Abstract: A support system for the aft end of fan jet gas turbine engines which reduces engine bending in operation while accommodating radial and longitudinal thermal expansion forces. A plurality of inwardly extending small flanges are provided on a first ring, which may form part of the engine core cowl, that is secured to the pylon supporting the overall engine. A plurality of outwardly extending small flanges are provided on a second ring, which is secured to, or otherwise forms a part of, the engine. These flanges are spaced in adjacent pairs, one on each ring. Torque links are connected between these pairs of flanges. The torque links support the engine aft end against bending and flexing forces while accommodating thermal expansion forces.

Abstract: A sheet of Ti 6-2-2-2-2 alloy having a starting thickness of between approximately 0.040 inches and 0.187 inches is thermomechanically treated at a temperature of between approximately 1500 degrees F. and 1750 degrees F. at a mechanical strain rate in the range of between approximately 1.times.10.sup.-4 and 1.times.10.sup.-2 inch per inch per second to produce a formed part having a tensile strength which is approximately 33% greater than untreated rolled Ti 6-2-2-2-2 alloy sheet or plate.

Abstract: A vertically reciprocable lower chamber has a ceramic forming chamber surrounded by a steel reinforcing jacket. A fixed upper chamber includes a metal cover surrounded by ceramic insulator blocks and and an outer steel jacket. A horizontal foam ceramic platen inside the steel cover has a serpentine radiant heating coil attached to the flat underside thereof via inserted fasteners for more efficient heating of a metal sheet positioned horizontally between the upper and lower chambers. A plurality of foam ceramic insulator blocks have secondary heating coils attached to their inwardly facing surfaces for heating the peripheral edges of the metal sheet. This ensures a gas tight seal between the metal cover and the sheet.

Abstract: An SPF press is capable of forming large generally cylindrical structures from a sheet made of a first metal such as Titanium. The sheet is first rolled into a cylindrical or conical part blank. The press has a generally cylindrical ceramic die with a surface defining the contour of a part to be formed. The part is formed by pressing a first side of the part blank against the die utilizing high pressure gas. Generally cylindrical gas impervious seals overlie the opposite ends of the cylindrical part blank on a second side thereof opposite the first side. Each of these gas impervious seals includes a support member and a seal member which are spaced apart to define a gap therebetween. A generally cylindrical seal ring is seated in each gap and contacts the second side of the cylindrical part blank. The seal rings are made of a second metal that is softened at a temperature at which the first metal becomes superplastic.

Abstract: A thrust reverser system for fan jet type aircraft gas turbine engines using a rack and pinion arrangement for moving blocker doors between the stowed and deployed positions. Blocker doors fill a plurality of circumferentially arranged openings.

Abstract: A method and apparatus for superplastic and diffusion bonding of hollow metal parts which are generally surfaces of rotation. A hollow frangible ceramic die having an interior shaping surface is provided. A metal part to be shaped is placed against the shaping surface (together with any other metal components to be diffusion bonded to the part during forming) and the remainder of the die is covered with sheet metal pieces, all of which are sealed together and to the part to form a gas-tight enclosure for the die. The enclosure is flushed with an inert gas and/or evacuated through an opening in the enclosure. The assembly is placed in an autoclave and exposed to an appropriate pressure and temperature to superplastic form the part outwardly against the shaping surface. The assembly is cooled and removed from the autoclave, then the enclosure is removed. The die is broken away, freeing the formed part.

Abstract: A method and apparatus for bonding high temperature structures, such as face sheets to high performance honeycomb cores, using differential gas pressure at high temperatures. A high temperature resistant, foil sheet having a thickness of from about 0.0005 to 0.003 inch is welded to a support to form a vacuum bag to surround the structure to be bonded. A vacuum line is connected to the bag to allow evacuation of the bag. Typically, the structure is bonded in a vacuum furnace. Initially, the furnace is heated to the bonding temperature of the assembly while both the furnace chamber and the vacuum bag are substantially completely evacuated. Then slight pressure is allowed to return to the chamber to force the foil sheet into intimate presure contact with the structural assembly to bring the components tightly together, using the relative pressure different between the vacuum in the chamber and the vacuum within the bag.

Abstract: A thrust reverser system for fan jet type aircraft gas turbine engines using a "sliding hinge" arrangement for moving blocker doors between the stowed and deployed positions. Blocker doors fill a plurality of radially arranged openings in an engine nacelle near the aft end of the nacelle. In the stowed position, each blocker door forms and inner and outer streamlined surface corresponding to the nacelle walls, with no actuator mechanisms extending into the air flow stream within the nacelle. Each blocker door is moved to the deployed position by an extensible rod, such as a hydraulic piston rod, extending between the nacelle near the forward edge of the opening and the approximate centerline of the door. As the door begins to move rearwardly, slider pins on the door edges slide along tracks on the adjacent nacelle islands between adjacent openings.

Abstract: A support system for the aft end of fan jet gas turbine engines which reduces engine bending in operation while accommodating radial and longitudinal thermal expension forces. A first radial ring secured to the engine structure core cowl and the overall engine support pylon has a plurality of spaced longitudinal grooves. A second, cooperating radial ring secured to the engine has a plurality of outwardly extending tabs sized to fit within the first ring grooves. The tabs do not extend fully into the grooves at ambient temperatures. When operation of the engine begins, the engine heats up to a relatively high temperature. Radial thermal expansion is accommodated by expansion of the inner ring, causing the tabs to move deeper into the grooves. Longitudinal thermal expansion is accommodated by slippage of the tabs along the grooves in a longitudinal direction. Meanwhile, the engine is supported against bending and flexing beyond the amount permitted by the space between tab ends and bottoms of the grooves.

Abstract: A composite structure for aircraft having features making it resistant to structural damage when subjected to lightning strikes. Fiber tow is wound over a rotating shaping surface which is a surface of revolution. Spaced bands of tow are laid down in a helical pattern with varying spaces between bands. Some bands are typically wound at an angle of about +45.degree.. By selectively winding in one direction and then the other, a "basketweave" pattern is obtained. Typically, the tow consists of high strength fibers in a thermosetting or thermoplastic resin matrix wound to a four layer thickness. When cured, the structure has high strength and low weight and is excellent for structures such as aircraft engine cowls. The basketweave pattern gives excellent resistance to peeling and delamination upon being struck by lightning, the types of damage which are likely to occur with the usual hoop or other continuous windings.

Abstract: A thrust reverser for aircraft fan jet engines using a plurality of sets of deflector and blocker doors filling openings through the engine nacelle during normal engine operation. During thrust reversal, the doors substantially block air normal fan air flow through the duct between engine cowling and the outer nacelle and deflect it out through the nacelle openings in a reverse direction. An actuator and hinge assembly moves each blocker door from a stowed position flush with the inner nacelle surface to a deployed position blocking air flow between nacelle and cowl. Simultaneously, an actuator and hinge assembly moves each deflector door from a stowed position flush with the outer nacelle surface to a deployed position receiving air from the blocker doors and deflecting that air flow in an outwardly and forwardly direction. The actuator and hinge assemblies are substantially out of the path of air flow in both the stowed and deployed positions.

Abstract: A pivot door type aircraft turbine engine thrust reverser which includes a pair of pivoting panels on the inner side of the door. The panels are positioned alongside the door actuation mechanism. The panels form a flush surface along the fan duct flow path when stowed during normal engine operation in flight. When the door is deployed in thrust reversing mode, one end of the door moves to at least partially block airflow through the duct and divert it out along the door through an opening uncovered by door deployment. During door deployment, a linkage moves the panels toward the outer surface of the door, exposing a door deflector plate to the airflow. Air flows along the door, then along the panel, out through the opening, then impacts the deflector plate which deflects the airflow in the reverse direction.

Abstract: An engine shroud with integral honeycomb panel corners for use in the thrust reverser region of ducted fan gas turbine engines. The integral shroud 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 engine nacelle. The shroud basically consists of right and left ducts each having an approximately semicircular cross-section with radial flanges extending from the duct edges. The flanges permit the halves to be fastened together to produce a tubular shroud adapted to surround a gas turbine engine and form the inner wall of a bypass duct. The disclosed shroud eliminates the prior complex corner fittings connecting the semicircular center portion of the shroud to the extending flanges and provides simple, integral corners.

Abstract: An integral "C" duct for the thrust reverser region of ducted fan gas turbine engines. The integral duct 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 engine nacelle. The "C" duct basically consists of right and left "C" shaped ducts with bifurcations (radial flanges) permitting the halves to be fastened together to produce a tubular duct adapted to surround a gas turbine engine and form the inner wall of a bypass duct. The disclosed duct eliminates the prior complex corner fittings connecting the "C" shaped portion of the duct and the bifurcations and provides simple, integral corners.

Abstract: A method and apparatus for making a preformed maskant sheet having a plurality of perforations corresponding to a pattern of perforations desired in a structure. A shaping surface is prepared on a sheet having the contours of the structure to be perforated. The surface is perforated in the precise desired pattern. A plenum is secured and sealed to the back of the shaping sheet, enclosing all of the perforations. A line for introducing air into the plenum is connected to the plenum. A coating of maskant material is sprayed onto the surface (which has mold release properties) while positive air pressure is maintained in the plenum. Air flows out through the perforations, keeping them clear of maskant. The maskant is then cured and the resulting self-supporting sheet is removed from the surface and placed against the structure to be perforated. The holes may then be formed by any suitable method, such as grit blasting etching or the like.

Abstract: A system for selectively venting cool bypass duct air into selected locations between a gas turbine engine and the engine shroud. The venting system 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 engine casing. The venting system basically comprises tubes inserted in holes in the engine shroud which separates the bypass duct from the engine compartment. Often sensors, electronic components or the like are advantageously located in the engine compartment. However, elevated temperatures in the engine compartment often damages or degrades those components. The vent tubes are positioned so as to direct cool air onto those components. A large number of vents may be provided in the shroud as manufactured, each plugged at manufacture, with only those opened which are needed for a specific engine with specifically located heat sensitive components.

Abstract: A method and apparatus for making an insert for selectively, locally, densifying panels having a honeycomb core and at least one face sheet. At least two narrow, long foil strips are fed from supply rollers through a corrugating device which corrugates at least one of the strips. Preferably, the depth of corrugations vary greatly between adjacent strips. From the corrugating device the strips go to a take up reel which winds the strips into a flat pancake coil. When the desired coil diameter is reached the coil is secured to prevent unwinding and the coil is removed from the reel. The coils are used to replace portions of the honeycomb core to locally improve density, strength and thermal transfer characteristics of the panel.

Abstract: An improved synthesis for PMR-type polyimides, including first preparing a dimer of 5-norbornene-2,3-dicarboxylic acid, or acid ester or anhydride and 4,4'methylene dianiline. This dimer is then reacted with one of the following:1. the reaction product of a primary aromatic diamine and an aromatic dianhydride.2. an aromatic dianhydride.3. a mixture of a primary aromatic diamine and an aromatic dianhydride, or an ester of an aromatic tetraacid or an aromatic tetraacid.The resulting polyimide prepolymer exhibits superior physical properties and is substantially free of undesired impurities and unreacted 4,4'-methylene dianiline.

Abstract: An improved synthesis for PMR-type polyimides, including first preparing a dimer of 5-norbornene-2,3-dicarboxylic acid, or acid ester or anhydride and 4,4'methylenedianiline. This dimer is then reacted with the reaction product of the dimethyl ester (or dianhydride) of 3,3', 4,4'-benzophenonetetracarboxylic acid and 4,4'-methylenedianiline. The resulting polyimide prepolymer exhibits superior physical properties and is substantially free of the undesired trimer of 5-norbornene-2,3-dicarboxylic acid, or acid ester or anhydride and 4,4'-methylenedianiline. When this dimer is reacted with 3,3', 4,4'-benzophenonetetracarboxylic acid dianhydride methylenedianiline amic acid mixture, the resulting polyimide prepolymer exhibits superior physical properties.

Abstract: A double layer structural honeycomb sandwich noise suppression panel for use in severe environments such as aircraft turbine engine housings. Two honeycomb core sheets having multiple cells transverse to the sheets are sandwiched around and bonded to a septum sheet consisting of a wire cloth sheet alone or bonded to a sheet of perforated material. A thin sheet of impervious material is bonded to one surface of the sandwich and a facing of thin perforated sheet material is bonded to the other sandwich surface. The panel has improved simplicity, structural strength with unusually light weight.