Abstract: The backlash spring of a fuel control linkage is enclosed by an elastomeric sleeve which absorbs the energy of multiple resonant modes stimulated in the spring by vibratory fields. Deflections of large amplitude in the spring are minimized thereby. The sleeve has a plurality of ribs which extend axially therein and which provide an interference fit with the coils of the spring. The sleeve ribs contact as many of the spring coils as possible but minimize interference of the sleeve with the motion of the spring during the normal articulation thereof.

Abstract: In a fuel control, the body of a feedback resolver is isolated from vibratory fields within a housing in which it is mounted while maintaining alignment of its gear with a fuel control linkage. The resolver is isolated by disposing a first means radially about the feedback device, disposing a second means between the bottom of the feedback device and the housing and disposing a third means at the top of the housing, the means at the top of the housing and at the bottom of the housing being compressed such that the resolver maintains its axial relationship with the fuel control linkage while isolating the resolver from vibratory fields encountered within the housing.

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: 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: Fuel flow to the burner (10) of a gas turbine engine (15) is turned on and off by a minimum pressure valve (60) controlled by a fluid pressure operated sequence valve (110). The sequence valve includes a valve element (125) set by the pressurization thereof with fuel discharged from a pump (35). The setting of the sequence valve element (125) is maintained by a fluid latch also energized by fuel discharged from the pump whereby no complex linkages or electric motors are required for the setting of the sequence valve and the maintenance of such setting.

Abstract: A flow control device includes metering and pressure regulating elements (70 and 95) disposed one within the other and movable independently of one another for accurate maintenance of a constant pressure drop across the metering valve at a fixed temperature. Bimetallic elements (145) adjust the position of the pressure regulating element in response to the temperature of the fluid to compensate for variations therein. The pressure regulating valve element is grounded to the housing (10) of the flow control device in part for ease in adjusting the preload of a spring (130) which balances the pressure regulating element against fluid pressures applied to opposite ends thereof. The metering element is positionable by the controlled application of servo fluid to a single end thereof.

Abstract: An improved optical transducer includes optical transmitter and receiver heads and an encoder plate movable therebetween on channel-shaped tracks integral in part with an inner housing. The encoder plate, and optical heads are disposed in an optical fluid which minimizes light refraction between those optical components, cushions against shock and vibratory loading, and lubricates the encoder plate tracks. The transducer includes an input shaft connected to the encoder plate by means of a coupling which isolates the encoder plate from misalignments of the input shaft and eliminates free-play in the connection between the encoder plate and input shaft, thereby eliminating backlash in the reciprocation of the encoder plate for improved transducer accuracy.

Abstract: A wash filter for tapping and filtering a portion of fluid in a moving stream has a plug mounted coaxially in a conduit receiving the stream. The plug includes a bullet-shaped nose similar to that in a conventional wash filter for accelerating the fluid through an annular passageway adjacent the conduit wall, and a porous frusto-conical screen or mesh body portion downstream of the nose and through which a portion of the accelerated fluid is tapped and filtered. Suspended particles in the fluid are driven toward the conduit wall by the plug nose while an inwardly located portion of the accelerated fluid passes inwardly through the porous screen and then through a base of the plug into a separate outlet line arranged coaxially of the conduit.

Abstract: A fluid-operated apparatus receiving an input pressure signal exhibits a hysteresis or deadband effect by responding to an increasing pressure signal at a first level and a decreasing signal at a second and lower level. The apparatus includes a spool valve to which the input pressure signal is applied at one end of the spool. The opposite end of the spool having a given cross sectional area projects into a pressure chamber and contacts the poppet of a poppet valve held closed by a regulated pressure in opposition to forces produced by the spool. The seat of the poppet valve surrounds an opening into the pressure chamber so that the regulated pressure is admitted into the pressure chamber when the spool pushes the poppet open.

Abstract: An immersed electromagnetic torque motor having a movable flapper is protected against the accumulation of contamination in magnetic gaps of the motor and the resulting jamming of the motor by coating the motor with a lacquer or other fluid-impermeable material and mounting the motor in a blind fluid chamber from which the flapper projects. An aperture is provided in the coating at a low flux area on the exterior of the motor to admit the immersing fluid for purposes of mechanical damping and, at the same time, to restrict the migration of fluid and contaminants toward magnetic gaps within the torque motor.