Abstract: A process is disclosed for cleaning and passivating stainless steel apparatus used in the manufacture, transport, storage and/or use of nitrogen oxides. The process involves sequentially treating stainless steel surfaces of apparatus which contact a nitrogen oxide, with various solutions, in such manner as to enable the apparatus to substantially maintain the quality of the nitrogen oxide to be manufactured, transported, stored and/or used therein. Thus, for example, the purity of nitrogen tetroxide, used as a propellant for rocket engines and the like, may be maintained longer, the shelf life significantly increased and rocket engine flow decay problems markedly reduced through use of the disclosed cleaning and passivating process.

Abstract: A helicopter power train is disclosed in which the rotor tip-path plane (218) inclination relative to the helicopter air frame (200) is achieved by blade flapping motions distributed through a plurality of drive train components rather than through blade flapping motion about a single flap hinge. Rotor tip-path plane flapping is accommodated by resilient transmission mounts (24, 25, 26 and 27) to the extent of approximately 25%, by a flexible mast (208) extending upward from a transmission (11) to the extent of approximately 20%, by a hub (213) having flexure members to the extent of approximately 50% and by flexible blade structure (214, 216) having beam bending to accommodate approximately 5% of the rotor flapping motion. The hub (213) comprises a plurality of yokes (260, 262) each of which is an elongated plate having flexure members to accommodate blade flapping. The yokes (260, 262) are stacked on the mast (208) to form the hub (213).

Abstract: A compact bistable, magnetically operated fuel valve embodies an upper portion comprising a pair of similarly poled and spaced apart permanent magnets defining vertical side walls of an enclosure space which is completed by a pair of pole plates sandwiching the permanent magnets therebetween. The pole plates provide pole faces at their opposite ends and the two sets of pole faces define air gaps. Within the space there is located an armature of plate like form centrally mounted on an upstanding flexure tube. A valve actuating rod is connected at one end to the free end of the flexure tube and projects therethrough downwardly into a valve block. The valve block presents at least one fuel chamber provided with means for supplying pressurized propellant thereto and is provided with oppositely directed fuel outlets to which oppositely directed thrusters are connected.

Abstract: This invention relates to helicopter rotors and more particularly to rotor mounting involving a composite fiber-reinforced unitary yoke with resilient inplane restraints.

Abstract: A drive shaft coupling (10) where lubricant is to be maintained in a zone of contact between a crown gear (17) and a nested interior annular spline structure (18) which is substantially coaxial to said crown gear (17). Support structure supports the crown gear (17) and is coupled centrally to the shaft (10). A resilient seal ring (35) on the shaft (10) is located at about the medial plane of the crown gear (17). A flanged cylindrical wear sleeve (30) encloses the spline (18) and crown gear (17) and a movable annular resilient contact with the seal ring (35).

Abstract: An electrically operated fastener driving device comprising a housing structure providing a manually engageable handle for engaging a user to portably operate the device, a front wall disposed in vertically extending relation forwardly and below the handle and a vertically extending fastener drive track disposed closely adjacent the front wall. A solenoid is carried by the housing structure forwardly of the handle and rearwardly and above the drive track and includes an elongated plunger having a longitudinal axis inclined with respect to the vertical. A cam and cam track mechanism is disposed between the upper end portion of the fastener driving element slidable in the drive track and the lower end portion of the plunger for causing a downward stroke of the plunger in response to the energization of the solenoid to effect a drive stroke of the fastener driving element.

Abstract: A collapsible fastener comprises a tubular plastic having a head on one end for bearing against one surface of the work. There is an internally threaded tail portion at the shank end of the sleeve. The shank is slotted to define strips which are notched internally and intermediate the ends. The slots increase in width from their ends to the area of the notches. A screw extends through the sleeve and is devoid of threads intermediate its ends to prevent overtorquing. A radially tapered annulus is positioned atop the sleeve for sealable engagement with the screw head in the assembled condition.

Abstract: A pumping system which converts a source of gas under pressure to hydraulic fluid under pressure. The system includes three free floating pistons coupled through control valves to the pressurized gas source on one side and through appropriate check valves to hydraulic fluid on the other side. The pistons are reciprocated within respective cylinders by application of the pressurized gas to one side thereof and by application of the return pressure of the hydraulic fluid to the other side thereof. Appropriate porting on the gas side of the pistons sequentially applies the gas under pressure to the three pistons to synchronize reciprocation of them so as to provide a continuous flow of fluid under pressure, upon demand, to a load.

Abstract: A case is disclosed for containing an electronic watch module of the type having a display face and internal function switches manually operable by means of externally protruding depressible control buttons. The case includes a base component defining an open cavity for receiving the watch module, and a cover component with a window. Fasteners are employed to assemble the cover component to the base component at a position overlying the watch module, with the module display face visible through the cover window. Access openings in the assembled combination of the base and cover components are aligned with the module control buttons, and a spring is interposed between the module and the base component to resiliently urge the module into a fixed position within the case. The control buttons are concealed behind depressible spring contact sections which protrude outwardly through the access openings to provide a neat decorative appearance.

Abstract: A method of thread rolling a cylindrical sintered P/M blank is provided comprising, forming a sintered cylindrical powder metal (P/M) blank of density ranging from about 75% to 92% of the actual density of said metal blank having a selected diameter larger than the final pitch diameter of a predetermined roll threaded product produced therefrom and not substantially exceeding the outside diameter of said predetermined roll threaded product. The P/M blank diameter selected is substantially inversely related to the density of the blank, the P/M diameter selected being correlated to produce a substantially full thread. The sintered P/M blank is then thread rolled using a threading die corresponding to the gage of the predetermined roll threaded product to be produced.

Abstract: The top sharpening saw chain includes a cutter link having a body portion, an integral cutting element and a depth gauge. The cutting element comprises a top plate having a bottom surface, a top surface face spaced therefrom and terminating rearward thereof and a leading connecting surface extending between the top surface and the bottom surface. The juncture of the connecting surface and the bottom surface defines the only cutting edge of the cutting element.

Abstract: There is disclosed an improved upper-stage rocket motor/engine assembly of the type which comprises in combination with the basic rocket engine/motor and rigid or fixed nozzle thereof one or more telescoping nestible-extendible truncated cone-shaped collars of rigid structural form, and a further deployable perimetrically attached skirt formed of sheet metal or the like which is pleat-folded inwardly from an initial truncated cone-shaped configuration into a generally planar configuration. The assembly when inoperative is stowed within the basic engine/motor and nozzle profile; but in association with engine/motor firing the extendible components thereof are progressively deployed in accord with an improved technique to provide the desired extended length and plume exiting diameter/area nozzle effect.

Abstract: There are disclosed aqueous dispersions of salts, e.g., tertiary amine salts, of polyamine-extended, aromatic polyisocyanate-based prepolymers having carboxylic groups, especially such dispersions made from prepolymers of polyisocyanates in which the isocyanate groups are on different aromatic rings. These products, as well as, aqueous dispersions of salts of prepolymers of aromatic polyisocyanates can be made from blocked, aromatic polyisocyanate-based prepolymers, particularly oxime-blocked prepolymers. The polymer salts can have sufficient neutralized, carboxylic groups to provide stable, aqueous dispersions, and the dispersions of the polyamine-extended polymers have infinite dilutability with water and excellent resistance to gelling upon freezing and thawing. Carboxylic groups can be supplied to the prepolymers by reactants having two or more groups containing isocyanate-reactive hydrogen atoms employed in making the aromatic isocyanate prepolymers, particularly dihydroxy alkanoic acids.

Abstract: A voltage regulating circuit for eliminating flicker in lights fed by an electric generator driven by an internal combustion engine comprises a transformer having an input connected in series with the output of the generator and with the lights, and a control winding connected in a control circuit. The control circuit comprises a resistor and a transistor or solid state switch for shorting the resistor except during the power strokes of the engine when the engine speed and hence the voltage of the generator are cyclically higher. The voltage at the output of the transformer is thereby reduced during the power strokes of the engine to a value substantially equal to the voltage during exhaust strokes, thereby eliminating visible flicker in the lights.

Abstract: A storage stable, weather resistant, one-component air cured urethane composition. The composition comprises a moisture activated curing agent and a polyisocyanate prepolymer. The moisture activated curing agent comprising an oxazolidine ring. The polyisocyanate prepolymer comprises at least two unreacted isocyanate groups and is the reaction product of a polyester polyol, a low molecular weight polyol having at least three hydroxy groups and isophorone diisocyanate. The polyester polyol and low molecular weight polyol are reacted with the isocyanate at an equivalent weight ratio of polyester polyol to low molecular weight polyol of from 0.25:1 to 5:1.The invention also comprises the method for coating a surface with the composition and the resulting coated article.

Abstract: Individual blade control of a helicopter rotor is accomplished by rotation of a mast (10) about a standpipe (12) where an individual blade (16) is coupled to the mast through a hub (18). Pilot input signals are transmitted by fly-by-optic transmission lines (14) through a fiber optic slip ring (40,42) to signal generators (134, 136, 138) for each of three sections of triplex actuators (76-79) coupled to individual rotor blades. Hydraulic fluid for positioning each of the actuators (76-79) is provided by electrohydraulic power packages (88, 90 and 92) where each package includes a pump and alternator. As each blade rotates about the mast (76) the pitch angle changes by individualizing the output of the signal generators (134-138) for each actuator.

Abstract: A three-part seal to be fixed in a gland formed on the first of two mating cylindrical structures in a hydraulic apparatus. A continuous Teflon nondeformable bearing ring is provided in the gland. The bearing ring has a first cylindrical surface for contact with the second cylindrical structure, a second cylindrical surface opposite the first surface and a conical rearward facing end surface. A continuous Teflon nondeformable backup seal ring is provided in the gland for mating with the rearward facing conical end surface of the bearing ring against its forward facing conical end surface. A continuous compressible resilient ring is provided on the side of the bearing ring opposite the second cylindrical structure for contacting the bearing ring and the backup seal ring.