Abstract: An adjustment arrangement for a hydraulic brake actuator (11) of the type having a piston (17) which moves a preferred distance within a cylindrical bushing (15) portion of a housing between a quiescent retracted position with a preferred clearance space between one piston end and a brake mechanism, and an extended position with the piston end engaging and actuating the brake mechanism in response to the application of hydraulic fluid pressure includes a return spring (23) which, upon relief of the hydraulic pressure, urges the piston (17) back from the brake mechanism engaging position to the retracted position. There is an internally disposed mechanical piston clearance space adjustment feature including an expandable sleeve (33) which surrounds a cantilevered pin (37) having a split expander ring (35a, 35b) near a free end thereof. Upon excessive piston (17) travel, the sleeve moves along the expander ring (35a, 35b) to establish a new retracted piston position.

Abstract: The present invention generally relates to mechanisms for preventing undesirable oxidation (i.e., oxidation protection mechanisms) in composite bodies. The oxidation protection mechanisms include getterer materials which are added to the composite body which gather or scavenge undesirable oxidants which may enter the composite body. The getterer materials may be placed into at least a portion of the composite body such that any undesirable oxidant approaching, for example, a fiber reinforcement, would be scavenged by (e.g., reacted with) the getterer. The getterer materials) may form at least one compound which acts as a passivation layer, and/or is able to move by bulk transport (e.g., by viscous flow as a glassy material) to a crack, and sealing the crack, thereby further enhancing the oxidation protection of the composite body.

Abstract: A convertible aircraft brake assembly (10, 60, 77, 78, 83, 85, 96, 120, 130) designed as original equipment to have heat sinks comprising a steel heat sink (20, 70, 80, 90, 91, 100, 110, 122) aircraft brake assembly and a carbon—carbon composite heat sink (40) aircraft brake assembly. When the aircraft brake assembly is converted from one type of heat sink to the other, the conversion is accomplished with minimal changes in component parts. The conversion can be accomplished without any changes in the piston housing (14), torque tube (12), and wheel (30) because the heat sinks include therein respective components which enable each heat sink to be utilized with the commonly used piston housing (14), torque tube (12), and wheel (30).

Abstract: An improved fluid flow measuring device having more nearly linear response characteristics over a wide range of fluid flow rates measures the force exerted on a fluid flow sensing element (21, 37, 41, 47, 55, 61) located in the fluid flow. The effective area of the sensing element subjected to the fluid force decreases as the flow rate increases and increases as the flow rate decreases thereby compensating for the nonlinear relationship between fluid flow rate and the force exerted thereby. The sensing element may retract somewhat into a calm or minimal flow region (27, 35) in response to increased flow rate. The sensing element may include resilient vanes (45, 51, 52, 53, 57, 59) which bend thereby reducing their effective area in response to increased flow. The sensing element may include one or more flow passing apertures (43, 49) the size of which varies with flow rate.

Abstract: A fuel control system for supplying metered quantities of fuel from a fuel supply (11), through a boost pump (13), a filter (21), a high pressure fuel pump (14), a metering valve (15) and a pressurizing valve (17) to an engine fuel manifold (19) includes an ecology valve (43) which provides a fuel flow path (41, 42, 71, 46, 18) between the pressurizing valve (17) and the engine fuel manifold. The status of the ecology valve (43) is solely determined by the status of the pressurizing valve (17). The ecology valve (43) includes a housing (93, 95, 97) with a piston (61) disposed therein which is reciprocable between two extreme positions. The piston (61) defines, in conjunction with the housing, a variable volume chamber (55) for withdrawing a one piston stroke volume of fuel from the engine fuel manifold when the engine is de-energized and the piston (61) moves from one extreme position to the other thereby purging the fuel manifold of fuel.

Abstract: An arrangement for assuring synchronous motion of a pair of actuators (65, 67) includes two gear racks (99, 101) moved by cables (95, 97) fixed to remote hydraulic actuators (65, 67) to sense the motion of the actuators (65, 67). The racks (99, 101) drive pinions (111, 113) and attached bevel gears (113, 115) at identical rates and an idler bevel gear (119) that spins in-place on its own axis when actuator travel is synchronous. When the actuator (65, 67) travels are synchronous, no error signal is sent to a synchronizer servo valve (105), however, when one actuator's speed is too great, an output error signal from the idler gear (119) is sent. The output signal positions a servo valve (105) to release pressure which is holding open one of two throttling valves (107, 109). Releasing the pressure allows the throttling valve (107, 109) to be closed by a spring (129, 131) and restrict flow to the actuator (65, 67) which is traveling the fastest.

Abstract: A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

Abstract: The present invention provides an inexpensive, open cell, mechanically robust and graphitizable foam preform. The graphitizable foam is produced via a modified standard flower foam formulation. The invention provides a modified formula for such flower foams wherein a mesophase material is incorporated along with a corresponding reduction in the resole component. The mesophase material replaces 30-70% by weight (a target of 50% by weight) of the resole component of the formulation. The formulation is heated to effect foaming of the mixture, and then carbonized to produce an open cell, graphitizable foam preform.

Abstract: An unbalance compensated bypass valve (23) for a gas turbine engine fuel supply system is responsive to the fuel pressure differential across a fuel metering valve (15) to open and close a bypass orifice (37, 39, 41). The bypass valve (23) selectively supplies high fuel pressure to providing a counterbalancing force against an annular area (47) of the bypass valve piston 34 to compensate for increased restorative forces of a helical reference spring (57) as that spring is compressed as well as to compensate for other unbalance conditions within the valve (23). The piston (34) includes additional sidewall openings (69, 70, 71) which function during a "shut-off" condition to divert all fuel flow from an inlet of the metering valve (15) back to a fuel pump (13) inlet. The piston (34) also includes further sidewall openings (73, 75) which provide a controlled fuel leakage from a bypass valve inlet line (25) to the bypass valve pressure sensing inlet (29).

Abstract: Disclosed are mechanochemical processes for the synthesis of high performance electroceramics from organometallic precursors, and compositions resulting from the processes.

Abstract: A thermomechanical pressing ("TMP") method for obtaining rapidly a high density (1.2 g/cm.sup.3 or higher) carbon/carbon composite preform from any carbon fiber including PAN-based carbon fibers and industrial coal-tar or petroleum pitches (including synthetic derivatives) having a melting point m.p.=80-350.degree. C. Green preforms may be prepared from mixtures of carbon fibers and pitch, and the resulting mixture is formed to impart a cylindrical shape to the green preform. The green preform is charged into a metallic mold where it is heated, stabilized, pressurized for a period of time, and cooled.

Abstract: The present invention provides an inexpensive, open cell, mechanically robust and graphitizable foam preform. The graphitizable foam is produced via a modified standard flower foam formulation. The invention provides a modified formula for such flower foams wherein a mesophase material is incorporated along with a corresponding reduction in the resole component. The mesophase material replaces 30-70% by weight (a target of 50% by weight) of the resole component of the formulation. The formulation is heated to effect foaming of the mixture, and then carbonized to produce an open cell, graphitizable foam preform.

Abstract: A convertible aircraft brake assembly (10) designed as original equipment to have heat sinks comprising a steel heat sink (20) aircraft brake assembly and a carbon-carbon composite heat sink (40) aircraft brake assembly. When the aircraft brake assembly is converted from one type of heat sink to the other, the conversion is accomplished with minimal changes in component parts. The conversion can be accomplished without any changes in the piston housing (14), torque tube (12), and wheel (30) because the heat sinks include therein respective components which enable each heat sink to be utilized with the commonly used piston housing (14), torque tube (12), and wheel (30).

Abstract: The invention provides a method for producing carbon/carbon composite honeycomb structures which have not only the mechanical properties associated with carbon/carbon materials but high thermal conductivities (>200 w/m-k) as well. A honeycomb structure comprising a low-modulus pitch precursor carbon fiber composite is heated or carbonized to drive off volitiles, densified at low pressure by CVD/CVI to provide a graphitizable carbon matrix, and then heat treated to graphitize both the carbon fiber and the carbon matrix. The resulting honeycomb structure has a high thermal conductivity with an increased fiber modulus and may be used, for example, for making heat transfer devices.

Abstract: An on-line self-calibrating system where prior calibration information is updated by combining prior stored calibration information with current sensor reading information to simulate the introduction of a known calibrating sample and to generate new calibration information. A preferred embodiment of the present invention is in a laser spectral absorption system for determining the concentration of a particular gas in a gaseous sample by sensing a characteristic narrow spectral pulse in the absorption characteristics of the sample, the area or spectral integration of the pulse being proportional to the concentration of the particular gas. The disclosed technique effects on-line recalibration of the system based on current operating parameters of the system to compensate for time or usage induced degradation in system accuracy without introducing a sample of a known concentration of the gas into the system.

Abstract: A combination pressurizing valve (27) and fuel flow divider for a gas turbine is operable in three different fuel distribution modes utilizing three windows which are successively opened to control the flow distribution to the engine atomizing or start-up nozzles (23) and engine air blast or running nozzles (25) respectively by way of two fixed orifices (51, 55) in a way that satisfies the start-up flow distribution favoring the atomizing nozzles (23) as well as the need for balanced flow distribution between the different types of engine nozzles after a successful start. The first window position corresponds to an engine ignition mode and includes a range of intermediate valve spool (33, 133) positions where one outlet port (57) is open and the other outlet port (67) receives a restricted flow of fuel.

Abstract: A control arrangement for a fuel system having a fuel pump (13) for supplying fuel through a variable orifice flow metering valve (15) to an engine main fuel control (45), the control (45) controlling the fuel pressure differential across the orifice of the metering valve (15). A head sensor includes a movable diaphragm (51), a bypass valve (47) for diverting fuel from the fuel pump away from the metering valve (15), and a coupling between the diaphragm (51) and the bypass valve (47) whereby the bypass valve (47) opens and closes in response to diaphragm (51) motion. The metering valve orifice fuel pressure differential is applied across the diaphragm (51) so that a valve spool (55) may open and close to maintain the pressure differential across the metering valve (15) substantially constant. A bias spring (54) normally biases the spool (55) closed.

Abstract: A cam (23) provides a rotating guide surface (33) for the cage (30) of the roller elements (25, 26) of a bearing (22) used to support the load on the cam of an axial piston pump (11) that uses pistons (17, 18) having no shoes or slippers. The rotating guide surface (33) is provided by extending a cylindrical surface (34) from the rotating cam (23) through the inside diameter, or around the outside diameter of the rolling element cage (30), concentric to the centerline of rotation.

Abstract: A high response valve (10) has a leaf spring (25) preloaded and positioned over an orifice plate (23). The orifice plate (23) has a plurality of interleaved ridges (62, 64) and grooves (61, 63, 65) with the grooves being in continuous communication with a valve inlet (13, 19). A plurality of slits or openings (49, 51) in the aperture plate (23) are in continuous communication with a valve outlet (21), each opening (49, 51) passing through a corresponding ridge (62, 64). A pair of electromechanical transducers (27, 29), each comprising a generally cylindrical stack of piezo-electric disks having a central axis (71), actuate the valve (10). One end of each stack (27, 29) is adjustably fixed relative to the housing by adjustment screws (41, 43), and a cap (35, 37) at the other end of the stack couples the stack to a corresponding spring (25) end. Each cap (35, 37) includes a notch (39) for engaging and maintaining a corresponding spring end near the corresponding central axis (71).

Abstract: An adjustment arrangement or adjuster for a hydraulic brake actuator (5) of the type having a piston (13) which moves a preferred distance within a cylindrical bore (18) in a housing (7) between a quiescent retracted position with a preferred clearance space (25) between one piston end (10) and a brake member (2) of a heat stack (1), and an extended position with the one piston end (10) engaging and actuating the brake member (2) in response to the application of hydraulic fluid pressure, includes a return spring (19) which, upon relief of the hydraulic pressure, urges the piston (13) back from the brake member (1) engaging position to the retracted position.