Abstract: Viscoelastic damping material (45, 80 and 105) effectively damps the resonant responses of a mirror (10) and a mount (12) therefor to vibratory disturbances thereof by such phenomena as pressure pulses in a pulsed chemical laser cavity.

Abstract: A blade pitch angle control system for a wind turbine includes an improved control means (95) for providing a minimum pitch angle reference signal indicative of desired blade pitch at wind velocities less than rated. The control means includes means (35 and 30) for providing signals indicative of generated (output) power or torque and the rotational frequency of the wind turbine rotor. The output and rotor speed signals are input to a function generator which, in response to such signals, provides a signal indicative of the minimum pitch angle.

Abstract: An improved method is disclosed for forming articles, especially airfoils, comprised of a fiber reinforced plastic bonded to a metal object. In the manufacture of a propeller blade a subassembly is made by coating a metal spar with a certain class of adhesive to a depth of 5-40 mils to compensate for dimensional variations in the spar surface, transferably coating the interior of a subassembly mold with the adhesive, then inserting the coated spar into the mold and injecting a lightweight filler material. The adhesive and filler are then precured and the subassembly removed from the mold. A fibrous reinforcing material, such as glass fiber cloth, is then used to cover or wrap the subassembly, the subassembly thus covered is placed in a second mold and a synthetic polymeric material such as epoxy resin, previously or subsequently applied, is then cured.

Abstract: Snap-action operation of a servo diverter valve (70) and an associated pressure responsive switch (115) is achieved by controlling the pressurization and depressurization of the valve with a nozzle (140) operated by a pressure responsive bellows actuator (160) disposed in a chamber 145 having a flow restrictor 220 in an outlet thereof.

Abstract: Sensed pressures are applied to a differential pressure sensor such that one-half the sensed pressure drop is applied to each of a pair of redundant pistons. Failure of one of a pair of bellows which seal opposite faces of the pistons from one another effects application of the entire pressure drop across the piston associated with the remaining, operable bellows for fail-safe operation of the sensor.

Abstract: An actuator (10) tolerant of ballistic damage thereto includes a piston (25) longitudinally reciprocable within a cylinder (15) and connected to a rod (30), the piston comprising a plurality of longitudinally stiff, circumferentially spaced ribs (35) joined by a bulkhead (40) which transfers hydraulic loading to the ribs and readily ruptures in response to impact with an obstruction (45) in the cylinder wall due to for example, ballistic damage to the actuator. The bulkhead carries a sealing ring (60) for sealing leakage around the piston and may be formed integrally with the ribs or separately therefrom and attached thereto as an end cap to the piston. Analogous structure may be employed in a gland (20) for the actuator to accommodate ballistic damage to the rod.

Abstract: A rotary metering valve (10) includes a pair of windows (145, 200) in mutual registry with one another, the windows defining a flow passage through the valve. The geometries of windows are such that closing the valve sweeps contaminants trapped therein, inwardly, thereby enhancing the effectiveness of the output torque of the valve's actuator (75) in breaking apart the contaminants for subsequent removal by flow through the valve.

Abstract: A focused optical input signal is applied to an optically absorbent wall portion of a supply nozzle 40 in a fluidic device to cause boundary layer separation of flow therein. The boundary layer separation turns the flow to achieve a desired output from the device.

Abstract: Required preloading of a valve closing spring (80) in a pressure operated, fluid handling device (10) is determined by mechanically precompressing the spring, applying operating pressure to the device and relieving the bias on the spring until the operating pressure opens the valve, the thickness of a shim (75) for effecting such preloading being equal to the difference between the change in spring length due to the precompression thereof and the change in spring length due to relief of the precompression prior to spring opening.

Abstract: An unfocused optical input signal is applied to an optically absorbent wall portion of an interaction region 30 in a fluidic device to effect flow impedance modulation thereat. The flow impedance modulation adjusts the velocity profile of the flow to achieve a desired output from the device.

Abstract: A reduced fuel flow to a gas turbine engine experiencing impending overspeed operating conditions is provided through a line (250) which bypasses the main shutoff valve (70) of the engine's fuel control (20). A transfer valve (260) disposed in the bypass line actuates the shutoff valve in response to such overspeed conditions while opening the normally closed bypass line. A flow resticter (275) and the fuel control's main pressure regulating valve (210) combine to maintain the reduced fuel flow at a predetermined valve.

Abstract: Pneumatic indexing of a shaped component (127) is attained by adjusting the position of the component until fluid passages (130) therein are aligned with supply and vent passages (100) and (110) in a pneumatic head (15). Such alignment causes the relief of supply passage pressure through the vent passages and a resulting retention of the shaped component in an indexed position thereof.

Abstract: A manipulator (10) including a compliant suction means (215 and 220) and two pairs of independently operable jaws (55, 60) precisely and delicately locates a workpiece (300) for delivery thereof to a location remote from that at which the piece is picked up.

Abstract: Initiation of piston movement in a fluid actuator and sustained piston movement at a controlled rate are achieved by control of servo pressure in the actuator.

Abstract: A piezoelectric fluidic power supply comprises two piezoelectric devices (30, 31) connected both electrically and fluidically. Each device has a movable piston end (26, 27) which extends into a corresponding fluid chamber (23, 24), each piston variably restricting fluid flow through its corresponding fluid chamber. The first piezoelectric device, responding to fluid pressure changes, acts as a power generating device (30). The second piezoelectric device, responding to the electric power flow of the power generating device acts as a cycle control device (31) by modulating the fluid pressure on the first device. This arrangement effects a cycling of the two pistons, consequently generating electric power. Such an arrangement provides integral fluidic feedback control with inherent impedance matching between the fluid and the piezoelectric components.

Abstract: In a propeller pitch control system, a selector 10 isolates engine (42) speed control in one of two engine governor (175 and 300) systems. The selector is input with fluid pressure signals from a pair of pilot valves (215 and 325), each operated by a corresponding one of the governors. The selector passes the signal of lowest magnitude to an actuator 40 which sets blade pitch in accordance with the magnitude of the signal whereby the governor providing such signal (through its associated pilot valve) controls engine speed independently of the other governor.

Abstract: Atmospheric conditions experienced by a vehicle are controlled in response to the sensing of an absolute value of a parameter indicative of desired conditions and thereafter, when conditions within an acceptable range are achieved, in response to a differential sensing of variations of the parameter from that achieved on the basis of the absolute sensing.

Abstract: A thruster (10) including a heater (65) remote from the location of propellant decomposition, includes a means such as a thermal diode heat pipe for conducting heat unidirectionally, from the heater to the decomposition location, extending the useful life of the thruster.

Abstract: An apparatus for scavenging vomitus from the interior of the helmet of a life support suit comprises a normally furled mask (10) defined by a sidewall structure (20) connecting to a suction conduit (90). The mask is expanded into registry with the mouth of the user by inflation of bellows (40) located within the sidewall structure. Suction applied to the interior of the mask positively traps vomitus on a liquid absorbent filter (85).

Abstract: An actuator (10) tolerant of ballistic damage thereto includes a piston (25) longitudinally reciprocable within a cylinder (15) and connected to a rod (30), the piston comprising a plurality of longitudinally stiff, circumferentially spaced ribs (35) joined by a bulkhead (40) which transfers hydraulic loading to the ribs and readily ruptures in response to impact with an obstruction (45) in the cylinder wall due to for example, ballistic damage to the actuator. The bulkhead carries a sealing ring (60) for sealing leakage around the piston and may be formed integrally with the ribs or separately therefrom and attached thereto as an end cap to the piston. Analogous structure may be employed in a gland (20) for the actuator to accommodate ballistic damage to the rod.