pair of erectable arch assemblies for each row of a plurality of panels slidably engageable along two opposite sides to each pair of adjacent erectable arch assemblies pivotally connected to the base rail assemblies. The opposite sides of the individual panels other than the panel sides engageable to the adjacent base pivotally connected erectable arch assemblies are configured such as to be sealingly interengageable with the adjacent panel on both sides.

Abstract: A method is disclosed for fabricating in a single stage hollow polymeric article of manufacture from a flexible fibrous material, regardless of the degree of complexity of the laminate. The material is applied to a hollow flexible envelope which includes a pattern of any degree of complexity and which is supported on a solid mandrel, to be encased in a two-part female die. The envelope and applied material are sealed off from the mandrel by means of film layers forming a bag. A vacuum is established within the bag, resulting in forces acting from the inner side of the envelope through it and the laminated material against the die walls. The support mandrel is removed, and the remaining assembly is cured under the vacuum with or without elevated pressures. After cooling, the die and envelope are readily removed from the article.

Abstract: Apparatus and method for measuring the impedance of oscillatory systems, or elements of such systems, which exhibit nonlinear behavior at high excitation amplitudes. Excitation of the element being tested, which element may be either acoustical, electrical, or mechanical, is in the form of a combination of a high-intensity biasing signal having a broadband spectrum, and a low-intensity pure sinusoidal tracer signal. The tracer signal is retrieved at an appropriate measuring point in the test system by means of highly-selective filtering. Although the broadband signal comprises the real or basic test signal input to the test element, the retrieved tracer signal is substituted therefor for the purpose of deriving the element's impedance through the use of conventional impedance algorithms. Algorithm solutions thus provided correspond to the response of the element to the entire spectrum of the broadband excitation.

Abstract: The strain energy that is released when a structural member fails is emitted, among other ways as a broad frequency acoustic emission which is detected by a piezoelectric crystal sized for a preselected natural frequency. This piezoelectric crystal converts the acoustic energy into an electronic signal which is filtered to permit passage of only predetermined frequencies. The filtered signals are then passed through a device which matches the line impedance. A differential amplifier provides signal amplification, and rejects noise, in the received signals which are then passed through a level detector, preset to only allow passage of predetermined signals which in turn trigger a latch for a light emitting diode indicating that a structural failure has occurred.A built-in tester allows for a periodic check to be made to insure system operation.

Abstract: An improved cooling system wherein printed circuit cards are made into modules of two cards each with an enclosed space between them inside the module. The modules cooperate with a rack which carries air passages, and upon connection of the module into the rack, air flows from one side of the rack through the module space, thus cooling the cards from their rear surfaces, thence out of the module, and returned via the other side of the rack.

Abstract: A novel improved urethane, urethane coating formed of epxoy resin and polyisocyanate for metallic or non-metallic substrates and the like exhibits improved resistance to blistering under high moisture conditions. The coating includes an epoxy resin having functional hydroxyl groups, for example, the reaction product of epichlorohydrin and bisphenol A. A hardener is included which comprises one or more selected polyisocyanates, preferably a mixture of a selected aliphatic biuret type polyisocyanate and an aromatic diisocyanate. A coupling agent, preferably an epoxy-containing silane, is included. A catalyst such as zinc octoate, pigments such as leachable chromates and organic solvent for the components may also be included. The pigments are held in suspension through the use of a suspending agent. The ratio of --OH groups of the epoxy resin to --NCO groups in the hardener is about 1:1.4-3.6.

Abstract: The invention discloses a new method of interconnecting a wiring system with an electrical junction box system. The junction box may be interfaced with the input wiring to the box by means of commercially available connectors. Internal wiring within the box is accomplished by means of a mother board carrying zero insertion force connectors and a matrix board which carries a customized interconnect program. The programmable matrix board is prefabricated and is insertable and removable to permit easy modification of the interconnect system.