Abstract: In a structure utilizing a pair of accelerometers vibrating in a direction normal to their force sensing axes, a circuit utilizing voltage-to-frequency converters is utilized to convert the analog output signals from the accelerometers to digital signals representing the translational motion and the angular rate rotation of the structure.

Abstract: This invention relates to a triangle wave generator for producing a constant amplitude triangle wave signal having a frequency proportional to an input voltage signal. The triangle wave generator is comprised of a square wave signal generating circuit to provide a square wave signal having a frequency proportional to the input voltage signal.A biased amplifier circuit is provided which has an input and an output. The input of the biased amplifier circuit receives the input voltage signal and the biased amplifier output is coupled to a switching circuit.The switching circuit is coupled to the square wave signal generating circuit to receive the square wave signal and provide a pair of square wave signals to positive and negative input terminals of a differential integrator. One of the pair of square wave signals is the complement of the other.The differential integrator provides the constant amplitude triangle wave signal which has constant amplitude and has a frequency proportional to the input voltage.

Abstract: An apparatus for inertially determining the rate of angular rotation and translational motion of a structure is provided which utilizes a pair of vibrating accelerometers vibrating along a single axis with their force sensing axis located normal to the axis of vibration and rotated 90.degree. from each other. Signals from the vibrating accelerometers can be processed to provide indications of angular rotation about two axes and translation motion about two axes. Two of the sets of vibrating accelerometers can be combined to provide a three axis inertial reference system.

Abstract: In an inertial system for sensing the angular rotation and translational motion of a structure utilizing a pair of accelerometers in a back-to-back arrangement vibrating substantially linearly along an axis normal to their force sensing axes, a mechanism utilizing a parallelogram structure is used to impart the vibratory motion to the accelerometers.

Abstract: In order to provide for accurate setting of a preload force on an accelerometer force responsive pendulum and to provide for rigid support for the pendulum, a pendulum support assembly is constructed with a flexure member that is attached at one end to the accelerometer frame. The flexure receives the preload force from a preload pin at the other end and has one pendulum axle bearing attached to it between the attachment point and the preload pin. In addition, the flexure includes a hinge portion located next to the attachment point that serves to make the flexure a statically determinate beam so that the preload force on the bearing can be accurately determined.

Abstract: To increase the effectivity of warnings and to decrease nuisance warnings in a ground proximity warning system having several modes of operation, the switching from one mode to another is done as a function of time. In addition, in a ground proximity warning system where a warning signal is generated in accordance with a predetermined relationship between flight parameters, one or more of these parameters can be varied as a function of time in order to, for example, increase the altitude above ground as a function of time from take-off that a terrain clearance warning may be generated or to decrease as a function of time, the radio altitude below which a negative take-off after a climb warning may be generated.

Abstract: The present invention relates to an impingement cooling apparatus for use in the removal of heat from a heat liberating device. The apparatus includes a housing on which the device is secured and a stack of plates fitted within the housing. One of the plates is an impingement orifice plate adjacent the housing where the device is located. The orifice plate has a region that is characterized by coolant flow impingement orifices passing therethrough. The orifice plate also has a coolant drainage return adjacent the impingement orifice region.

Abstract: This invention relates to a self-priming screw pump lubrication system. The system 10 includes a central feed tube which communicates at one end with lubricant in a reservoir or sump and at the other end to the central region of an assembly that includes a horizontally disposed rotating shaft. The shaft having thereon threaded portions of opposite pitch mounted within a pair of mating sleeves which sleeves are biased away from each other at the central region of the assembly. The other ends of the sleeves are in abutting relationship with the outer races of a pair of angular contact bearings to be lubricated. Each of the inner races of the bearings are mounted on the rotary shaft. Lubricant slingers are mounted on the rotating shaft at a point remote from the bearings and cooperate with the lubricant that has been drawn upward through the central feed tube and delivered to and past the bearings, whereupon the slingers propel the lubricant back to the reservoir for reuse.

Abstract: The present invention is directed to a fuel supply system for a fuel burner of the type that requires for proper operation an excess flow of fuel to be provided to the burner with that excess being recirculated. The fuel system further requires that sufficient fuel is added to the system to make up for that amount of fuel which is fired or burned. The fuel supply system includes a fuel pump which selectively draws from a fuel supply the make-up fuel flow and from a return path the excess fuel flow for recirculation. At any given moment all fuel flow from one inlet line and the other inlet line is positively closed.

Abstract: An electrical distribution system has parallel connected generators powered by variable speed engines. Loads connected with each generator are interconnected through an electrical distribution bus. Constant speed drives have inputs connected with the engines and outputs directly connected with the generators. The connections between the constant speed drive outputs and the generators are characterized by the absence of overrunning clutches used in prior systems. An improved electrical protective circuit senses a flow of electrical power from the distribution bus to a generator, driving the generator as a motor. If the power flow to the generator is excessive, the bus tie breaker is opened disconnecting the generator from the bus.

Abstract: This invention relates to a shorted diode protection system for a brushless alternating current generator of the type having an energizeable exciter field winding. The system includes a circuit arrangement for sensing the voltage difference across the exciter field and pairing the voltage difference with generator load current to thereby provide an output signal that falls within a predictable range of values over a normal generator load current range. The output signal is of such a nature that it falls within a higher range of values upon the occurrence of a shorted diode. Another circuit arrangement is responsive to the output signal such that whenever the output signal exceeds a preset value over the normal load current range, an output is generated that operates to cause the interruption of the exciter field.

Abstract: This invention relates to an energy absorbing ratchet for a bidirectional no-back apparatus which includes in combination a fixed support, a rotatable input member and a rotatable output member. The input member includes an input plate which has integral therewith a pair of release pins. An output plate is coupled to the output member. The input plate and the output plate have a torque transmission device coupled therebetween. The fixed support has an energy absorbing means coupled to a ratchet ring. The ratchet ring is positioned between the input and the output plate. The output plate has thereon a pair of moveably mounted pawl members for cooperative engagement with the ratchet ring to thereby engage the ratchet ring when the no-back apparatus is at rest, and whenever a backdriving load is delivered from the output member to the output plate. The pawl members are released from the ratchet ring by the cooperative engagement with the release pins upon bidirectional rotation of the input member.

Abstract: This invention relates to a slipper and swashplate cavitation erosion control and impact reduction assembly for a piston type hydraulic apparatus that includes a rotating cylinder block having at least one axially disposed bore. A piston is mounted for reciprocal movement within the bore. A fixed port plate is provided as well as a pair of different fluid pressure sources. The port plate cooperates with the rotating cylinder block to deliver alternately during two discrete and different portions of the cylinder block rotation first one of the fluid pressure sources and then the other of the fluid pressure sources to the bore and the piston. The piston has at one end thereof a slipper coupled thereto and the slipper is mounted for a sliding interface movement on a surface of a swashplate. The swashplate is nonrotatable in respect of the port plate.

Abstract: A head moving mechanism for a tape deck provides for accurate shifting of a magnetic head from one set of tracks to another by securing the magnetic head to a head carriage member which in turn is attached to the tape deck by two flexures. A solenoid secured to the head carriage member serves to move the magnetic head by means of a linkage mechanism attached to the tape deck.

Abstract: The present invention is directed to an electro hydraulic control system wherein electric current output of the control is applied to an electric force motor to position a valve spool which in turn modulates fluid flow to a device to be controlled. The valve spool, either to accommodate manufacturing tolerance or to assure zero output flow, in the neutral position, has a flow dead zone which requires a substantial valve spool travel to initiate fluid flow through the valve. In the preferred device the manual control handle modulates the current output of the electric circuit which in turn proportionately modulates the position of the valve spool. The electric circuit is provided with resistance means which are selectively inserted into the circuit to assure that sufficient output current is provided to the force motor to move the valve spool that amount necessary to initiate fluid flow upon a small movement of the control handle to compensate for the fluid flow dead zone in said valve.

Abstract: This invention relates to a resettable force limiting assembly of the ball and screw type employed in a flight control actuation system. The resettable force limiting assembly includes a force transmitting reciprocating output member drivingly carried by an actuating member mounted for rotation in a housing. A reversible torque input is mechanically coupled to the actuating member to cause the output member to move in a direction dependent upon the direction of rotation of the input. A reciprocating reaction plate is secured for rotation with the actuating member. In operating cooperation with the reaction plate is a reaction plate engagement assembly that has elements secured against rotation to the housing. The elements are disposed on either side of the reaction plate. The elements have compression springs coupled thereto to resiliently separate the elements while allowing the elements to individually move towards and away from the reaction plate.

Abstract: A self-acting automatic clearance control apparatus for a turbine of the type which includes a turbine rotor mounted for rotation in a housing, the turbine rotor having cooperatively disposed on one side thereof a nozzle and on the other side an exhaust duct, the apparatus includes a control device positioned adjacent to the turbine rotor. The control device is coupled to the nozzle and the exhaust duct. The control device is responsive to changes in dimensions of said turbine rotor as the turbine operates over a range of temperatures to thereby change the relative position of the control device in respect of the turbine rotor whereby the clearance between the nozzle and the exhaust duct in respect to the turbine rotor is maintained automatically.

Abstract: The invention relates to an automatic rigging arrangement for an actuation system wherein the rigging arrangement includes in combination a differential length feedback device that has a moveable inner member and an outer member, with the outer member secured at its ends respectively to a power drive unit and an actuator, the moveable inner member being controllingly coupled to a power drive control and secured to an actuator position feedback member of the actuator to thereby provide via the moveable member of an actuator position feedback input signal to a signal summing means associated with the power drive control. The feedback input signal being proportional to an actuator position and the signal summing means being responsively coupled to the power drive unit to receive as an input, a signal representative of a given position commanded.

Abstract: In order to provide for substantially reduced costs in acceptance testing of aircraft computers, the acceptance test system described herein includes: a group of input circuits for receiving the computer output data signals; an input circuit adapted to receive signals from the aircraft computer representing the computer input data signals; and a transmitter for transmitting the computer input data to the computer. In this automatic acceptance test system, the computer under test generates both serial and parallel input data signals for itself which are then retransmitted to the computer under test by the automatic test system.

Abstract: This invention relates to a motor control unit and a feedback arrangement to minimize the effects of backlash in a rotary output system. The system includes a source of energy. The motor control has a directional control element moveable from a null position. The motor control unit is coupled to the source of energy and to a motor which in turn is coupled to the rotary output and to a second input of a differential harmonic drive that has first and second inputs and an output. The first input of the differential harmonic drive is coupled to a rotational command input unit and the differential harmonic drive output is drivingly coupled to the moveable direction control element. In response to a given rotational command input when the second input is in an initial static position, whereupon the motor is coupled to the source of energy through the motor control unit, the rotary output is driven a precise number of revolutions dependent upon the given rotational command input.