Abstract: An expandable metal membrane of the type used to contain cryogenic liquids is disclosed. The membrane utilizes two sets of triangular shaped corrugations at right angles to each other. The corrugations are arranged so that the membrane expands only along one axis at each intersection of the corrugations and the expansion of the membrane along two axes simultaneously is assisted by the rotation of the panel enclosed by each two sets of corrugations.

Abstract: A device for feeding letter mail and the like from a stack of such non-uniform sheet-like articles for individual workpiece processing wherein a plurality of friction feeders define a path for the transfer of mail from the stack and are driven in a pulsing mode interdependently under the control of photoelectric cells to facilitate the automatic separation of workpiece doubles.

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: In a reactive metal-water electrochemical cell, an alkaline electrolyte containing organic additives which reduce the parasitic direct corrosion reaction between the reactive metal and the water of the electrolyte. More particularly, the additives substantially reduce the activity of the water by forming inter-molecular hydrogen bonding between the organic additive and water. Illustratively, such organic additives include alcohols, nitrogen containing compounds such as amides, amines and hydrazine, and ketones, ethers and esters. Optionally, molarity of the electrolyte is controlled independent of water additions by chemically removing the reactive metal ions formed during discharge of the cell. This is accomplished by the controlled additions of precipitating agents to the electrolyte to form insoluble salts.

Abstract: A system for maintaining a two-legged hydrophone array in a horizontal plane is disclosed. This system uses a pair of directional maneuverable drogue chutes for providing tension on the hydrophone arrays and for maintaining the desired angle between the two legs.

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: Apparatus includes an offshore platform riser subtended by a joint chamber having port means for receiving a subsea pipeline and access means for a submersible capsule. The riser and chamber are attached to the platform in such manner as to provide for thermal expansion and to permit detachment when an abnormal loading is encountered. Platform winch means attached to cable means passing through the riser and chamber are used to pull an end of the pipeline into the chamber. Personnel utilizing the capsule then enter the chamber for completing the joining of the pipeline and riser. The joining and subsequent inspection operations are conducted at substantially atmospheric conditions in the chamber.

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.

Abstract: An improved system of pitch control for aircraft having a "flying tail"; i.e., a movable horizontal stabilizer with at least one movable elevator thereon. The human or automatic pilot input commands operate the elevators, and then the elevator response is used as part of the command to operate the stabilizer.

Abstract: A method for detecting and monitoring corrosion by sensing the spontaneous propagation of elastic waves produced in materials as the result of corrosion phenomena. Certain corrosion reactions generate elastic waves (sounds) which may be detected by sufficiently sensitive instrumentation to provide an identifiable acoustic signature. Correlation of these signatures with known standards provides a non-destructive inspection technique for monitoring invisible or hidden corrosion. In addition to acoustic emissions generated by the low-level oxidation/reduction reactions characteristic of corrosion processes, the invention includes the application of a thermal input to the test specimen to enhance the acoustic signals produced by the corrosion phenomena. By measuring the rate of acoustic pulse emission, the cumulative count of acoustic pulses generated, and the pulse amplitudes of the acoustic emissions, correlation may be made with empirically obtained data to permit failure prediction.

Abstract: An improved fastener system is derived for cold working the surfaces defining aligned fastener holes in structural members and installing fasteners therein. Essentially, an integral fastener and mandrel construction facilitates the insertion of a sleeve into the holes, an expansion of the sleeve thus disposed to thereby cold work the surfaces of the members defining the holes, and the pulling of the fastener into the holes thus prepared and sleeve-lined. A frangible neck is provided between the fastener element and the mandrel element which permits the breaking off and discarding of the latter after the former is installed. Retenion means is then installed, formed or otherwise provided on the fastener end in conventional manner. Thus, cold working and fastener installation is accomplished in only two steps due to the critical design and configuration of the combined fastener, break-off groove and mandrel.

Abstract: A compact, portable electrical discharge metalworking machine for off-hand use and general applicability. The invention is a lightweight, versatile gun type tool which has air and water cooling of electrode and work, a vibrating electrode to facilitate its motion inside the work, a simple, automatic, spring driven, all orientation electrode feed, and uses low voltage, high amperage electricity.

Abstract: This hand held universal radome tester is an instrument for locating discontinuities and impurities inside a radome wall and for determining the quality of an anti-static paint coating over the exterior surface of a radome. It includes a microwave segment which is energized in the discontinuities/impurities mode of operation to measure energy reflected by the radome wall, and a dc segment which is energized in the anti-static paint tester mode to measure resistance in megohms per square. The tester is battery-operated making it a completely portable device.

Abstract: This invention relates to a steerable articulation coupler for effecting rapid connection of the two sections of a ground vehicle. The coupler also provides for rapid automatic connection of the power transmission shaft. The coupler consists of a socket member and an insertion member. The insertion member includes a forward semi-spherical support surface, a rearward large diameter support surface, a guide receptacle and a set of alignment members. Counterparts on the socket member cooperate with the insertion member to align the two members.

Abstract: This invention discloses the combination of (1) a liquid temperature conditioning apparatus located exteriorly of a potential explosion sustaining zone, (2) an explosion proof air-liquid heat exchange device located within a potential explosion sustaining zone, and (3) air ducts interconnecting the air-liquid heat exchange device with the interior of a compartment open to the ambient and containing explosion sustaining vapors, such as the interior of an integral fuel tank compartment in an aircraft containing vapors arising from highly volatile hydrocarbon fuels normally carried therein.