Abstract: A space spider crane 15 is provided for the movement, placement, and/or assembly of various components on or in the vicinity of a space structure 120. Space spider crane 15 is comprised of a small central body 16 to which manipulators 24 and legs 25 are attached. The legs 25 are equipped with constant pressure gripping end effectors 29 to safely grip space structure 120. Walking by legs 25 or repairing and placing by the manipulators 24 may be controlled either by computer software 140 or a remotely situated human operator 135, who maintains visual contact with the space spider crane via television cameras 22 located at strategic positions on space spider crane 15. One possible walking program consists of a parallel motion walking program that results in small central body 16 alternatively leaning forward and backward relative to end effectors 29.

Abstract: A composite piston structure is disclosed which provides a simple and reliable means for joining a carbon-carbon or ceramic piston cap 11 with a metallic piston body 13. Attachment is achieved by means of a special geometry which compensates for differences in thermal expansion without complicated mechanical fastening devices. The shape employs a flange created by opposed frustoconical shapes 12 and 19 with coincident vertices 15 intersecting on the radial centerline of the piston in order to retain the piston cap. The use of carbon-carbon for the piston cap material allows a close fit between the piston and a cylinder wall, eliminating the need for piston rings. The elimination of extra mechanical parts of previous composite pistons provides a lightweight composite piston capable of extended high temperature operation.

Abstract: A multi-body aircraft with an all-movable center fuselage 20 which translates relative to two side fuselages 22. At subsonic and transonic flight the center fuselage 20 is in a forward position. At supersonic speeds the center fuselage 20 moves aft so as to ensure optimum aerodynamic interference at particular Mach numbers. This provides an increased shock strength and greater surface area so that significant reductions in zero-lift wave drag can be achieved. This concept allows for a significant increase in the wing aspect ratio which would improve high-lift performance at all speed without incurring a significant supersonic zero-lift wave drag penalty. In addition, an improved low-fineness ratio, high-speed performance is achieved at all speeds and for all flight conditions.

Abstract: A crossflow vorticity sensor is provided for the detection of crossflow vorticity characteristics. The crossflow vorticity sensor is comprised of crossflow sensors (10) which are non-invasively adhered to swept wing laminar surface (12) either singularly, in multi-element strips (11), in polar patterns (40), or orthogonal patterns (41). These crossflow sensors (10) are comprised of hot-film sensor elements (18) which operate as a constant temperature anemometer circuit to detect heat transfer rate changes. Accordingly, crossflow vorticity characteristics are determined via cross-correlation. In addition, the crossflow sensors (10) have a thickness which does not exceed a maximum value h in order to avoid contamination of downstream crossflow sensors (10).

Abstract: A power supply is provided for an arc discharge lamp (38) which includes a relatively low voltage high current power supply section and a high voltage starter circuit (10). The low voltage section includes a transformer (15), rectifier (24), variable resistor (26) and a bank of capacitors (28), while the starter circuit (10) comprises a plurality of diodes (D1 to D12) and capacitors (C1 to C12) connected as a Cockcroft-Walton multiplier. The starting circuit is effectively bypassed when the lamp arc is established and serves to automatically provide a high starting voltage to re-strike the lamp arc if the arc is extinguished by a power interruption.

Abstract: An energy absorbing device used as a load limiting member in a structure to control its response to applied loads is disclosed and functions by utilizing a spool assembly 20 having flanged ends 36 and an interior cavity 34 of sufficiently large diameter to cause it to deform plastically at a prescribed load. In application, the spool 20 is utilized as a pivot point for the legs 14 of an aircraft seat 12. When properly designed and integrated into the seat arrangement 10, the spool 20 will twist about its axis, deforming plastically when the impact load exceeds the spool yield value. Through this deformation, spool 20 absorbs the kinetic energy of the movement of seat 10 at a substantially constant rate, thereby controlling the level of loads transmitted to the seat occupant. By proper sizing and selection of materials, it is possible to control load response in a predictable manner.

Abstract: A material specimen 12 containing a central hole is bolted (bolt 27) between two bearing guide plates 28 and 29. An applied load control 11 applies an applied load, either tension or compression, to one end of specimen 12 and a bypass load control 13 applies a bypass load to the other end of specimen 12. Both load controls have their control inputs supplied by a single input signal generator 24. The difference between the applied load and the bypass load is transmitted through bolt 27 and plates 28 and 29 to bearing load cells 30 and 31.

Abstract: A novel series of polymers and copolymers based on a polyimide backbone with the incorporation of carbonate moieties along the backbone. The process for preparing these polymers and copolymers is also disclosed as is a novel series of dinitrodiphenyl carbonates and diaminodiphenyl carbonates. The novel polymers and copolymers exhibit high temperature capability and because of the carbonate unit, many exhibit a high degree of order and/or crystallinity.

Abstract: A polyether graft copolymer with improved solvent resistance and crystalline thermally reversible crosslinks. The copolymer is prepared by a novel process of anionic copolymerization. Polymers formed in this manner have good solvent resistance and are well suited for commercial aircraft parts.

Abstract: The invention is a tool and process to be used in explosive joining of tubes. The tool consists of an initiator 81, a tool form 82 and a ribbon explosive 25. The assembled tool 80 is a compact, storable and safe device suitable for explosive joining of small, lightweight tubes down to 0.20 inch in diameter. The invention is inserted into a tube 51 to be welded which tube has itself been inserted into either another tube 52 or a tube plate. A shim or standoff between the two surfaces to be welded is necessary. Initiation of the explosive inside the tube results in a high velocity, angular collision between the mating surfaces. This collision creates surface melts and collision bonding wherein electron-sharing linkups are formed.

Abstract: A helicopter 10 with a system for controlling mainrotor torque which reduces the power and size requirements of conventional anti-torque means. The torque countering forces are generated by disrupting the main rotor downwash flowing around the fuselage. The downward flow is separated from the fuselage surface 11 by strakes 16 and 17 positioned at specified locations on the fuselage 11. These locations are determined by the particular helicopter wash pattern and fuselage configuration, generally being located 30.degree. before top dead center 21 and 30.degree. from bottom dead center 22 on the fuselage side to which the main rotor blade 12 approaches during rotation. The strakes 16 and 17 extend along the fuselage 11 from the cabin section 18 to the aft end and can be continuous or separated for aerodynamic surfaces such as a horizontal stabilizer 15.

Abstract: The invention is a system of flow control devices which result in reduced skin friction on aerodynamic and hydrodynamic surfaces. The devices cause a breakup of large-scale disturbances in the boundary layer of the flow field. Referring to FIGS. 1 and 2, the riblet device 10 acts to reduce disturbances near the boundary layer wall by the use of longitudinal striations forming vee-shaped grooves. These grooves are dimensional on the order of the wall vortices and turbulent burst dimensions 31 depicted in FIG. 3. The large-eddy breakup device 41, depicted in FIGS. 4 and 5, is a small strip or airfoil which is suspended in the upper region of the boundary layer. Various physical mechanisms cause a disruption of the large-scale vortices. The combination of the devices of this invention result in a substantial reduction in skin friction drag.

Abstract: A device to determine the operable failure mode of mechanically fastened lightweight composite joints by measuring the hole elongation of a bolted joint is disclosed. The double-lap joint test apparatus 10 comprises a stud 20, a test specimen 30 having a hole, two load transfer plates 31, and linear displacement measuring instruments 27. The test specimen 30 having a hole is sandwiched between two load transfer plates 31 and clamped together with the stud 20. Spacer washers 22 are placed between the test specimen 30 and each load transfer plate 31 to provide a known, controllable area for the determination of clamping forces around the hole of the test specimen 30 attributable to bolt torque. The spacer washers 22 also provide a gap for the mounting of reference angles 23 on each side of the test specimen 30. Under tensile loading, elongation of the hole of test specimen 30 causes the stud 20 to move away from the reference angles 23.

Abstract: This invention is a lightweight, universal connector that joins stringers at various angles. The connectors 10 are fabricated from fiber-epoxy resin strips that wrap around stringers 30 and have ends, tabs 16 and 18, which extend in one general direction. The inside surface of the first tab 16 lies on a plane defined by the stringers being joined, and the second tab 18 is separated from the first tab 16 by a distance equal to their thickness. Stringers 30 of different shapes and sizes are joined by alternately bonding the first tab 16 of one connector between the first 16 and second 18 tabs of another connector. Tee-joints are formed by using web elements 41 and 42 which each partially wrap around a stringer 3010 and have tabs 411 and 421 which are offset, and are bonded between tabs 16 and 18 of universal connectors 109 and 1010 bonded to another stringer 309. Sharp corners are trimmed from the tabs so that a gusset area remains between the stringers for support.

Abstract: Method and apparatus for obtaining dynamic calibrations of pressure transducers. A calibration head (15), a flexible tubing (23) and a bellows (20) enclose a volume of air at atmospheric pressure with a transducer (11) to be calibrated subject to the pressure inside the volume. All of the other apparatus in the drawing apply oscillations to bellows (20) causing the volume to change thereby applying oscillating pressures to transducer (11) whereby transducer (11) can be calibrated.

Abstract: This invention relates to a system for protecting an in-air vehicle from damage due to the craft sustaining a lightning strike. It is an extremely simple device consisting of a sacrificial graphite composite rod 40, approximately the diameter of a pencil with a length of about five inches. The sacrificial rod 40 is constructed with the graphite fibers running axially within the rod in a manner that best provides a path of conduction axially from the trailing edge of an aircraft to the trailing end of the rod. Sacrificial rod 40 is inserted into an attachment hole 32, machined into trailing edges of aircraft flight surfaces, such as vertical fin cap 31, and attached with adhesive in a manner not prohibiting the conduction path between the rod 40 and aircraft 10. The trailing end of rod 40 may be tapered for aerodynamic and esthetic requirements. This rod is sacrificial but has the capability to sustain several lightning strikes and still provide protection.

Abstract: A process for the preparation of transparent silica gels which can be used as crystal growth media is disclosed. A quantity of cation exchange resin beads is placed in a solution of a soluble potassium salt and stirred for several hours to allow the potassium ions to replace the cations on the resin beads. The supernatant liquid is then decanted through a filter, and the treated resin beads are rinsed with distilled water to remove excess salts. The treated resin beads are then transferred into a sodium silicate solution. The resulting mixture is stirred to allow the potassium ions on the treated resin beads to exchange with the sodium ions in the sodium silicate solution. The treated silicate solution is then poured through a coarse filter. A volume of boiled, cooled distilled water is added to a volume of the treated silicate solution, after which a volume of acetic acid solution is added to the mixture of distilled water and treated silicate solution.

Abstract: Semi-2-interpenetrating polymer networks (semi-2-IPNs) of improved qualities are prepared by combining a linear polymer and a cross-linkable oligomer which have identical recurring units. Linear and crosslinking components having identical structures in their backbones are mutually soluble and will thus form one homogenous phase unlike other network system. A novel semi-2-IPN of the present invention is prepared by combining a linear polyimidesulfone with a cross-linking acetylene-terminated polyimidesulfone. This combination results in a semi-2-IPN of improved strength, adhesion, and processability.

Abstract: A full-color, flat-panel, matrix-addressed, electroluminescent display 10 is achieved using red, green and blue phosphors in two layers separated by layers of insulating material 16, 20, 24 and 30 and layers of row 22 and column 14 and 32 electrodes used to excite the phosphors when voltage is applied. One phosphor layer is all one color 18 while the second phosphor layer is composed of alternating, side-by-side stripes of a second color 26 and a third color 28. At each intersection of the row 22 and column 14 and 32 electrodes, a picture element is formed by the two side-by-side color phosphors 26 and 28 as they are superimposed over the single color 18 layer.

Abstract: This invention is a device which allows for expeditious and repeated changeovers between pressure and force testing and which uses minimum internal volume of a wind tunnel test structure (24). A matrix configuration of holes (30) is located on the outer surface of the structure (24). Pressure tubes (27) lead through the internal cavity of the structure (24) from test sites (29) to this outer surface matrix configuration (30). A pressure tube connector (12) with a corresponding matrix of holes (17) is connected to the surface of the structure (24). Pressure tubes (11) leading from remotely located transducers (not shown) are joined to the connector (12), thus forming pressure passageways from the test sites (29) to the transducers (not shown) to allow for pressure testing. When force testing is required, the pressure tube connector (12) is disconnected and a cover plate (20) is connected. The cover plate (20) seals the exposed internal pressure tubes (27).