Abstract: A method of folding the main rotor blades of a helicopter for storage in which blade supports are removably attached to the nose and tail of the fuselage of the helicopter. A first and second main rotor blades then are aligned with the longitudinal axis running from the forward blade support to the aft blade support. The first and second blades are placed upon, and restrained from rotation in, the blade supports. Then the first and second blades are permitted to fold about the rotor assembly of the helicopter by releasing a locking member of each blade. The first and second blades are folded by rotating the main rotor assembly while restraining from rotation the first and second blades in the forward and aft blades supports, respectively. After the rotor assembly is rotated through approximately 90 degrees, a third and fourth of the rotor blades are aligned with the longitudinal axis running through the forward and aft blade supports and the first and second blades are fully folded.

Abstract: Apparatus indicates changes in blade pitch of variable pitch blades by detecting relative displacements of first and second members of a blade pitch actuator. The members are selectively displaced to change the pitch of the blades. The apparatus includes sensors which provide output signals to a microprocessor, which determines displacement of each member with respect to a frame of reference. The microprocessor takes the difference between the displacements of the two members to determine the relative displacement, which is indicative of a change in blade pitch.

Abstract: A hydraulic circuit arranged to prevent the load pressure in one of the hydraulic actuators at the time of starting from becoming abnormally high thereby preventing fluid under pressure from being relieved by the safety valve when a plurality of hydraulic actuators are operated at the same time, wherein the function of one of the pressure compensating valves is temporarily enhanced by introducing the load pressure in the hydraulic actuator so as to supply a large quantity of fluid under pressure to the hydraulic actuator connected to the pressure compensating valve so that the operating speed of the hydraulic actuator can be increased.

Abstract: A gas turbine bucket and a gas turbine nozzle applied with a ceramic coating comprises a base material of the bucket and the nozzle made of a heat resisting alloy; a plurality of coating layers for the front portion consisting of, a mixture layer which comprises a ceramic material and metal and which is formed on the base material, an alloy layer which comprises an alloy material exhibiting excellent resistance to high temperature oxidation and corrosion and which is formed on the mixture layer, and a ceramic layer which comprises ceramic material and formed on the alloy layer. Such ceramic coating has a satisfactory thermal barrier effect on the base material of the gas turbine bucket and nozzle.

Abstract: Apparatus for controlling the steam pressure at the exit of the last row of blades of a steam turbine by means of an adjustable guide vane assembly having a plurality of vane segments supported by the bearing cone that are moved to change the cross-sectional area of the exhaust flow passage so as to improve turbine efficiency under varying operating conditions by minimizing the average pressure in the annulus following the last row of turbine blades.

Abstract: This invention relates to an assembly of a hydraulic motor and a combined device for immobilization, comprising: a reaction cam; a cylinder-block mounted to rotate with respect to the reaction cam; a first immobilization member fast with the cylinder-block; a second immobilization member fast with the reaction cam and capable of being disposed in a first position, in which the first and second immobilization means are fast with one another, and a second position, in which these first and second immobilization members do not cooperate for their mutual immobilization. The device for adjusting the relative position of the first and second immobilization members comprising a jack comprising a chamber.

Abstract: An aircraft propeller blade utilized in subsonic flight at relatively slow turning applications with relatively high power coefficients. The blade in plan form is tapered at both ends with the maximum chord approximate the 44% percent station of the blade, the leading edge of the blade being swept behind the longitudinal axis of the blade near its tip and the trailing edge is convex and essentially straight from its maximum chord outward to the tip.

Abstract: A spring and lever arrangement for imparting a spring force to a plunger of a control valve in a brake booster by operating a solenoid member during a brake application. Movement of the plunger by an operator input force allows a pressure differential to develop across a moveable wall and produce an original output force which is supplied to a pressurizing member. Resistance to movement of the pressurizing member creates a reaction force. The reaction force balances the spring force and operator input force to terminate the development of the pressure differential while correspondingly modifying the output force supplied to the pressurizing member. A switch allows an operator terminate the operation of the solenoid to effectively obviate the spring force and allow the original output force to be produced by the operator input force.

Abstract: Hydraulic control systems are useful for controlling actuation of hydraulic motors. Some such systems use spool type valves while other systems use poppet type valves, both of which have their advantages and disadvantages. The present hydraulic control system is a hybrid system utilizing a combination of both a spool type control valve and poppet type control valves in a single work circuit. Specifically, a spool type control valve has an inlet port connected to a variable displacement pump and a pair of flow amplifying poppet type valves are serially disposed between a pair of motor ports of the spool type valve and a pair of actuating chambers of a double acting hydraulic motor. The spool type control valve is operative to control pump-to-motor flow while one of the poppet type valves is operative to control motor-to-tank flow.

Abstract: The invention is a helicopter blade crack detection system for blades that are hollow and pressurized or evacuated to a low pressure A rotating assembly having a rotating indicator assembly photo-optically communicates to an airframe detection assembly providing high reliability, ease of maintenance, and EMI secured.

Abstract: An infinitely variable differential hydrostatic transmission utilizing a fixed displacement pump/motor and a variable displacement pump/motor interconnected with appropriate valving, to provide a mechanical/hydraulic differential drive which is capable of achieving an overall efficiency in the 98.degree.-99.degree. range. In the preferred embodiment, which utilizes axial piston type pump motors, pistons in multiples of four are utilized in order that each piston will have a piston located 90.degree. from it to serve as its control valve. The fixed and variable displacement motor/pump are provided as an integral unit containing bearing mountings, cylinder barrels, valve ports, piston seal mountings, hydraulic flow passages, pressure reservoirs and manifolding by forming a series of individual segments and sealing them together into a single structural unit. A unique mounting arrangement is utilized to positively attach the pistons to an anti-friction swashplate which eliminates all side loads on the piston.

Abstract: An engine-driven pump supplies pressurized hydraulic fluid to vehicle brake and steering circuits. A ground driven variable displacement pump controlled by a control circuit is de-stroked when the engine-driven pump is operational. The variable displacement pump includes a movable piston which divides a bore into a pilot chamber and a pump chamber. An outlet line with a check valve communicates fluid one way from the pump chamber to the vehicle circuits. An inlet line with a check valve communicates fluid one way from a reservoir to the pump chamber. A ground-driven rotatable cam member reciprocates the piston. A spring urges the piston towards the cam member and towards a full stroke position. A pilot line which communicates fluid pressure from an outlet of the engine-driven pump to the pilot chamber. When the engine-driven pump is operational the pressure in the pilot line moves the piston away from the cam member, thus de-stroking the variable displacement pump.

Abstract: A hydra-jack screw apparatus is provided for exerting a force against an object, for adjusting the magnitude of the force exerted against the object, and for providing a visual indication of the magnitude of the force exerted against the object. The apparatus is comprised of a base member housing a piston chamber, a jack screw extending from the bottom of the base member, a fluid pressure gauge mounted on the base member, and a pair of pistons received in the piston chamber for reciprocating movement. One of the pistons has a piston rod that extends through a center bore of the jack screw and engages against an object against which a force is to be applied. The second piston has a piston rod that extends from the piston chamber of the base member and is attached to a manual forced adjusting knob. A volume of fluid is contained in the piston chamber between the first and second pistons, and as the manual knob is turned, the pressure of the volume of fluid is adjustably increased or decreased.

Abstract: A hydraulic actuating system and method comprises a pump which continuously circulates hydraulic fluid out of a reservoir into a pressure line limited to a predetermined maximum pressure by a pressure-limiting valve and a control valve connected to the pressure line controlling flow of hydraulic fluid to an operating cylinder. A clearance volume in communication with the pressure line collects compressed air entrained in the hydraulic fluid flow which upon opening of the inlet valve expands to displace a portion of the volume of flow of hydraulic fluid required for actuation of the operating cylinder.

Abstract: A pitch change system (30) for varying the pitch of the blades (16) of a multi-bladed propulsor (10) comprises a pitch change actuation assembly (40) and a pitch change drive assembly (70) for selectively actuating the pitch change actuation assembly (70) whenever it is desired to change blade pitch. The pitch change actuation assembly (40) comprises a ballscrew (42), a ballscrew nut (44) threadably mounted to the ballscrew (42), and a pitch stop assembly (100) having a retractable feather stop (135) which in its normal position prevents the ballscrew (42) from driving the ballscrew nut (44) to move the blades (16) beyond the coarse pitch setting corresponding to blade feather, but in its retracted position permits the ballscrew (42) to drive the ballscrew nut (44) to move the blades (16) through feather to a desired reverse pitch setting.

Abstract: Noise is reduced on an aircraft engine of the type having aft mounted propeller blades 10 which pass through exhaust gas streams 20 expelled from circumferentially spaced nozzles 14. The nozzles 14 are rotated, or the exhaust flow deflected, such that the high velocity exhaust streams 20a expelled from the nozzles 14 are directed away from their normal axial direction to impact the blades 10 at the same relative angle of attack 36a as the relative angle of attack 34 of the low velocity ambient air stream 22 thereby reducing fluctuations in blade lift and the associated noise.

Abstract: A modular digital actuator is formed by interconnecting a plurality of modules. Each of the modules includes a housing having a pair of different sized axially extending cylinder sections in which is received a T-shaped piston with the top of the T mating with the larger cylinder and the leg of the T forming a piston in the smaller cylinder. The leg of the T is hollow and forms a cylinder to receive an axially extending piston forming shaft to thereby provide three preferably different sized cooperating piston and cylinder areas, one formed in the cavity or hollows of the leg of the T, a second formed between the top of the T surrounding the leg of the T and the junction between the larger cylinder section and smaller cylinder section and the third formed in the smaller cylinder section between a closed free end of the smaller cylinder section and the leg of the T surrounding the piston forming shaft. The top of the T forms a piston wall in a fourth hydraulic cavity.

Abstract: A pedestal formed bulged on a rear wall of a booster shell and attached to a vehicle body by four connecting bolts has a pheripheral wall whose length from a general wall of the rear wall of the booster shell to a seating face wall of the pedestal becomes larger toward each of corners of the pedestal. This ensures that the concentration of a stress produced at each of the corners of the peripheral wall of the pedestal can be moderated, thereby providing an improvedment in durability of the rear wall of the booster shell and suppressing an increase in internal volume of the pedestal to the utmost.

Abstract: A wind force-operated cycling ornament, comprising a body shaped like a cyclist and mounted on a base, which can be mounted on a flat surface by screws or a double-sided adhesive tape, two wheels mounted on said body at two opposite sides and connected by a wheel axle, a fan mounted on said body and forced by the power of wind to rotate said wheels through a transmission gear set, and a pair of driven plates and a pair of driving plates movably mounted between a pair of pegs on said body and two contact points on said wheel, and wherein said driven plates are respectively shaped like the upper part of the leg, and said driving plates are respectively shaped like the lower part of the leg; rotating said fan causes said driven and driving plates to alternatively rotate back and forth.

Abstract: In the case of a hydraulic control device for an oscillating load moving system comprising a double-acting hydroconsumer (V), which is adapted to be selectively connected to a pressure source (P) or to a reservoir (T) via two separate main lines (9, 10) and a control valve (C), and further comprising a load supporting valve (H), which is arranged in at least one main line (10) between the control valve (C) and the hydroconsumer (V) and which is adapted to be opened from the other main line (9) via a pilot line (16), a damping device (X), which consists of a bypass line (23) and an interference throttle aperture (D2), is connected to the pilot line (16) of the load supporting valve (H). The pilot line (16) has provided therein a throttle aperture (D1) which is smaller than the interference throttle aperture (D2).