Abstract: A gas turbine engine comprised of a gas generator in flow series arrangement with a free turbine is provided, that includes a bleed port disposed between the gas generator and the free turbine. The flow of hot gas through the free turbine is controlled by a valve operably disposed in a duct downstream of the bleed port. The gas turbine engine can rapidly change its power output by first bleeding a portion of the hot gas exiting the gas generator overboard, and then increasing or decreasing the amount of bleed flow, thereby producing rapid changes in the free turbine's output.

Abstract: The closed circuit, pump-back adaptive braking system (10, 110, 210, 310, 410) includes a slave isolation valve mechanism (30, 30', 30", 130, 330, 330') which has a valve member (34, 34', 34", 134, 334, 334') that permits master cylinder (12) generated hydraulic braking pressure to oppose pressure received from the pump (23) of the braking system (10, 110, 210, 310, 410) in order to prevent displacement of the valve member (34, 34', 34", 134, 334, 334') when the pump (23) is not operating. When the pump (23) of the system (10, 110, 210, 310, 410) is operating, the valve member (34, 34', 34", 134, 334, 334') is displaced to isolate substantially the master cylinder (12) from an electrically actuated valve mechanism (40, 40') during operation of the adaptive braking system (10, 110, 210, 310, 410).

Abstract: The hydraulic actuation system (10) utilizes efficiently stored hydraulic pressure to effect a higher final pressure in the system (10) for a parking brake application. The system includes a pump (12) which communicates separately with accumulators or pressure storage mechanisms (20, 30) isolated from one another. A first accumulator (20) communicates with a first three-position apply and release valve mechanism (40) that can communicate via an apply hydraulic line (26) with a second two-position apply valve mechanism (50). The second accumulator (30) communicates with the second apply valve mechanism (50). The second apply valve mechanism (50) communicates the apply hydraulic line (26) with apply lines (55, 63, 73) and at least one brake (60, 70) that is hydraulically actuated for a parking brake application. The brake (60, 70) includes a release hydraulic line (62, 72, 49) which communicates with the first apply and release valve mechanism (40).

Abstract: Structure for caging a return spring of a master cylinder to define limits for an operational chamber. The structure includes a first cylindrical member which engages a first piston and a second cylindrical member which engages a second piston with the return spring being located between the first and second cylindrical members. A stud which has an irregular shaped end member is retained in a groove in the second piston by the second cylindrical member and mated with a head member to define the limits for the return spring between the first and second cylindrical members and correspondingly the maximum size of the chamber within a bore of a master cylinder.

Abstract: This invention relates to a solution or plasticized composition comprising one or more polyanilines, and one or more solvents capable of dissolving said polyanilines.

Abstract: A closed loop fiber optic gyro features signal processing wherein square wave phase modulation is added to a modulation drive signal after overflow logic so that the square wave modulation will not cause a phase modulation ramp to exceed overflow/underflow logic limits. The arrangement is such that the phase modulation causes a retrace with each modulation period when the amplitude of the ramp is within predetermined limits. The square wave amplitude from a cycle immediately after a retrace is considered as errant data that should be excluded from a phase nulling loop. Thus, the phase nulling loop has more accurate input data so that feedback will be accomplished more effectively for improved gyro performance.

Abstract: A cover (10) of integral construction for an air bag comprising: a panel (20) and a hinge (26) formed in a first side (28) of the cover (10) for enabling the panel to rotate thereabout after the panel separates from a seam on the opposite side of the panel in response to forces imparted thereto by an expanding air bag. The seam includes stress enhancing features for increasing stresses in the material causing same to tear and separate. These stress enhancing features includes a laterally extending narrow first portion (42), a closely spaced laterally extending narrow second portion (44) and a thin bridge (46) joining the first and second portions (42,44). The first portion, second portion and bridge are relatively movable one to the other so as to generate in the material at least two zones of increased tensile stress and at least two zones of increased compressive stress sufficient to cause the material to tear.

Abstract: A centrifugal compressor impeller for gas turbine engines designed to efficiently operate at both part-speed and full speed design points includes slanted vanes in a secondary air inlet to the impeller. The vanes are tangentially slanted in the direction of rotation of the impeller to preferentially augment airflow into the impeller at maximum speed, while at part-speed discouraging airflow out of its impeller through the secondary inlet.

Abstract: A fuel control system for accurately controlling the fuel flow rate to a gas turbine engine during the initial stages of startup is provided. The fuel control system has a novel, closed control loop that measures the actual fuel flow rate to the primary nozzles of the engine, and uses this measurement to trim the commanded fuel flow rate signal generated by preprogrammed schedules in the engine's electronic control unit. By the novel arrangement of proportional and integral controllers, the fuel control system maintains a forward path gain of unity while permitting the independent adjustment of the gain of the controllers to achieve the system stability and response necessary for quick correction of fuel flow rate errors.

Abstract: This invention relates to cyclic diamides that are readily polymerized to form poly(terephthalamides). The resulting poly(terephthalamides) have high crystallinity, high temperature capabilities, dimensional stability, low moisture sensitivity, and solvent and chemical resistance.

Abstract: The invention relates to secondary power system apparatus and method for use aboard aircraft in place of conventional auxiliary power units (APU's) and emergency power units (EPU's). The invention integrated power unit (IPU) performs the function of both an APU and an EPU, while avoiding the use of hazardous monofuels. The IPU includes a turbine engine operable on pressurized ambient air, or on pressurized stored air, along with jet engine fuel. The structure of a combustion chamber for the engine which is able to use pressurized air from two separate sources; of a control able to selectively operate the engine as an EPU, as an APU, and to effect operating transition from EPU to APU; and of a complete secondary power system with the IPU are all disclosed.

Abstract: The caliper support key (40) provides a low spring load/high damping support for a caliper (12) mounted on a support member (14). The caliper (12) includes at each circumferential side a recess (20) which may receive a protrusion (16, 18) from the support member (14). At one side of the caliper (12), the support key (40) is located between the protrusion (16) and recess (20). The support key (40) comprises a generally H-shaped key support member (40) receiving at one side thereof the protrusion (16) and the other side a stepped opening (49) defining portions of a first (50) and a second (52) cavity. A plunger (60) of the caliper support key (40) engages a surface (21) of the recess (20) in the caliper (12) and extends through the first cavity (50) and into the second cavity (52) with a small clearance (72) therebetween. A composite sealing ring ( 75) is disposed about the plunger (60) and engages the surface of the first cavity (50).

Abstract: A composite has a magnesium base metal matrix and a reinforcing phase. The composite is produced from a charge containing a rapidly solidified magnesium base alloy and particles of a reinforcing material present in an amount ranging from about 0.1 to 50 percent by volume of the charge. Ball milling the charge energetically enfolds metal matrix material around each of the particles, while maintaining the charge in a pulverant state. Consolidation of the charge provides a mechanically formable, substantially void-free mass.

Abstract: A torque loop decoupler decouples a torque loop from a speed loop to allow only the speed loop to react to small, rapid changes in engine speed. The torque loop decoupler calculates a compensation signal and adds the compensation signal to a control signal of the torque control loop. The compensation signal keeps the control signal constant during small, rapid changes in engine speed. The compensation signal is calculated as the partial derivative of turbine torque with respect to changes in engine speed multiplied by a signal indicative of small, rapid changes in engine speed.

Abstract: A laminate which has improved dimensional stability may be prepared by impregnating a reinforcing substrate such as a woven glass cloth with an epoxy resin system having a relatively high molecular weight, in excess of about 850, in the presence of a curing agent followed by curing, pressing and post-baking substrate to form the desired laminate board. The variation in this dimensional stability can also be improved by utilizing a B-stage substrate which has been cured to a lower flow percentage.

Abstract: A VHF radio (10) which includes an adjustable antenna (20) formed from a component (28) shaped like an open helical compression spring which engages and can be screwed into a metal supporting collar (40) for tuning the antenna (20). An elongated plastic or rubber cylindrical member (30) is connected to the metal collar and surrounds at least a portion of the helical member (28). An end cap (32) is provided for closing the other end of the cylindrical member (30).

Abstract: The brake disc annular drive insert (20, 30, 50) comprises a single (20, 50) or two-part (30) generally cylindrical member with radially extending flanges (26, 36, 46, 56) at opposite axial ends thereof. The drive insert (20, 30, 50) includes a generally cylindrical body (22, 32, 52) having an opening (21, 31, 51) at one side thereof which extends diametrically into the body (22, 32, 52) and terminates at a point between the center of revolution (A) of the body (22, 32, 52) and an outer surface of the body (22, 32, 52). The opening (21, 31, 51) in the body (22, 32, 52) extends to an inner surface (24, 34, 54) of the body (22, 32, 52) to provide a generally rectangular opening (21, 31, 51) for receiving a spline (8) of a torque tube (6). The flanges may comprise either generally annular flanges shaped complementary with the generally cylindrical body and also may be truncated at a side opposite the opening in the body.

Abstract: A semipermeable membrane suitable for reverse osmosis applications is prepared by interfacially reacting on a support an aromatic polyamine containing at least three and, preferably, four aromatic nuclei with a polyfunctional amine-reactive compound such as an aromatic polyacyl halide.

Abstract: A real time electronic engine control system is disclosed and includes a method of an apparatus for preventing overflow during a fixed point arithmetic operation. Each of two input numbers is divided by the same fixed number to obtain quotients of the input numbers and the arithmetic operation is then performed on the quotients of the input numbers to obtain a resultant number. The resultant number r from the arithmetic operation is compared to maximum (p) and minimum (q) register overflow values and the value of r is selected if p>r>q, while the value p is selected if r.gtoreq.p, and q is selected if r.ltoreq.q. Finally, the selected one of the compared numbers is multiplied by the fixed number to provide the result of the computation.

Abstract: A composite includes granules of Type II superconducting material and granules of rare-earth permanent magnets that are distributed in a binder. The composite is a two-phase structure that combines the properties of the superconductor and magnets with the flexibility and toughness of a polymeric material. A bearing made from this composite has the load capacity and stiffness of a permanent magnet bearing with added stability from a Type II superconducting material.