Abstract: An improved disc brake friction pad assembly is provided with a metallic backing plate element, a friction pad element, and a noise-dampening shim subassembly positioned intermediate the backing plate element and the friction pad element.

Abstract: A hybrid brake assembly is provided with both a resin-bonded metallic friction pad element and a resin-bonded non-asbestos, non-metallic friction pad element and hydraulic cylinder/piston elements for simultaneously actuating both friction pad elements in a vehicular braking operation.

Abstract: A novel brake friction pad assembly is provided with a backing plate element, and with one or more integrally joined different friction-generating pad, noise-damping pad, and backing pad elements carried by the backing plate element, such friction-generating pad, noise-damping pad, and backing pad elements being molded using specified particulate mixture molding compositions and preferred molding method steps.

Abstract: A heating and cooling apparatus having a first gas conduit, a second gas conduit and at least one thermoelectric module. In a first embodiment, structure is provided to introduce moisture into the second gas conduit, upstream of that conduit's association with the thermoelectric module. The introduction of the moisture into the gas within the second gas conduit functions to decrease the temperature between the temperature of the gas in the first conduit and the temperature of the gas in the second conduit, thereby optimizing the operation of the thermoelectric module. In a second embodiment a plurality of thermoelectric modules are arranged in an array and positioned between the gas conduits and associated therewith. The power supplied to each of the thermoelectric modules is adjusted to correspond to an optimum power input calculated for each thermoelectric module respectively.

Abstract: A method and apparatus for providing preconditioned air to a parked aircraft is disclosed. The apparatus includes a booster unit (10) adapted for association with an existing preconditioned air unit (12). The booster unit (10) includes an auxiliary compressor (112), an auxiliary evaporator (109) and an auxiliary condenser (100 and 100A). These auxiliary elements are interconnected by suitable conduit (114, 115, and 118) and an expansion valve (116). The booster unit (10) is associated with the preconditioned air unit (12) whereby the condenser fan(s) (82 and 84) of that unit is utilized to cool the condenser(s) (100 and 100A) of the booster unit (10).

Abstract: A fluid device (pump or motor) comprises a case having a closed chamber, a rotating element mounted for rotation within the closed chamber, a reciprocating piston drivingly connected to the rotating element such that rotation of the rotating element corresponds to reciprocating movement of the piston, passages for admitting and discharging fluid to and from a cylinder in which the piston reciprocates, and scavenger pump means drivingly connected to the rotating element and operable to pump fluid out of the closed chamber at a rate greater than the rate at which fluid leaks or otherwise is metered into the interior chamber, thereby to maintain the level of fluid within the closed chamber below a predetermined level.

Abstract: A low breakout power transfer unit for transferring power between first and second hydraulic systems includes first and second pump/motor units to allow fluid flow between the first and second pump/motor units and the first and second hydraulic systems, respectively. The transfer unit includes a detection device for sensing fluid flow demand in the hydraulic systems and values for automatically isolating the pump/motor units from the hydraulic systems when the detection means senses substantially no fluid flow demands in a hydraulic system. The transfer unit includes a bypass device for each pump/motor unit for recirculating pumped fluid in excess of fluid flow demand.

Abstract: Closed center valves include a first member movable toward and away from a vent opening in the valve for respectively closing and opening the vent opening, and a second member movable toward and away from the first member for respectively closing and opening a high pressure passage through the first member. A biasing force is applied to the first member for biasing the first member toward the vent opening. Different magnitudes of force may be applied to the second member to cause the second member to move toward the first member first to close the high pressure passage through the first member while the vent opening remains closed by the first member, and then to cause the first member to move away from the vent opening to open the vent opening while the high pressure passage in the first member remains closed by the second member.

Abstract: Differential pressure sensor mechanisms include core members acted upon by pressure sensing plungers at opposite ends of the core members to cause axial movement of the core members relative to a linear variable position sensor when unequal force balances are applied to the respective plungers, and centering springs for centering the core members with respect to the sensor when equal force balances are applied to the respective plungers. The centering springs desirably flex equally in both directions to keep reversing stress levels to a minimum and are essentially unloaded in the null or lower load region of operation to minimize the possibility of induced plunger side loading in the most active and critical region of performance. Carriage members desirably support opposite ends of the core members for coaxial movement relative to the sensor.

Abstract: Linear direct drive motor includes a pair of axially spaced, relatively fixed stator poles and an armature mounted on a motor shaft for axial movement between the stator poles. The ends of the motor shaft are supported by centering springs which permit axial movement of the shaft and thus the armature relative to the stator poles. Positive stops are located between the stator and stator poles for preventing armature overtravel. Extending between the stator poles is a sleeve member which supports a ring magnet in radially spaced relation from the armature. Adjacent opposite ends of thee ring magnet are a plurality of layers of electrical coils, with the layers adjacent one end of the magnet being paired with different layers at the other end to provide redundant electrical channels and symmetric motion behavior.

Abstract: Limited angle torque motor includes a secondary magnetic flux path of relatively small cross-sectional area which increases the rotational and torque gains of the motor in a localized area about the motor null as if the magnetic air gap of the motor were substantially reduced so that when properly matched with a direct drive valve having significant valve overlap, a desired linear valve flow gain can be achieved. As the motor flux increases with applied current, the secondary flux path saturates, whereby further increases in current above a specified level are directed into the main pole structure magnetic flux path as if the secondary flux path did not exist.

Abstract: Fluid actuator includes shear pins or threaded fasteners between a rod gland and a rod gland bearing which cause the rod gland bearing to separate from the rod gland in response to a predetermined jam clearance force being applied to the rod gland bearing upon engagement of a rod deformation either exteriorly or interiorly of the actuator with the rod gland bearing to clear such rod deformation. The shear pins or threaded fasteners are sized to withstand the usual internal pressures acting on the rod gland bearing. However, whenever a piston rod deformation engages the rod gland bearing, the entire actuator force is available to shear the shear pins or threaded fasteners which frees the rod gland bearing to allow movement of the rod gland bearing with the piston rod to clear the rod deformation. A single retainer plate may be used to retain both a plurality of headed shear pins and a retaining wire for the rod gland.

Abstract: Piston rod assembly includes a composite piston rod having an entrapment ridge along the length thereof, and a non-integral metallic piston head having two separate piston head sections which are welded together in preloaded engagement against opposite sides of the entrapment ridge. The entrapment ridge has oppositely facing external tapered ramp surfaces which are engaged by correspondingly tapered internal ramp surfaces on the respective piston head sections. When the piston head sections are initially brought into engagement with opposite sides of the entrapment ridge, there is a slight gap between the inner faces on the piston head sections which determines the amount of preload force that must be applied to the piston head sections to eliminate the gap and bring the inner faces into substantial mating engagement with each other for welding.

Abstract: Actuator control system includes two parallel connected orifices between a pair of fluid passages providing communication between an actuator and a flow control valve. Relief valves in series with the respective orifices block fluid flow through the orifices at low differential pressures between the fluid passages, thereby preserving the original high pressure gain of the control valve in a region about valve null. At higher differential pressures outside the valve null region, the relief valves open to permit restricted flow through the respective orifices to reduce the pressure gain of the control valve in a region outside the valve null region, which effectively reduces the stiffness of the control valve.

Abstract: Helical spline actuator includes a pair of cylinder housings connected together in end-to-end spaced apart aligned relationship by means of a center mount. A shaft is mounted for rotation within the two housings, and has a rotatable drive member extending outwardly therefrom between the spaced apart inboard ends of the housings and out through a circumferential slot in the center mount. Pistons are axially movable within each of the housings toward and away from opposite ends of the shaft. Inboard of the pistons are helical drive members for converting axial movement of the pistons into relative rotational movement of the shaft and drive member connected thereto.

Abstract: A flow control valve assembly including a valve having open and closed positions and a limited angle torque motor having two angular rotor positions corresponding to the open and closed valve positions that are stable in the absence of an applied electrical signal. The valve motor includes magnetic pole pieces forming a concentric shell around the motor shaft that include air gaps, disposed generally parallel to the axis of rotation of the shaft. Pole blades adjacent the rotor are magnetically linked to the pole pieces by flanges disposed at the rotor ends. Two alternative minimum reluctance flux paths are provided for a permanent magnet that is mounted on the rotor with its poles transverse to the axis of rotation. The two minimum reluctance paths provide the stable rotor positions. A magnetic flux sensor disposed in or proximate one of the air gaps is employed with a relatively high frequency electrical signal to determine relative rotor and valve positon.

Abstract: An electromechanical valve assembly incorporates an electromechanical actuator, such as a limited angle torque motor or solenoid, to open or close the valve in response to a direct current or low frequency electrical signal. A valve position sensor detects the valve position in response to a second, relatively high frequency electrical signal. The actuator and sensor are electrically connected in parallel so that the valve may be actuated and the valve position may be determined through a single pair of electrical leads. The position sensor preferably includes an electrical coil having a reactance that varies with incident magnetic flux, the magnitude of which depends on valve position.

Abstract: Composite cylinder assembly includes a removable liner assembly consisting of a liner member having circumferential hoop stress windings wrapped thereabout. The ends of the liner assembly freely float on cylindrical end portions on the inner ends of end glands at opposite ends of the cylinder for sliding sealed engagement with ring seals contained in external grooves in such cylindrical end portions. Surrounding the removable liner assembly in radially spaced relation therefrom is a composite outer wall portion having opposite ends threadedly connected to the end glands radially outwardly of the removable liner assembly, whereby disconnecting the ends of the outer wall portion from the end glands will permit removal of the liner assembly as well as the liner seals and outer wall portion for refurbishment and/or replacement as desired.

Abstract: Landing gear mechanism includes a variable area orifice to obtain the desired rebound damping of the landing gear mechanism during landing, and one or more check valve assemblies that operate in conjunction with the variable area orifice to provide the desired controlled instroke of the landing gear mechanism during landing. Also, the landing gear mechanism is provided with a relief valve assembly that permits bypass flow at a pre-set pressure drop only during an intermediate portion of the instroke of the landing gear mechanism to attenuate severe bumps and the like without adversely affecting the controlled instroke and rebound damping of the landing gear mechanism during landing.

Abstract: Fluid actuator includes a piston rod comprised of a wound filamentary composite structure to provide an extremely light weight, relatively low cost, envelope efficient design. Attached to the piston rod are one or more non-integral piston heads which are preloaded against one or more ramp surfaces on the exterior of said piston rod. A pair of oppositely facing ramp surfaces may be formed on the piston rod by interspersing filler means between the piston rod fiber layers. Another ramp area may be formed by providing an external groove in the piston rod which is engaged by longitudinally split support shoes that provide an attachment surface for a detachable piston head. An internal ramp may also be provided on the inner diameter of the piston rod adjacent the axial outer end thereof for mating engagement by a conically ramped exterior surface on an internal metal stud used to attach a rod end assembly to the axial outer end of the piston rod.