Abstract: A burner control system includes a pump for supplying pressurized fuel through a fuel line and a signal-responsive flow valve to a burner nozzle. Also in the system is an ignition control circuit which includes an igniter operable in response to a first signal in the circuit to ignite the fuel. A flame-detecting cell in the circuit causes the termination of the first signal so as to deactivate the igniter when combustion occurs. A second or auxiliary circuit operatively connected to the ignition control circuit includes a first switch responsive to the first signal in the ignition control circuit to cause a second signal to be transmitted to the flow valve for opening the valve to allow pressurized fuel to flow to the nozzle. A second switch in the second circuit serves as an alternate circuit for transmitting the second signal to the flow valve.

Abstract: A centrifugal pump includes a housing containing an impeller mounted on a shaft which is journaled for rotation within the housing. An inlet to the housing directs fluid from a supply to one end of the impeller and axially spaced first and second volute diffusers formed around the other end of the impeller receive fluid from the impeller. The volute diffusers are of different predetermined sizes designed to handle different flowrates of fluid while producing about the same pressure head. A sleeve telescoped into the housing and surrounding the impeller may be moved between extended and retracted positions to close off and open the flow of fluid into the larger one of the volute diffusers.

Abstract: In order to facilitate construction of a compact, lightweight servoed accelerometer with capacitive pick-off, a one-piece support frame, adapted to be inserted within a cylindrical housing, is used to support a pair of capacitor plates and a lightweight longitudinally reinforced pendulum or seismic mass having a paddle on one end. Attached to the pendulum is an axle which in turn is supported between two flexures by means of jeweled pivoted bearings. Also attached to the pendulum is a torque coil which interacts with a magnetic assembly, secured to the support frame, to restore the paddle to the midpoint between the capacitor plates when the pendulum has been subjected to an acceleration force.

Abstract: In order to provide a more accurate representation of aircraft pitch attitude for use in aircraft head up display devices, a circuit for generating a computed pitch signal responds to a longitudinal accelerometer and a vertical gyroscope within the aircraft wherein the computed pitch signal is generated by adding to the gyro pitch signal a correction factor computed by subtracting the value of the computed pitch signal from an inertial pitch signal derived from the longitudinal accelerometer. In order to compensate for the effects of aircraft acceleration on the longitudinal accelerometer signal, a computed acceleration signal derived from the difference between the longitudinal accelerometer signal and the gyro pitch signal is subtracted from the longitudinal accelerometer to generate the inertial pitch signal.

Abstract: An impeller blank for a centrifugal compressor has impeller blades with inducer sections of parabolic contour extending in a generally axial direction from generally radial sections of the blades. The angle of the working surface of each inducer section with respect to a plane at right angles to the impeller axis varies inversely with diameter and with the axial dimension of the inducer section from the radial section. The inducer sections are cut to a diameter for minimum gas velocity with respect to the impeller, a function of gas flow rate and impeller speed, and are cut axially for an inlet angle which is a function of the ratio of axial to peripheral gas velocity to achieve flow nearly parallel with the working surface of the inducer section.

Abstract: A thermally actuated disconnect coupling includes a coupling shaft normally connected between a drive member and a driven member to transmit torque from the drive member to the driven member. Within the driven member, a fusible element such as a eutectic pellet supports the coupling shaft against axial movement during normal in-service use of the coupling. Providing the connection between the coupling shaft and the drive member are axially straight splines formed both on the coupling shaft and the drive member. At the other end of the coupling shaft, helical splines formed on the coupling shaft and the driven member provide means whereby torque is transmitted through the coupling shaft to driven member. The axial length of the helical splines is greater than the axial length of the straight splines.

Abstract: An on-axis, optical head-up display device, for use in fixed installations, vehicles or aircraft, utilizes a single block of transparent acrylic resin with the upper surface curved and coated to form a collimating mirror. The block itself is comprised of two major portions cemented together with a transparent bonding material wherein the resulting interface forms a combining surface. A generated image is transmitted from the focal plane of the collimating mirror upwardly through the combining surface; then it is reflected downwardly by the collimating mirror back to the combining surface which in turn serves to combine the generated image with a background view. The combined image is viewed by an observer through a back window of the block. Optical aberrations are reduced by extending the material of the block to the focal plane of the collimating mirror where an image generator is located.

Abstract: To eliminate the high frequency portion of an input signal while permitting low frequency and DC portions to pass, the electronic filter utilizes an n-1 order active network in combination with a capacitor to generate a shunt current, thereby providing a low pass filter having n-order operating characteristics. Included in the active network is an active element, such as an operational amplifier, which responds to an input signal by creating a voltage across the capacitor, resulting in a shunt current that in turn provides the desired filter characteristics. In certain special cases the n-order active filter can utilize a differentiating element in combination with n-2 order active network along with the capacitor to achieve n-order operating characteristics.

Abstract: In order to provide an electrically insulated and fluid-tight assembly for securing a current transformer to the inside of a dynamoelectric machine housing, a screw is inserted through an aperture in the machine's housing to secure the current transformer to a portion of the inner surface of the housing wherein a first insulating material is used to insulate the current transformer from the housing; a second insulator is used to insulate the screw from the housing; and an insulating cap is secured over the top of the screw. An O-ring provides a fluid-tight seal between the cap and the machine housing and a retaining ring is utilized to secure the cap over the screw's head within the machine housing. Secured to the lower part of the current transformer is a soft iron magnetic shield which is threaded to engage the screw and serves to support the current transformer.

Abstract: A hydromechanical transmission including an input shaft, an axial piston hydraulic pump assembly associated with the shaft to be driven thereby, a pivotal swash plate operatively associated with the pump for selectively varying the displacement thereof, an axial piston hydraulic motor assembly coaxial with the pump, and a floating valve plate disposed between and engaging the pump and motor. A sun gear is carried by the motor, while a ring gear is carried by the pump. A rotatable output carrier is coaxial with the shaft and carries at least one planet gear engaged with both the sun and ring gears. The output of the transmission is taken from the carrier.

Abstract: An electronic circuit is provided for regulating a three-phase generator which includes: a circuit for sensing the average of the three-phase voltages; a circuit for sensing the highest phase voltage; and a circuit for sensing the highest phase current. The output of each of these circuits is compared to reference currents which represent an average voltage setting and high phase voltage and current limits, and an error signal is generated that is integrated over time. The integrated error signal is utilized as input to a comparator circuit which generates a pulsewidth modulated signal that represents deviation from the desired operating parameters. The pulsewidth modulated signal is applied to an output amplifier circuit which in turn serves to control the current through the generator's exciter field. An exciter field current detector is connected between the output amplifier and the input of a gain and compensation circuit in order to provide a negative current feedback circuit to minimize transients.

Abstract: In order to limit the acceleration and speed of jet engine accessory equipment when a jet fuel starter is being utilized as a power source to drive the accessory equipment when the main jet engines are disconnected from the jet fuel starter, an acceleration and speed control circuit is provided to control a starter clutch that connects the jet fuel starter to the accessory equipment. The acceleration and speed control circuit compares a signal representing a predetermined maximum acceleration and speed with a signal that represents the rate of rotation of the accessory equipment and generates signals to regulate a control valve which in turn controls the starter clutch.

Abstract: In a dynamoelectric machine having a source of coolant for applying coolant under pressure to the machine housing, a coolant transfer tube is provided for transferring the coolant from the machine housing to an internal passageway in the shaft. Both the housing and the shaft are provided with bearing surfaces that allow the transfer tube, with each end configured into a journal, to rotate independently of the housing and shaft.

Abstract: An emergency hydraulic power system for aircraft which becomes operable upon aircraft engine failure includes a hot gas turbine for driving a hydraulic pump, a decomposition chamber to provide hot gas for driving the turbine, a normally unpressurized fuel storage tank, and a fuel pump for delivering fuel from the tank to the decomposition chamber. A start system includes a start fuel bottle having a cell filled with fuel and provided with a movable wall, and a cylinder of gas under high pressure which is regulated to put intermediate pressure on the movable wall and expel fuel from the cell, and also to put low pressure on the fuel tank, after a start valve is opened. Both the fuel tank and the start fuel cell communicate with an inlet conduit which goes to the fuel pump inlet, and a valve is provided to prevent start fuel from going into the fuel tank; and there is also means normally blocking communication from the start bottle and the tank to the pump inlet.

Abstract: In order to secure a copper spacer element between two wires while brazing the wires to the spacer, a brazing clip is provided with retaining members to aid in maintaining the brazing clip and the copper spacer between the wires during the brazing operation. Retention of the copper spacer element between the two wires is additionally facilitated by configuring the clip to retain the spacer element by means of spring forces.

Abstract: By utilizing a radio altimeter in conjunction with a measure of the aircraft speed, landing gear position and flap position, an aircraft terrain warning system is made possible which provides a voice warning indicating that the aircraft is too low with respect to the terrain when the aircraft is above a predetermined speed. For aircraft speeds below the predetermined speed, a voice warning is provided when the aircraft is below a predetermined altitude with the landing gear up indicating that the aircraft is too low with the gear up and when the gear is down and the flaps are not in a landing position and the aircraft descends below a second predetermined altitude a voice warning is generated indicating that the aircraft is too low with flaps up.

Abstract: In a vehicle wherein power is applied to each track or wheel through a hydrostatic transmission and control system including: a displacement control unit for regulating each transmission; a steering control valve associated with each displacement control unit for modifying the operation of the displacement control unit; and a speed and direction control unit for applying hydraulic pressure to each of the displacement control units for controlling the basic direction and speed of the vehicle; wherein the maintenance of the desired direction of operation of the vehicle is enhanced by an electronic tracking control circuit that includes: means for measuring the actual speed of each track; a phase comparator for providing a signal indicating the difference in track speeds; an integrator for providing a signal proportional to the difference in speed as measured over time; and comparator circuits responsive to the integrator for triggering a solenoid control valve connected between the appropriate steering control

Abstract: A fuel burner pumping system includes a pump having an inlet communicating with a fuel source and an outlet which communicates with a control valve assembly for regulating the pressure of the fuel supplied to the fuel burner nozzle or nozzles through a nozzle passage leading from an outlet port of a main chamber in the control valve assembly. High pressure fuel is pumped into the main chamber through a first outlet passage leading from the pump. A second outlet passage leading from the pump to the nozzle passage by-passes the control valve assembly so that air may be purged from the system when the pump initially is started. An air purging valve within the second outlet passage is movable between closed and open positions for blocking fuel flow through such passage during normal operation of the pump and for opening the second passage when the pump initially is started.