Abstract: A window construction is disclosed wherein a unitary vinyl seal 36, corresponding in shape to the window sash 20 and frame 18, is employed to seal the translucent panes 28, 30, 31, etc., in position. Double-backed adhesive foam tape strips 38, 40, 42, 44, 45, 46, etc., serve to sealingly bond vinyl seal 36, 36a, and 66 to the translucent panes, the associated sash 20 and frame 18 structure. Replacement of broken panes involves cutting around the periphery of the broken pane (FIGS. 6 and 7), removing the cut segment, installing a replacement pane and sealing it in position. The same segment of vinyl seal 36 removed, or a new seal 66 cut or formed to the same dimensions as the segment cut away, is employed to seal the replacement pane 28a in position. Sealing of the new seal (FIG. 7) is accomplished by an essentially triangular strip of adhesive foam tape 68 having adhesive on all surfaces thereof. Similar replacement seals can also be formed from the embodiments illustrated in FIGS.

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 mobile remote manipulator system 10 is disclosed for assembly, repair and logistics transport on, around and about a space station square bay truss structure. The vehicle is supported by a square track arrangement supported by guide pins integral with the space station truss structure 12 and located at each truss node 40. Propulsion is provided by a central push-pull drive mechanism 20 that extends out from the vehicle one full structural bay over the truss and locks drive rods 38 into the guide pins 30. The draw bar is now retracted and the mobile remote manipulator system is pulled onto the next adjacent structural bay. Thus, translation of the vehicle is "inchworm" style. The drive bar can be locked onto two (2) guide pins while the extendable draw bar is within the vehicle and then push the vehicle away one bay providing bi-directional push-pull drive.

Abstract: A deployable geodesic truss structure can be deployed from a stowed state to an erected state. The truss structure includes a series of bays, each bay having sets of battens connected by longitudinal cross members which give the bay its axial and torsional stiffness. The cross members are hinged at their mid point by a joint so that the cross members are foldable for deployment or collapsing. The bays are deployed and stabilized by actuator means connected between the mid point joints of the cross members. Hinged longerons may be provided to also connect the sets of battens and to collapse for stowing with the rest of the truss structure.

Abstract: The synthesis and characterization of several polyenamine ketones are discussed wherein conjugated diacetylenic diketones and aromatic diamines are used as a route to the formation of high molecular weight polyenamine ketones which exhibit good mechanical properties and can be cast into creasible films. Typical polymerization conditions involved the reaction of stoichiometric amounts of 1,4- or 1,3-PPPO and a diamine at 60.degree.-130.degree. C. in m-cresol at (w/w) solids content of 8-26% for a specified period of time under a nitrogen atmosphere. Novel polyenamine ketones were prepared with inherent viscosities as high as 1.99 dl/g and tough, clear amber films with tensile strengths of 12,400 psi and tensile moduli of 397,000 psi were cast from solutions of the polymers in chloroform. The polymers exhibited T.sub.g s as high as 235.degree. C. and weight losses of 14% after aging at 232.degree. C. in circulating air for sixty hours.

Abstract: This invention relates to a process using a Diels-Alder reaction which increases the molecular weight and/or crosslinks polymers by reacting the polymers with bisunsaturated dienophiles. The polymer comprises at least 75% by weight based on the reaction product, has a molecular weight of at least 5000 and a plurality of conjugated 1,3-diene systems incorporated into the molecular structure. A dienophile reaction with the conjugated 1,3-diene of the polymer is at least 1% by weight based on the reaction product. Examples of the polymer include polyesters, polyamides, polyethers, polysulfones and copolymers thereof. The bisunsaturated dienophiles may include bis-maleimide, bisnadimides, bis maleic and bis tumaric esters and amides. The method of this invention for expanding the molecular weight chains of the polymers, preferably thermoplastics, is advantageous for processing or fabricating thermoplastics.

Abstract: A new class of ethynyl-terminated oligomers and the process for preparing same are disclosed. Upon the application of heat, with or without a catalyst, the ethynyl groups react to provide crosslinking and chain extension to increase the polymer use temperature and improve the polymer solvent resistance. These improved polyesters are potentially useful in packaging, magnetic tapes, capacitors, industrial belting, protective coatings, structural adhesives and composite matrices.

Abstract: This invention is an aircraft 10 with a system for increasing the lift-drag ratio over a broad range of operating conditions. The system positions the engines and nacelles 15 over the wing 12 in such a position that gains in propeller 16 efficiency is achieved simultaneously with increases in wing lift and a reduction in wing drag. Adverse structural and torsional effects on the wings 12 are avoided by fuselage mounted pylons which attach to the upper portion of the fuselage 11 aft of the wings. Similarly, pylon-wing interference is eliminated by moving the pylons to the fuselage. Further gains are achieved by locating the pylon surface area aft of the aircraft center-of-gravity, thereby augmenting both directional and longitudinal stability. This augmentation has the further effect of reducing the size, weight and drag of empennage components 13.

Abstract: Sulfone-ester polymers containing pendent ethynyl groups and a direct and multi-step process for preparing same are disclosed. The multi-step process involves the conversion of a pendent bromo group to the ethynyl group while the direct route involves reacting hydroxy-terminated sulfone oligomer or polymers with a stoichiometric amount of 5-(4-ethynylphenoxy)isophthaloyl chloride. The 5-(4-ethynylphenoxy)isophthaloyl chloride and process for preparing same are also disclosed.

Abstract: This is a device for suspending a store 66 from an aerodynamic support surface, such as an aircraft wing 12, and more specifically for improving upon single pivot decoupler pylons by reducing both frequency of active store alignment and alignment system space and power requirements. In the described embodiment, two links 36 and 42 suspend a lower pylon/rack section 60, and releasably attached store 66, from an upper pylon section 16 mounted under wing 12. Links 36 and 42 allow lower pylon section 66 to rotate in pitch about a remote pivot point 68. A leaf spring 30 connected between lower section 60 and electrical alignment system servomechanism 18 provides pitch alignment of the lower section 60/store 66 combination. Servomechanism 18 utilizes an electric servomotor 20 to drive gear train 21 and reversibly move leaf spring 30, thereby maintaining the pitch attitude of store 66 within acceptable limits. Damper 54 strokes when lower section 60 rotates to damp large oscillations of store 66.

Abstract: The disclosure relates to a deployable M-braced truss structure that is efficiently packaged into a compact stowed position and expandable to an operative position at the use site. The M-braced configuration effectively separates tension-compression and shear in the structure and permits efficient structural design. Both diagonals and longerons telescope from an M-braced base unit. They are deployed either pneumatically, mechanically by springs or cables, or by powered reciprocating mechanisms. Upon full deployment, the diagonals and longerons lock into place with a simple latch mechanism.

Abstract: An aromatic condensation polyimide film that is approximately 90% transparent at 500 nm, useful for thermal protective coatings and the like and the process for preparing same are disclosed. An essential feature of the invention for achieving maximum optical transparency films requires utilizing recrystallized and/or sublimated specific aromatic diamines and dianhydride monomers and introducing bulky electron-withdrawing groups and separator groups into the polymer molecular structure. The incorporation of bulky electron-withdrawing groups in the diamine portion of the polymer structure serves to reduce the formation of inter-chain and intra-chain charge transfer complexes which normally cause large absorptions in the UV-visible range. Incorporation of separator atoms into either the diamine or dianhydride monomers serves to reduce the amount of conjugation and inter-and intra-chain electronic interactions and thereby lessen charge transfer complex formation.

Abstract: A nebulization reflux concentrator 10 for removing trace gas contaminants from a sample gas is disclosed. Sample gas from a gas supply 40 is drawn by a suction source 42 into a vessel 11. The gas enters vessel 11 through an atomizing nozzle 16, thereby atomizing and entraining a scrubbing liquid solvent drawn through siphon tube 22 from a scrubbing liquid reservoir 21. The gas and entrained liquid rise through concentrator 10 and impinge upon a solvent-phobic filter 28, whereby purified gas exits through filter 28 and contaminated liquid coalesces on filter 28 and falls into reservoir 21.

Abstract: An aromatic condensation polyimide film that is approximately 90% transparent at 500 nm, useful for thermal protective coatings and the like, and the processes for preparing same by thermal and chemical conversion are disclosed. An essential feature of the invention for achieving maximum optical transparency films requires utilizing recrystallized and/or sublimated specific aromatic diamines and dianhydride monomers and introducing phenoxy or thiophenyl separator groups and isomeric m,m'- or o,p'-oriented diamines into the polymer molecular structure. The incorporation of these groups in the polymer structure serves to separate the chromaphoric centers and reduce the formation of inter-chain and intra-chain charge transfer complexes which normally cause absorptions in the UV-visible range.

Abstract: A column longeron latch assembly 72 provides the securing mechanism for the deployable, telescoping column 12 of a hoop/column antenna 10. Column 12 is an open lattice structure with three longerons disposed 120.degree. apart as the principle load bearing member and is deployed from a pair of eleven nested bays 22, 23 (FIG. 2) disposed on opposite sides of a center section 21 under the influence of a motor-cable-pulley system (FIGS. 3 and 4). Longeron latch 72 is a four bar linkage mechanism using the over-center principle for automatically locking the longeron sections into position during deployment and serves to unlock the sections when antenna 10 is to be re-stowed. A spring pack 61 disposed in an end of each longeron serves to absorb stress forces on the deployed column through the cam head piston and abutting latch from an adjacent longeron.

Abstract: Sulfone-ester polymers containing pendent ethynyl groups and a direct and multi-step process for preparing same are disclosed. The multi-step process involves the conversion of a pendent bromo group to the ethynyl group while the direct route involves reacting hydroxy-terminated sulfone oligomer or polymers with a stoichiometric amount of 5-(4-ethynylphenoxy)isophthaloyl chloride. The 5-(4-ethynylphenoxy)isophthaloyl chloride and process for preparing same are also disclosed.

Abstract: A joint for joining composite material such as segments of the skin 12 and 13 of an aircraft. Tapered splice plates 30 and 31 overlap the ends 14 and 15 of the skin. The thickest portion 34 of the splice plates overlap the ends 14 and 15. The splice plates are clamped together on the skin segments 12 and 13 by fasteners 50, 52, 54 and 56. The tapered splice plates are designed to minimize load transfer at the outermost bolt row 56 coincident with maximum bypass stress in the skin segments while simultaneously maximizing load transfer in both the skin segments and splice plates at the innermost bolt row 50.

Abstract: A collapsible-expandable truss structure 16 including first and second spaced surface truss layers (18, 20) having an attached core layer 22 is disclosed. The surface truss layers are composed of a plurality of linear struts 40 arranged in multiple triangular configurations with each linear strut being hinged at its center 41 and hingedly connected at each end thereof to a nodular joint 25. A passive spring 64 serves as the expansion force to move the folded struts from a stowed collapsed position to a deployed operative final truss configuration. Damper 62 controls the rate of spring 64 expansion for synchronized deployment of truss 16 as the folded configuration is released for deployment by restraint belts 72a and 73a synchronously extending under the control of motor (71) driven spools 72 and 73.

Abstract: A new class of ethynyl-terminated oligomers and the process for preparing same are disclosed. Upon the application of heat, with or without a catalyst, the ethynyl groups react to provide crosslinking and chain extension to increase the polymer use temperature and improve the polymer solvent resistance. These improved polyesters are potentially useful in packaging, magnetic tapes, capacitors, industrial belting, protective coatings, structural adhesives and composite matrices.

Abstract: Ethynyl and substituted ethynyl-terminated polysulfones and a process for preparing the same are disclosed. These polysulfones are thermally cured to induce cross-linking and chain extension, producing a polymer system with improved solvent resistance and use temperatures. Also disclosed are substituted 4-ethynylbenzoyl chlorides as precursors to the substituted ethynyl-terminated polysulfones and a process for preparing the same.