Abstract: Imide-linked bisphthalonitrile compounds are prepared by combining a dicyano aromatic diamine and an organic dianhydride to produce an amic acid linked bisphthalonitrile copound. The amic acid linked bisphthalonitrile compound is dehydrocyclized to produce the imide-linked bisphthalonitrile compounds. The imide-linked bisphthalonitrile compounds may be polymerized to produce a phthalocyanine polymer by heating the imide-linked bisphthalonitrile compound, either alone or in the presence of a metal powder or a metal salt. These compounds are useful in the coating, laminating and molding arts. The polymers are useful in composite matrix resins where increased fire resistance, toughness and resistance to moisture are required, particularly as secondary structures in aircraft and spacecraft.

Abstract: Vinyl pyridines including vinyl stilbazole materials and vinyl styrylpyridine oligomer materials are disclosed. These vinylpyridines form copolymers with bismaleimides which copolymers have good fire retardancy and decreased brittleness. The cure temperatures of the copolymers and substantially below the cure temperatures of the bismaleimides alone. Reinforced composites made from the cured copolymers are disclosed as well.

Abstract: A personnel emergency carrier vehicle is disclosed which includes a vehicle frame (10) supported on steerable front wheels (20, 22) and driven rear wheels (36, 38). A supply (78) of breathing air is connected to quick connect face mask couplings (112, 114) and umbilical cord couplings (116, 118) for supplying breathing air to an injured worker or attendant either with or without a self-contained atomspheric protection suit for protection against hazardous gases at an accident site. A non-sparking hydraulic motor (90) is utilized to drive the vehicle and suitable direction (134) and throttling controls (138, 134) are provided for controlling the delivery of a hydraulic driving fluid from a pressurized hydraulic fluid accumulator (100). A steering axis (80) is steerable through a handle (82) to steer the front wheels (20, 22) through a linkage assembly (84, 28, 30).

Abstract: The invention embodies a system and procedure for independently determining the surface emissivity of a mesh membrane material 12. The system is a closed one with respect to unwanted or uncorrected radiation outside the system and is composed of a radiometer 11 connected to a horn antenna 13, a test section 15 sealed to the horn antenna 13 and a cryogenically cooled matched load 17 exposed to the interior of the system. The material 12 is enclosed in a convection test chamber 14 within test section 15, heated within test chamber 14 and allowed to radiate within the system such that a component of the radiation energy of material 12 is measured by the radiometer 11 in terms of brightness temperature. The matched load 17 serves as the stabilizing source of uncorrelated radiation within the system by radiating within the system at a constant cryogenic temperature. The actual physical temperature of the material 12 is also measured during the heating process.

Abstract: An elevated waterproof access floor system having subfloor channels or compartments for power lines, gas lines or the like is adapted such that it can be opened and subsequently resealed without destroying the waterproofing and without destroying its aesthetic appearance. A multiplicity of tiles are supported on a support grid, and a flooring sheet is supported on the tiles. Attachment means are provided to prevent lateral but non vertical movement of the flooring sheet with respect to the tiles so that the flooring sheet can be lifted off the tiles, but when the flooring sheet is supported on the tiles, no lateral slipping will occur. The flooring sheet is made of a heat resealable material, so that it can be cut away in sections, and the tiles therebelow lifted off, to provide access to subfloor compartments. The heat-resealable flooring sheet can be resealed after penetration, to yield flooring system in which waterproofing and aesthetic appearance are maintained even after penetration.

Abstract: 4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g. hexakis amino or trisaminophenoxy-trisphenoxy-cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yeilds and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.

Abstract: A laser Doppler velocimeter (LDV) system (10) has a laser (12), a waist position adjusting lens (13), and a beam splitter (15), which direct laser beams (14) parallel to optical axis (16) of negative lens (18). Negative lens (18) is fixed relative to afocal lens pair (24,26). A pair of planar mirrors (20, 22) intersect at right angles and respectively intersect optical axis (16) and optical axis (28) of the afocal lens pair. Mirrors (20, 22) are movable along optical axis (28) toward and away from afocal lens pair (24, 26) to focus laser beams (14) in focus area (30) while maintaining a constant beam waist, crossing angle and intersection with other laser beams to produce a constant sensitive volume as the focus is changed.

Abstract: Vinyl pyridines including vinyl stilbazole materials and vinyl styrylpyridine oligomer materials are disclosed. These vinylpyridines form copolymers with bismaleimides which copolymers have good fire retardancy and decreased brittleness. The cure temperatures of the copolymers are substantially below the cure temperatures of the bismaleimides alone. Reinforced composites made from the cured copolymers are disclosed as well.

Abstract: Siloxane-containing addition polyimides having improved physical property characteristics of flexibility, drape, tack and toughness and the process for preparing and utilizing same are disclosed.

Abstract: A double reference pulse phase locked loop for measuring the phase shift between tone burst signals initially derived from the same periodic signal source (voltage controlled oscillator 16) and delayed by different amounts because of two different paths. A first path is from transducer 12 to surface 14 of sample 11 and back, and a second path is from transducer 12 to surface 15 and back. A first pulse phase locked loop including phase detector 26 and phase shifter 22 forces the tone burst signals delayed by the second path in phase quadrature with the periodic signal source. A second pulse phase locked loop including phase detector 21 forces the tone burst signals delayed by the first path into phase quadrature with the phase shifted periodic signal source.

Abstract: When vinyl pyridines including vinyl stilbazole materials and vinyl styrylpyridine oligomer materials are admixed with bismaleimides and cured to form copolymers the cure temperatures of the copolymers are substantially below the cure temperatures of the bismaleimides alone.

Abstract: An apparatus (10) for aligning and calibrating scene displays in an aircraft simulator (12) has a base (18) on which all of the instruments for the aligning and calibrating are mounted. Laser (26) directs beam (28) at double right prism (34) which is attached to pivoting support (36) on base (18). The pivot point of prism (34) is located at the design eye point (DEP) of simulator (12) during the aligning and calibrating. Objective lens (60) in base (62) is movable on track (64) to follow laser beam (28) at different angles within the field of vision at the DEP. An eyepiece (50) and a precision diopter (56) are movable into position behind the prism (34) during the scene evaluation. A photometer or illuminometer (70) is pivotable about pivot (74) into and out of position behind the eyepiece (50).

Abstract: 1-[(Diorganooxyphosphonyl)methyl]2,4- and -2,6-diamino benzenes are reacted with polyacylhalides and optionally comonomers to produce polyamides which have desirable heat and fire resistance properties. These polymers are used to form fibers and fabrics where fire and flame resistance properties are important, e.g., aircraft equipment and structures.

Abstract: Novel amine terminated bisaspartimides, especially 4,4'-bis{N.sup.2 -[4-(4-aminophenoxy)phenyl]aspartimido} diphenylmethane are prepared by a Michael-type reaction of an aromatic bismaleimide and an aromatic diamine in an aprotic solvent. These bisaspartimides are thermally polymerized to yield tough, resinous polymers cross-linked through --NH-- groups. Such polymers are useful in applications requiring materials with resistance to change at elevated temperatures, e.g., as lightweight laminates with graphite cloth, molding material prepregs, adhesives and insulating material.

Abstract: A method and apparatus for calibrating laser Doppler velocimeters having one or more intersecting beam pairs. These velocimeters measure fluid velocity by observing the light scattered by particles in the fluid stream. Moving fluid particulates are simulated by fine taut wires that are radially mounted on a disk that is rotated at a known velocity. The laser beam intersection locus is first aimed at the very center of the disk and then the disk is translated so that the locus is swept by the rotating wires. The radial distance traversed is precisely measured so that the velocity of the wires (pseudo particles) may be calculated.

Abstract: For use in hard space suits and the like, a joint between the torso covering and the upper arm covering (i.e., shoulder) or between the torso covering and upper leg covering (i.e., hip) is disclosed. Each joint has an outer covering and a inner covering. The outer covering has plural preferably truncated toroidal sections decreasing in size proceeding outwardly. In one embodiment at each joint there are two bearings, the first larger than the second. The outer race of the larger bearing is attached to the outer edge of the smaller end of each section and the inner race of the larger bearing is attached to the end wall. The inner race of the smaller bearing is attached to the end wall. The outer race of the smaller bearing is attached to the larger end of the next section. Each bearing has appropriate seals. Between each section is a rubber ring for the comfort of the wearer. Such rubber rings have radial flanges attached to the inner races of two adjacent bearings.

Abstract: An elbow or knee joint for a hard space suit or similar usage is formed of three serially-connected rigid sections which have truncated spherical configurations. The ends of each section form solid geometric angles, and the sections are interconnected by hermetically-sealed ball bearings. The outer two sections are fixed together for rotation in a direction opposite to rotation of the center section. A preferred means to make the outer sections track each other in rotation comprises a rotatable continuous bead chain which engages sockets circumferentially spaced on the facing sides of the outer races of the bearings. The joint has a single pivot point and the bearing axes are always contained in a single plane for any articulation of the joint. Thus flexure of the joint simulates the coplanar flexure of the knee or elbow and is not susceptible to lockup.

Abstract: Composite structures having a honeycomb core and characterized by lightweight and excellent fire resistance are provided. These sandwich structures employ facesheets made up of bismaleimide-vinyl styrylpyridine copolymers with fiber reinforcement such as carbon fiber reinforcement. In preferred embodiments the facesheets are over-layered with a decorative film. The properties of these composites make them attractive materials of construction for aircraft and spacecraft.

Abstract: For use in hard space units and the like, shoulder and hip joints comprising three serially-connected truncated spherical sections, the ends of which converge. Ball bearings between the sections permit relative rotation. The proximal end of the first section is connected to the torso covering by a ball bearing and the distal end of the outermost section is connected to the elbow or thigh covering by a ball bearing. The sections are equi-angular and this alleviates lockup, the condition where the distal end of the joint leaves the plane in which the user is attempting to flex. The axes of rotation of the bearings and the bearing mid-planes are arranged to intersect in a particular manner that provides the joint with a minimum envelope. In one embodiment, the races of the bearing between the innermost section and the second section is partially within the inner race of the bearing between the torso and the innermost spherical section further to reduce bulk.

Abstract: A hard suit for use in space or diving applications having an adjustable length torso covering that will fit a large variety of wearers. The torso covering comprises an upper section and a lower section which interconnect so that the covering will fit wearers with short torsos. One or more sizing rings may be inserted between the upper and lower sections to accommodate larger torso sizes as required. Since access of the astronaut to the torso covering is preferably through an opening in the back of the upper section (which is closed off by the backpack), the rings slant upward-forward from the lower edge of the opening. The lower edge of the upper covering section has a coupler which slants upward-forward from the lower edge of the back opening. The lower torso section has a similarly slanted coupler which may interfit with the upper section coupler to accommodate the smallest torso size.