Abstract: A process for producing a green composite structure by isostatic compression and filtration. A suspension of colloidal size matrix powders is established in a carrier liquid. The suspension is incorporated into a die chamber having a filter opening containing a filter which is permeable to filtrate from the suspension under applied pressure but substantially impermeable to the matrix powders. An elevated pressure is isostatically imposed on the colloidal suspension within the die chamber. The pressure is maintained for a period of time to expel at least 20% of the liquid originally in the colloidal suspension through the filter opening. A specific die chamber comprises a rigid cage structure and an expandable bladder within the cage structure into which the colloidal suspension is introduced. The cage structure is disposed within a pressure vessel which can be initially evacuated to cause the bladder to conform to the cage structure and then pressurized with fluid for the isostatic compression procedure.

Abstract: A portable grip length indicator for determining a discrete fastener length for a fastener to be used in fastening a stack of two or more pieces of material. The indicator comprises a body, a probe attached to the body and capable of extending beyond the body for determining the thickness of the stack, a transducer connected to the probe for sensing the relative movement of the probe and translating the movement into an electrical output signal, and an electrical processor for computing the discrete fastener length from the output signal of the transducer according to a predetermined correlation of the thickness of the stack and the type of fastener to be used.

Abstract: A material transfer system is provided having particular utility in cooperation with a liquid jet abrasive cutting system in which a continuous supply of abrasive, particulate material is required for abrasive cutting operations. Primary and secondary hoppers are provided for containing the abrasive particulate material, and the secondary hopper is suitably located at a position adjacent to the work station and remote from the primary hopper. The secondary hopper is provided with a first chamber and a second, lower chamber positioned beneath the first chamber.

Abstract: A system for closely controlling the standoff distance of a nozzle in a remotely controlled fluid jet abrasive cutting system. The system comprises a head assembly having a support section and a nozzle body. Control means move the head assembly along a desired cutting path relative to the workpiece. A nozzle is mounted in the nozzle body and oriented to dispense cutting fluid along an axis directed against the workpiece. The nozzle body and the support section are interconnected by means which function to bias the nozzle body relative to the mounting section in a direction along the cutting axis of the nozzle. The nozzle body is provided with a standoff member which is adapted to ride on a portion of the workpiece and which projects beyond the nozzle tip by a distance sufficient to hold the nozzle off of the workpiece by the desired standoff distance.

Abstract: A process for the production of reinforced refractory composite structures which may be of high density and shaped in desired three dimensional configurations. The shaped composite structures are produced by forming a suspension of particulate materials including a colloidal refractory power, colloidal sintering aid, and refractory reinforcement whiskers in a carrier liquid. The colloidal suspension is conformed to a desired configuration and brought into contact with a semipermeable membrane. A pressure is imposed on the suspension in the desired configuration to expel liquid from the suspension through the membrane to arrive at a green composite having a density of at least 40% of theoretical density. After drying, the green composite is then sintered under conditions to form an intergranular liquid phase in the composite providing further densification. A specific composite is a silicon carbide reinforced silicon nitride composite.

Abstract: An apparatus for translating motive energy includes a rotor structure, having mutually spaced rotor members, adapted to react with fluids within the housing. In one embodiment, the rotor structure is rotationally driven by an external power plant for pumping fluids through a tangentially oriented outlet duct. In a second embodiment, the apparatus is driven by fluid under pressure which is conducted toward the rotor structure through an inlet aligned with peripheral portions of the rotor members, for rotationally driving the rotor structure. A variable geometry inlet control system is provided for controlling fluid flow in response to varying flow conditions and for directioning fluid flow to a portion of the rotor structure. The apparatus incorporates a structural configuration which permits its construction of carbonized composite materials, for operation at elevated temperatures.

Abstract: A temperature sensitive data storage element is disclosed, suitable for application in an erasable optical read/write data storage system. The data storage element includes an optical tuning film and a film of thermochromic phase change material which will change from a first phase to a second phase at temperatures in excess of an upper temperature and back to the first phase at temperatures below a lower temperature. In one application, a thermally controlled support member may be employed to temporarily lower the temperature on the storage element to a point below the lower temperature, thereby initializing the element. In one embodiment, the storage element is a planar, suitably circular disk. In use, the storage element is adapted to be initialized by a modulated laser beam which may be focused on the storage element to temporarily heat particular portions of the element to a temperature in excess of the upper temperature, causing a phase change.

Abstract: An apparatus is disclosed for forming elongate structures of composite materials. The apparatus includes a plurality of forming dies for preheating, heating and then cooling an elongate portion of composite material while shaping the material within an internal passage. A pulling device is utilized to continuously draw elongate strips of composite material through the forming dies. The pulling device includes two opposed endless track devices. One of the endless track devices serves to mount a plurality of engagement dogs, each having a substantially flat surface for engagement of the elongate portion of composite material. The other endless track device serves to mount a plurality of pivoting engagement dogs, each having a curvilinear surface wherein increased resistance by said elongate strip of composite material will pivot the curved surface into closer alignment with a corresponding flat surface, thereby tightening the grip of the pulling device on the elongate strip of composite material.

Abstract: A radiographic image is formed of a workpiece irradiated by neutron or X-ray energy. A radiophosphorescent screen is positioned adjacent the workpiece to form a scintillation pattern. The radiation may consist of thermal neutrons radiation from which gamma radiation has been substantially removed. The image is stored upon the semi-conductor target of a television camera.

Abstract: An erasable optical read/write data storage system is disclosed. The data storage system utilizes a temperature sensitive data storage disk which includes an optical tuning film and a film of thermochromic phase change material which will change from a first phase to a second phase at temperatures in excess of an upper temperature and back to the first phase at temperatures below a lower temperature. An environmentally controlled chamber is provided to maintain the data storage disk at a selected bias temperature between the lower and upper temperatures to ensure that no unintentional phase change will occur. A thermally controlled support member is utilized to temporarily lower the temperature of the disk to a point below the lower temperature, thereby initializing the disk. A modulated laser beam is then focused on the disk to temporarily heat particular portions of the disk to a temperature in excess of the upper temperature, causing a phase change.

Abstract: In a method of installing a septum (18) at a desired depth within a section of honeycomb core (12) for use in a sound attenuation panels, the septum is sandwiched between two layers (20, 24) of support material having a melting temperature intermediate between the fusing and curing temperatures of the septum material. The honeycomb core (12) is pressed into supporting materials and septum to segment and position the septum (18) therein, after which the resultant assembly is heated sufficiently to allow the septum to fuse and adhere to the honeycomb core. The resultant assembly is then heated sufficiently to melt the support material and allow it to be drained away, leaving the segmented septum (18) in place within the honeycomb core.

Abstract: A pressure sensitive film display is disclosed having a piezoelectric substrate and a thin film of pressure sensitive phase change material disposed thereon. A film of pressure sensitive material such as samarium sulfide is deposited on a piezoelectric substrate and exhibits a marked increase in reflectance at a region thereof subjected to a pressure in excess of a selected threshold pressure. Three interdigital surface acoustic wave transducers are provided along three edges of the display and are utilized to produce selective surface acoustic wave pulses in the surface of the film. Each surface acoustic wave pulse generates an area of pressure such that an external pressure greater than the selected threshold pressure is generated only at each point where three surface acoustic wave pulses intersect.

Abstract: An apparatus is disclosed for forming concave tape wrapped composite structures. The apparatus utilizes a mold having a cylindrical concave surface with a mounting plate mounted for rotation at each end thereof about a point on a longitudinal axis of the concave surface. A longitudinal shaft is mounted to each mounting plate a selected distance from the longitudinal axis and extends parallel thereto. A tape dispenser carriage is mounted to the longitudinal shaft and is movable along the length thereof. A radial shaft is mounted through the tape dispenser carriage such that the longitudinal axis of the radial shaft passes through the longitudinal axis of the concave surface and along a radius of the concave surface.

Abstract: Disclosed is a method of making carbon/carbon composites by pyrolytic conversion of a carbonizable liquid in a pre-formed graphite body to form an amorphous carbon reinforcing matrix. Graphite fabric saturated with a carbonizable liquid is formed into the shape of the desired end product body and placed in a flexible bag. The bag is evacuated to compress the formed body and the bagged body subjected to external pressure and heated. When the carbonizable liquid is heated to the curing temperature, the external pressure is reduced, causing volatile materials in the liquid to expand and form an interconnected pore structure. The formed body is thereafter heated to a temperature in excess of the curing temperature to further remove volatile materials therefrom. The cured rigid body is then transferred to a pyrolyzing furnace and rapidly heated in an inert gaseous environment directly to about 1500.degree. F. to pyrolyze the carbonizable material and form an amorphous carbon matrix.

Abstract: A composite material manufacturing process and resulting structure is provided to include high strength material whiskers (20) having a characteristic orientation when placed in an electromagnetic field (22). In one embodiment, whiskers (20) are disposed between lamina (10 and 15) and oriented generally perpendicular to the fiber layers (14 and 18). The whisker (20) orientation is maintained during a curing cycle for the respective matrices (12 and 16) wherein the matrix viscosity allows the whiskers (20) to orient in response to the applied electromagnetic field (22). The whiskers (20) retain their orientation in the resulting laminate to provide improved structural integrity for the laminate.

Abstract: A structure capable of being expanded and retracted. The structure includes a pair of cells each including a plurality of leg elements which are pivotally joined at one end to form an apex point and which are pivotally joined at their opposite ends from the apex point connection to the corresponding leg element from the other cell to form a plurality of common base points. The structure also includes a plurality of hinged elements connected between adjacent common base points to thereby form a common base and the hinged elements each have a pair of sections that are connected at a hinge point approximately midway between the adjacent common base points to which the other end of each section is connected.

Abstract: A dynamic infrared scene projector for presenting cinematic, two-dimensional, spatially distributed scene data to an infrared sensor is provided comprising programmable, thermoptic infrared modulators which exploit thermally-induced changes in the infrared optical properties of a thin film of vanadium dioxide. Because of a hysteresis in the vanadium dioxide material, a stored scene can be created in the modulators by scanning a focused modulated visible or near-infrared laser beam across the thin film while it is thermally biased in the hysteresis loop. The scene is projected into the sensor by placing the modulators between an infrared source/condenser system and a system of projection optics. Dynamic scene projection is accomplished by an erase/rebias system and an optical framing switch to yield a flicker-free output. Erasing of the optical modulator is accomplished by momentarily cooling the VO.sub.2 film to a temperature below the hysteretic loop.

Abstract: In an optical radar system a coherent signal is transmitted at a variable position and the return signal, that is, the reflected portion of the coherent signal is received and coherently detected. The transmitter utilizes a scanning laser having an electron beam that impinges upon a variable reflectance mirror that terminates one end of an optical cavity. An oscillating mode is generated within the resonant cavity when the electron beam locally heats the surface of the variable reflectance mirror to create a pixel that reflects light in a diffracted pattern. The receiver utilizes a stable single mode laser to illuminate a variable reflectance surface. A receiver electron beam generates a plurality of receiver pixels at various positions. The diffracted light from each pixel generates a plurality of variable angle local oscillator beams that are summed with the return signal at a beamsplitter. The output of the beamsplitter is applied to the surface of a detector array.

Abstract: An optical processing system for processing infrared information prior to detection. In one embodiment, optical information from an infrared scene is focused by optics (10) onto a thermoptic modulator (12) which contains an optical structure (16) disposed on the faceplace of a cathode ray tube. The modulator is normally nonreflective of infrared energy from the scene incident thereon. Reflecting spots (22) written on the modulator by an electron beam reflect a portion of the scene to a detector (52) which generates a signal representative of the radiance of the scene element sampled. A series of first and second reflecting spots of different size are written at selected coordinates on the modulator. The respective signals generated by the detector for each spot of the pair are subtracted to provide a spatial band pass filtered signal for each sampling coordinate on the modulator.

Abstract: An actuator (10) for effecting relative pivotal movement between two structures (12, 14) includes a bent beam member (18) having a first portion (20) rotatably secured to one structure and a second portion (22) supported for rotation and eccentric revolution by a housing (42) grounded to the other structure. Index gears (64, 66) assure eccentric revolution of the beam member (18) in an opposite direction in response to rotation of the bent beam member to produce relative pivotal movement between the structures (12, 14). In the first two embodiments, the actuators (10, 120) incorporate internal hydraulic or electric drive arrangements. In other embodiments, the actuators (150, 172, 250, 270) employ various planetary type gear arrangements to achieve even greater mechanical advantage. In the last embodiment, both portions (304, 306) of the bent beam member (302) of the actuator (300) are driven and supported for eccentric revolution.