Abstract: High temperature insulating articles are provided having improved performance characteristics. The articles comprise fabrics of closely woven refractory or heat resistant fibers having particles of silicon carbide dispersed at least partially through the fabric and bonded to the fibers with an emulsifiable polyethylene wax. Such articles exhibit significantly increased high temperature emittance characteristics and an improved retention of integrity and flexibility after prolonged exposure to high temperature.

Abstract: A gas piston driven hydraulic piston pump in which the gas cycle is of high efficiency by injecting the gas in slugs at the beginning of each power stroke. The hydraulic piston (40) is disposed to operate inside the gas piston (30), and the two pistons, both slidably but non-rotatably mounted, are coupled together with a rotating but non-sliding motion transfer ring (50) extending into antifriction grooves (46 and 37) in the sidewalls (42 and 32) of the two pistons. To make the hydraulic piston move at a constant speed during constant hydraulic horsepower demand and thus exert a constant pressure on the hydraulic fluid, these grooves are machined with variable pitches and one is the opposite of the other, i.e., the gas piston groove (37) increases in pitch during its power stroke while the hydraulic piston groove (46) decreases. Thus the motion transfer ring (50) is properly denominated a force multiplier ring. Any number of piston assembly sets may be used to obtain desired hydraulic horsepower.

Abstract: A method of repairing damage to a porous refractory material coated with a glass coating (16) comprising applying hydrolyzed tetraethyl orthosilicate to the damaged area, curing said tetraethyl orthosilicate, applying to said damaged area a pliable filler (30) comprised of hydrolyzed tetraethyl orthosilicate and powdered refractory substrate (11) and heating the damaged area to cure filler (30).

Abstract: A hydrolyzed tetraethyl orthosilicate is applied to the surface of a porous refractory substrate following which the substrate is heated to a temperature and for a period of time sufficient to bond the silica released from the tetraethyl orthosilicate to the substrate thereby densifying and strengthening the surface.

Abstract: A new and improved secure communication system is provided. A product code, formed from two pseudorandom sequences of digital bits, is used to encipher or scramble data prior to transmission. The two pseudorandom sequences are periodically changed at intervals before they have had time to repeat. One of the two sequences is transmitted continuously with the scrambled data for synchronization.In the receiver portion of the system, the incoming signal is compared with one of two locally generated pseudorandom sequences until correspondence between the sequences is obtained. At this time, the two locally generated sequences are formed into a product code which deciphers the data from the incoming signal. Provision is made to ensure synchronization of the transmitting and receiving portions of the system.

Abstract: An optical temperature gauge using a semiconductor crystal (12) having a band-edge shift property which is temperature dependent. An external narrow band light source (10) provides optical excitation through an optical fiber (11) and light energy thus passed through the crystal (12) is conveyed by a second optical fiber (13) to a light-to-electric transducer (14) at an external location, the crystal (12) thereby being locatable in cryogenic or other systems, to provide remote read-out. The light wavelength is varied (scanned) in a repetitive pattern in source (10), the instantaneous wavelength passing over the band-edge wavelength during each cycle of the scan. The timing of the crossover is related to the temperature of the crystal by electronic means (15 and 17). Several alternative elements of instrumentation are disclosed.

Abstract: An improved method for markedly increasing the bond strength between a rigid, porous refractory material and a non-rigid substrate by densifying the face of the rigid material opposing the substrate. Densification is accomplished by wetting the refractory material and then impregnating it with a composite slurry having a particle size to fill voids of the porous material.

Abstract: A multi-layer absorbent product (10) for use in contact with the skin to absorb fluids, the product having a water pervious facing layer (12) for contacting the skin, a first fibrous wicking layer (14) overlaying the water pervious layer, a first container section (17) defined by inner and outer layers (16, 18) of a water pervious wicking material between which is disposed a first absorbent mass (20), a second container section (26) defined by inner and outer layers (22, 24) of a water pervious wicking material between what is disposed a second absorbent mass (28), and a liquid impermeable/gas permeable layer (30) overlaying the second fibrous wicking layer.

Abstract: Input signals from sensor (S) in a redundancy management system are provided redundantly in parallel so that a primary control signal may be selected. Median value signals for groups of three sensors are detected in median value selectors (30, 32, 34, 36, 40) of selection filters (F). The detected median value signals are then also compared in a subtractor/comparator (38) to determine whether any of them exceed the others by an amount greater than the signal level for a failed sensor. If so, the exceeding detected medium value signal is sent to a control computer (10) as the primary control signal. If not, the lowest level detected medium value signal is sent as the primary control signal.

Abstract: Penetration apparatus, for very high temperature applications in which a base plug (12) is inserted into an opening through a bulkhead (11), the base plug (12) having a head shape (14b) seating against the highest temperature surface (11a) of the bulkhead, which may be the skin of the nose cone or other part of a space vehicle intended for nondestructive atmospheric reentry. From the second side of the bulkhead (11b) at which the less severe environment is extant, a bayonet plug (14) is inserted into the base plug and engages an internal shoulder (19) therein upon 90.degree. rotation. The bayonet plug (14) has an integral flanged portion (14a) and a pair of ramping washers (16 and 17) are located between the flange (14a) and the second bulkhead surface (11b) with a spacing washer (15) as necessary.

Abstract: A flush mounting, cavity-backed, dual orthogonal slot antenna in which improved radiation pattern characteristics are obtained by making the spiral slot pattern elliptical in the aperture plane. A cavity (11) and a flanged aperture plate (11a) are shown in which one slot pair (12 and 13) is orthogonal with respect to another slot pair (14 and 15) within the aperture plate (11a). Coaxial split-tube baluns (12a and 14a) are used to drive the junctions between corresponding slot pairs. Optional cavity dielectric (18) is provided and a drive coupling arrangement includes a four port comparator hybrid (30) having .ltoreq. and .DELTA. ports (17 and 16) respectively, for alternate excitation to produce a single lobe or a double lobe pattern with null. Switching apparatus is provided to connect a common terminal (26) to either of the ports (17 or 16).

Abstract: A self-clamping cutting tool which includes a handle (11) attached to a C-shaped housing (12) and has an opening (13) sized to admit a pipe (23). Rotatably mounted within the housing is a C-shaped tool body (24) carrying a set of clamping rolls (27, 28 and 31) and two support rolls (51 and 52) and an edged cutting roll (64). The support rolls are disposed to one side of the axis (29) of a pipe and the cutting roll is disposed to the other side of a pipe axis so that these rolls contact a pipe at three circumferential points. Cutter advancing apparatus (63, 65, 66, 67, 68) advance the cutting roll toward the support rollers. The support rolls and cutting roll are rotatable independently of the C-shaped housing. A one way ratchet mechanism (41, 43) disposed between the C-shaped housing and the C-shaped tool body permits operation by movement in one rotational direction about the pipe axis. In another embodiment, the tool body is rotated by a power driven mechanism (80- 87).

Abstract: Disclosed is a magnetically latching solenoid including a pull-in coil and a delatching coil. Each of the coils is constructed with a combination of wire materials, including material of low temperature coefficient of resistivity to enable the solenoid to be operated at cryogenic temperatures while maintaining sufficient coil resistance. An armature is spring-biased toward a first position, that may extend beyond the field of force of a permanent magnet. When voltage is temporarily applied across the pull-in magnet, the induced electromagnetic forces overcomes the spring force and pulls the armature to a second position within the field of the permanent magnet, which latches the armature in the pulled-in position. Application of voltage across the delatching coil induces electromagnetic force which at least partially temporarily nullifies the field of the permanent magnet at the armature, thereby delatching the armature and allowing the spring to move the armature to the first position.

Abstract: The occlusive cuff system of this invention comprises a pressure cuff and a source of regulated compressed gas feeding the cuff through an electrically-operated fill valve. An electrically-operated vent valve vents the cuff to the ambient pressure. The fill valve is normally closed and the vent valve is normally open. In response to an external start signal, a logic network opens the fill valve and closes the vent valve, thereby starting the pressurization cycle and a timer. A pressure transducer continuously monitors the pressure in the cuff. When the transducer's output equals a selected reference voltage, a comparator causes the logic network to close the fill valve. The timer, after a selected time delay, opens the vent valve to the ambient pressure, thereby ending the pressurization cycle.

Abstract: Methods, and apparatus for use therein, for determining organic carbon in aqueous solution which method comprises subjecting the aqueous solution to electrolysis, for generating oxygen from water, and simultaneously to ultraviolet radiation, for oxidation of substantially all organic carbon therein to carbon dioxide and subsequently measuring said carbon dioxide and relating the value to the concentration of organic carbon in said aqueous solution.

Abstract: A seal assembly for sealing a variable gap between the surface of a first element and a second element movable relative thereto. A seal may comprise a seal housing attached to the second element for movement therewith and having a sealing surface thereon and at least one elongated seal member carried by the housing having first and second conjugate sealing surfaces thereon, the first sealing surface for rubbing and sealing engagement with the first element surface and the second sealing surface for sliding and sealing engagement with the housing sealing surface. A biasing assembly may be carried by the housing for biasing the first and second conjugate sealing surfaces of the sealing member toward sealing engagement with the first element surface and housing sealing surface, respectively.

Abstract: A flush-mounted antenna assembly (10) including a generally rectangular, conductive, box structure (11) open along one face to form a cavity. Within the cavity a pair of mutually orthogonal dielectric plane surfaces (13) (14) in an "egg crate" arrangement are mounted normal to the plane of the open face, each diagonally within the cavity. Each dielectric plane supports a pair of printed circuit dipoles typically (16) each fed from the opposite side of the dielectric plane by a printed "cone-shaped" feed line trace (15) which also serves as an impedance matching device (19) and functions as a balun connected from an unbalanced strip line external feed (24 and 26).The open face of the conductive cavity can be flush mounted with a randome thereover, the assembly thereby being flush with the skin of a aircraft or space vehicle.

Abstract: Flame retardant, abrasion resistant elastomeric compositions comprised of thermoplastic polyurethane polymer and flame retarding amounts of a filler selected from decabromodiphenyloxide and antimony oxide in a 3:1 weight ratio, and decabromodiphenyloxide, antimony oxide, and ammonium polyphosphate in a 3:1:3 weight ratio respectively. Also, flame retardant, abrasion resistant, and heat sealable coated fabrics employing such elastomeric compositions as coating film.

Abstract: In a hydrazine powered engine, an intake valve arrangement for positively controlling the opening and closing of the poppet valve in a hot gas cylinder, the poppet valve being operated by the piston and gas pressure only. The poppet valve uses a pneumatic "spring" which holds the poppet valve against the piston while the valve is opened and closed. To accomplish this, a poppet valve is slidably mounted in a "pneumatic spring" chamber which reaches a pressure approaching the gas supply pressure and, during the opening of the valve, the "spring" chamber retains enough pressure to hold the poppet valve onto the piston. In addition, the bottom of the poppet valve can have a suction cup type configuration to hold the poppet valve on the piston during the down stroke.

Abstract: A urine collection device for females comprising an interface body having an interface surface for engagement with the user's body. The interface body comprises a forward portion defining a urine-receiving bore having an inlet in the interface surface adapted to be disposed in surrounding relation to the urethral opening of the user. The interface body further comprises a rear portion integrally adjoining the forward portion and having a non-invasive vaginal seal on the interface surface for sealing the vagina of the user from communication with the urine-receiving bore. An absorbent pad is removably supported on the interface body and extends laterally therefrom. Also disclosed is a garment for supporting the urine collection device.