Abstract: A method and apparatus for draw forming a metal sheet over a male form to produce a three-dimensional shape. A sheet of metal is clamped between upper and lower draw plates positioned above the male form. The upper plate has an edge conforming to the male form shape. The plates and sheet are moved downwardly over the form with the edge of the upper plate firmly pressing the sheet against the form. The clamping pressure between the draw plates allows suitable slippage as drawing proceeds to produce a drawn shape of intended thickness. The drawn shape has a configuration conforming to the outer surface of the male form and has an outer surface of improved uniformity and appearance due to the wiping action of the upper plate edge.

Abstract: A pair of sheets of a metal capable of exhibiting superplasticity, such as Titanium, are placed in overlapping relationship and the peripheral edges of the sheets are joined, such as by welding, to provide a gas impervious seal. The joined metal sheets are lowered into a press so that they extend vertically between a pair of horizontally spaced apart, vertically extending preheated ceramic dies. The dies are previously transferred inside insulating shrouds from a preheater station before being loaded into the press. At least one of the dies is moved horizontally toward the other one of the dies so that the joined metal sheets are positioned closely adjacent to the dies. As a result, the metal sheets are heated to a predetermined temperature at which they are capable of exhibiting superplasticity. Thermostatically controlled heating platens behind the dies offset any heat losses in the dies as they radiate energy to the joined metal sheets.

Abstract: A ring insert for locally reinforcing a panel having a honeycomb core and at least one face sheet. The ring insert has at least two adjacent corrugated foil strips wound with the surface of the strips (and the corrugations) lying substantially perpendicular to the ring axis. The corrugations in adjacent strips have substantially different corrugation curve periods to prevent nesting of the corrugations of one strip into those of the next strip. The strips are bonded together to form a unitary ring. These inserts are adapted to be placed in cut-outs of corresponding shape in a honeycomb core and to be bonded thereto and to the panel face sheets. A method and an apparatus for winding the coil are also disclosed.

Abstract: A thrust ring assembly for use in a thrust reverser system for a gas turbine engine. The ring assembly is useful in a turbine engine having a core engine surrounded by an engine casing and nacelle, with a fan at the inlet directing air flow into the bypass duct between core engine and nacelle. The thrust reverser basically comprises at least one opening through the engine casing and nacelle, a turning vane cascade in the opening, a cover movable by an actuator between positions covering and uncovering the opening and at least one blocker door movable between a position allowing flow through the bypass duct and a position diverting flow to the turning vane cascade. The actuator and cascade are severely aerodynamically loaded during thrust reversal. The improved thrust ring assembly carriers those loads and transfers them to the engine casing. The forward ends of the cascade and actuator are secured to a bulkhead ring which is secured to the base of a frustoconical ring.

Abstract: The invention is directed a laminate structure using a reticulated adhesive material positioned between the honeycomb core and a perforate sheet and a precured reticulated adhesive between the perforated sheet and an outer layer of wire screen or other porous fibrous materials with similar pore openings therethrough through which the cells of the honeycomb core can communicate the atmosphere adjacent to the opposite side of the outer layer of porous material and a method of manufacturing same. During the manufacturing process of honeycomb noise attenuation structures which includes an imperforate sheet, an open cell honeycomb core, a perforated sheet and a layer of porous material stacked in that order a thin sheet of a reticulative adhesive material is positioned between the honeycomb core and perforated sheet and between the perforated sheet and the outer porous layer.

Abstract: A method and apparatus for superplastic forming and diffusion bonding of hollow metal parts. A forming assembly is prepared by surrounding a hollow tool (typically having a frusto-conical exterior) with a part blank having a corresponding shape, attaching parts, such as rings, to the exterior of the blank, then surrounding those parts with a skin blank. The forming assembly is placed in a pressure chamber, a heater is placed within the assembly and the chamber is sealed. The assembly of parts is heated to the diffusion bonding temperature of the parts while subjecting them to high gas pressure. The skin blank is deformed into intimate contact with the adjacent surfaces of the other parts and all of the parts are diffusion bonded together at all interfaces to form a unitary product. Gas pressure is released and the product is cooled and removed from the chamber and hollow tool. Any desired finish machining is accomplished and the productive is complete.

Abstract: A method is provided for achieving predetermined thickness requirements throughout a superplastically formed structure having extreme contours. A laminate assembly of sheets of a metal capable of exhibiting superplasticity, such as titanium alloy, is formed by a combination of superplastic forming and diffusion bonding. The shapes and positioning of the sheets is selected to provide extra metal where the greatest degree of stretching is necessary, such as around the lobes of an exhaust mixer for a turbofan aircraft engine. The gauge can thus be controlled throughout the structure while avoiding weak points and undue weight.

Abstract: An improved method of superplastic forming comprises the steps of selecting a relatively larger driver sheet and a relatively smaller part blank, both being made of Titanium, Titanium alloy or other metal capable of exhibiting superplasticity. A ceramic die is placed on a bottom wall of an upwardly opening ceramic forming chamber having sidewalls with upper edges. The ceramic chamber has an outer supporting steel jacket. The part blank is positioned over the die. The driver sheet is positioned over the part blank so that the peripheral edges of the driver sheet rest on the upper edges of the sidewalls of the forming chamber. A cover is provided for closing the chamber. It has a peripheral seal extending from an underside thereof. The cover and the chamber are clamped together in order to impinge the seal into a periphery of the driver sheet. The driver sheet and part blank are then heated to a predetermined temperature at which they exhibit superplasticity.

Abstract: The disclosure relates to a method of forming carbon-carbon composites wherein prereaction of the filler ingredients takes place prior to the prepregging operation, thereby ensuring that the sealant phase is both homogeneous and unsegregated on a microscopic scale. Composites prepared from several constituent inhibitor powders often have one inhibitor component segregated within the carbon fabric and fiber bundles during compaction, debulking and press curing. Composites prepared from prereacted powders have inhibitor constituents mixed on an atomic scale. Thus, the oxide sealant which forms from the prereacted particulate filler has an optimized composition with all of the desirable qualities, such as level viscosity, good wetting, low water solubility, low reactivity with the carbon fibers and carbon matrix during graphitization and low reactivity with the chemically vapor deposited coating.

Abstract: A high strength, light weight stabilized skin structure having spaced skin sheets and a plurality of hollow metal spheres filling the space between the skins. The spheres and skins are bonded together, resulting in a unitary structure. The spheres typically have outside diameters of from about 0.005 to 0.5 inch, with tall thicknesses of about 0.0005 to 0.005 inch. Spheres of different sizes may be used, with smaller or heavier wall thickness spheres in high load areas, such as insert attachment points, and larger spheres in lightly loaded areas. The spheres preferably have a surface coating of a brazing material and are bonded together and to the skins by furnace brazing.

Abstract: An oxygen resistant high temperature composite structure comprises a carbonous matrix and reinforcing high temperature fibers disposed within said matrix, an outer refractory coating covering said matrix, boron, in elemental form and/or as a moiety of a compound dispersed throughout said structure, silicon, in elemental form and/or as a moiety of a compound dispersed throughout said structure, and titanium, in elemental form and/or as a moiety of a compound dispersed throughout said structure, said silicon and said boron oxidizing when exposed to a high temperature, oxidizing environment to form silicon oxide and boron oxide, and said titanium forming titanium oxide which stabilizes the molten phase of the boron oxide. Microcracks which form in the refractory coating are sealed by a molten glass which forms from oxidation of the boron, silicon and titanium, thereby preventing oxidation degradation of the underlying matrix.

Abstract: A method and apparatus for forming and bonding metal assemblies using an internally heated chamber. The parts can be both superplastic formed and diffusion bonded to other parts. A closable chamber contains a heating element near the chamber center. A ceramic die at least partially surrounding the heating element has a forming surface toward the heating element. The inner wall of the chamber is lined with a pressure bladder. A granular material, conical ceramic support, or extensible bladder fills the space between ceramic die and chamber inner wall. With the chamber closed, the heater is activated while an inert gas under pressure is introduced between heater and die and the bladder if used is pressurized. The bladder or packed granules support the outer die surface while the gas pressure presses metal parts on the die forming surface against the die. The metal parts are formed and bonded together by the substantially isostatic forces thereon.

Abstract: A filament winding payoff unit and process for applying strands of adhesive impregnated filament material arranged into a gap-free band to a rotating mandrel. A plurality of side-by-side slightly overlapped impregnated filament strands are passed over bars between tines of combs for positioning when leaving the payoff head. The payoff head is positionable toward and away from the rotating mandrel to allow for mandrel longitudinal dimension changes while maintaining the payoff head roller in contact with the mandrel at a predetermined pressure thereagainst. The payoff head is also freely pivotable horizontally to maintain a proper angle of filament application to any changing mandrel longitudinal configuration.

Abstract: A method of diffusion brazing two or more titanium alloy metal parts, such as sheets, thick sections or a honeycomb core to one or two face sheets, to form a unitary panel. A low melting copper-nickel layer is interposed between the faying surfaces of two parts to be bonded. The layer may be a foil placed between the surfaces or may be a layer plated onto one or both surfaces. The assembly is heated to at least the eutectic melting temperature of the base metal-interlayer eutectic point for a time sufficient to permit effective wetting and diffusion bonding of the surfaces. The assembly is held at the elevated temperature a sufficient additional time so as to allow isothermal solidification to occur. The assembly is then cooled, resulting in a unitary structure. This method is particularly effective with titanium aluminides face sheets and a titanium aluminide or other titanium base honeycomb core and with an interlayer consisting essentially of nickel and copper.

Abstract: An electronic indicator comprising a first portion attached at one end to an object to be controllably stretched or elongated and a second portion slideably connected to the first portion for relative movement therewith and connected at one end remote from the object attachment of the first portion. Electrical connections donating relative movement between the two indicator portions are attached to monitoring equipment to indicate stretch length.

Abstract: The invention is directed to an improved hopper for feeding abrasive material of very small grit size to a cutting head. The device comprises an open hopper vertically disposed with a transverse positioned pick-up tube located in the lower portion of the hopper. The pick-up tube has a tubular center with a necked down diameter intermediate of its's ends. An opening extends from the bottom of the tube into the tubular center at a location centered in the necked down portion thereof. One end of the tube is vented to atmosphere through an adjustable orifice and the other end is connected to a source of low pressure created within the mixing chamber of the nozzle body assembly by high pressure water passing across the open end of the tube. This effect causes abrasive grit to be drawn through the opening in the bottom of the tube out the low pressure end of the tube to the cutting head.

Abstract: A filament winding payoff head unit and process for applying strands of adhesive impregnated filament material arranged into a gap-free band to a rotating mandrel. A plurality of side-by-side slightly overlapped impregnated filament strands are passed over bars between tines of combs for positioning when leaving the payoff head. The payoff head is positionable toward and away from the rotating mandrel to allow for mandrel longitudinal dimension changes while maintaining the payoff head roller in contact with the mandrel at a predetermined pressure thereagainst. The payoff head is also freely pivotable horizontally to maintain a proper angle of filament application to any changing mandrel longitudinal configuration.

Abstract: A method of producing a reinforced duct structure for use with turbo-fan aircraft engines and the like. The duct is first cut from a flat metal sheet in a predetermined pattern. The sheet is rolled to form a tubular or conic structure of the approximate desired configuration and welded along the open seam. The welded tubular structure is then expanded to the exact required shape. The expanded tubular structure is cut out in selected areas to form a tubular grid structure. A tubular liner conforming to the inner surface of the tubular grid structure is installed and bonded to the grid structure forming an integral tubular structure of the desired configuration and strength and; attachment of any required mating flanges and structure bosses to the integral tubular structure.

Abstract: A method of laminating a porous overlay material to a perforated plate with a dry film adhesive which does not block perforations or pores in the two components. A lay-up is preferably prepared by assembling in order on a vacuum platen a porous peel ply sheet, a sheet of dry film adhesive, a perforated plate, a sheet of microporous material to be bonded to the perforated plate and an air permeable sheet. A vacuum is drawn through holes in the vacuum platen contiguous to the bottom surface of the porous peel ply sheet while the assembly is heated to the softening temperature of the adhesive film. The vacuum is directly applied through the perforation, drawing the film down through the perforations and into contact with the peel ply sheet. As heating continues the film softens sufficiently to adhesively bond the microporous material to the perforated sheet.

Abstract: A cascade assembly for directing the gases externally of a jet aircraft engine in a forwardly direction when the engine is in a gas reversing mode. The cascade assembly comprises a plurality of cascade panel sections positioned in a side by side relationship over an opening in the engine nacelle. The panel sections have a plurality of spaced apart curvilinear vanes angled from the centerline of the engine. Longitudinal beams are positioned over the longitudinal edges and adjacent ends of at least one cascade panel section to secure it in place. The beam is "T" configured in the cross-section with feet or pads on each end to overlay the longitudinal outer edge and adjacent end surfaces of the cascade panel section or sections which it is securing in place. The pads or feet on the beam ends include apertures therethrough for securing the beams to aircraft structure. Both the cascade panel sections and beams are constructed of molded plastic or cured composite materials.