Abstract: Polarizing and locking means for a pair of mateable units including a member having a key on one unit and a member having a plurality of keyways on the other unit. A ring-shaped element selectively obstructs all the keyways but one on the associated member and the key is angularly disposed on the other member to register with the unobstructed keyway when mating the units. One of the members is moved axially and rotated to engage the key with the rear wall between the keyways for locking the units together.

Abstract: A method of making an electrical connector, which has a shell, an insert member and a wafer member, said insert member and wafer member stacked in the shell having apertures therein for receiving electrical terminals, the method including assembling the insert member with the wafer member with the apertures in the member and wafer aligned, wrapping a deformable laminate around the members, inserting the assembled members and laminate into the shell with the insert member, engaging a forward-face of the shell, then inserting a first sleeve into the shell in engagement with the laminate and applying a force to the sleeve to deform the laminate in the space between the shell and the insert member and wafer member. The deformed laminate preferably substantially fills the forward portion of the shell and is coated with a thermo-setting material which may be cured to more completely fill the forward portion of the shell. A grommet and a seal may be assembled with the insert member.

Abstract: An inductive spark ignition system for a gas turbine engine in which the switching semiconductor and other components are protected from failure under igniter plug load conditions. The ignition system includes means for positively turning off the switching semiconductor to start a firing cycle and for insuring that the switching semiconductor remains nonconducting long enough to dissipate the energy in the firing circuit. A Darlington transistor is used for switching and means are provided for limiting voltage and current in the transistor pair.

Abstract: A pair of mateable units with polarizing means for controlling mateability of the units comprising a member rotatably mounted on each of the units one of the members having an extension of predetermined shape and the other member having a recess of predetermined complementary shape for receiving the extension on the one member. The members each have a slot in one end for receiving a screw driver to rotate the members to adjusted position without removing, resetting and reassembling small components.

Abstract: A connector with a plurality of filter contact terminals having a ground wafer molded from plastic material and plated with metal and having integral spring tines for engaging the filters on the contact terminals to provide an electrical connection. The ground wafer may be seated in a cup-shaped ring made of metal and including a series of integral spring members formed in its outer circumference for engaging the shell to provide good connections for the filters.

Abstract: An electrical connector has a shell with an insert member and a wafer stacked in the shell for receiving and retaining the electrical terminals. A ribbon-like lamination is deformed in the space between the shell and insert member and between the shell and wafer to maintain the insert member and wafer assembled to one another and to the shell.

Abstract: A rate integrating device includes a torquer in open loop configuration for torquing the device to null and a load connected to the device in closed loop configuration for maintaining the device at null. The load loop includes electrical means whereby the maintenance of the device at null is controlled independent of its dynamic characteristics for increased accuracy and stability.

Abstract: An integrating angular accelerometer for measuring angular rate of a rotating body has a stationary cylindrical inertial mass supported by a low drag hydrostatic bearing concentrically in a housing rotatable relative thereto and filled with a viscous fluid. An annular channel of laminar dimensions is formed between the inertial mass and housing and a vane is arranged in the channel to block fluid flow caused by rotation of the housing relative to the inertial mass. The differential pressure in the channel at opposite sides of the vane provides a signal corresponding to the rate of rotation of the housing relative to the inertial mass.

Abstract: A voter circuit with averaging means eliminates a deadzone characteristic inherent in prior art voter circuits when unvoted or unwanted input signals are near zero. Elimination of the deadzone characteristic renders the voter usable in small signal regions.

Abstract: A capacitance to digital conversion system wherein condition sensing capacitors are arranged with reference capacitors in a circuit configuration so as to eliminate the need for an absolute a.c. voltage thereby imparting a high degree of precision to the system. Primary error sources are virtually eliminated since all operations are performed on an error signal and a single oscillator drives both sensing and reference capacitors so that frequency variations in the output of the oscillator have no effect on the accuracy of the measurement being made. Additionally, the high degree of precision is accomplished with a significant reduction in hardware.

Abstract: A speed sensor for a vehicle wheel having a rotating tone wheel and a stationary magnetic sensor with a sensing pole proximate the tone wheel teeth and a compensating pole proximate the tone wheel spaced from the tone wheel teeth. The sensing pole and compensating pole are secured to the ends of a permanent magnet in U-shaped configuration and coils connected in series opposition are wound on the sensing and compensating poles. Noise components generated in the sensing coil with the speed signal voltage due to axial misalignment and vibration of the tone wheel are cancelled by corresponding noise components generated in the compensating coil to provide a substantially noise free signal voltage corresponding to wheel speed.

Abstract: A device for providing signals corresponding to rotation of a body having a magnetic sensor with a sensing pole positioned proximate to a tone wheel rotated by the rotating body. A permanent magnet is attached to the sensing pole and a signal voltage having a frequency proportional to the speed of the rotating body is induced in a coil surrounding the sensing pole. The sensing pole is made of square loop magnetic material and is shaped and arranged to cause the magnetomotive force difference between its pole face and the tone wheel to decrease as the air gap length between them decreases, thus causing the normally large change in sensor output with air gap length variation to be substantially reduced.

Abstract: A synchro having a rotor with windings supported by a shaft for rotation through an angle of approximately 360.degree. relative to a stator in which the rotor windings are connected to external circuitry by leads each of which is formed into a coil with a straight portion extending therefrom. The leads are disposed oppositely in a hollow portion of the shaft with the coil of each of one lead encircling the straight portion of the other lead and with the straight portions of the leads extending axially of the shaft.

Abstract: A method of visually detecting defects in a printed circuit board comprising preparing a mask with a light blocking pattern corresponding to the desired printed circuit, illuminating the printed circuit board through the mask with the light of a color complimentary to the color of the printed circuit board and with the light blocking pattern in registry with the printed circuit and inspecting the printed circuit board for light reflected from defects in the printed circuit not present in the light blocking pattern on the mask. The defects are readily apparent as bright spots on a dark background.

Abstract: Apparatus for automatically eliminating a sway condition of a trailer towed by a tow vehicle. A hitch connects the trailer to the tow vehicle and has a sensor for providing signals corresponding to the hitch lateral force for operating the trailer brakes.

Abstract: A hand tool for stripping insulation from both multiconductor cables and individual insulated conductors comprising a pair of rigid members pivoted to one another at one end and having a guide post with an elongated blade mounted on the opposite end of each member with the cutting edges of the blades in the same plane and opposing one another and spaced from one another to receive the cable or conductor therebetween. A spring urges the members toward one another with sufficient force for the blades to slice the insulation at each side of the cable or conductor when the cable or conductor is inserted transversely between the guide posts at one end of the blades and moved lengthwise of the blades and to slice the insulation circumferentially when the blades are rotated around the cable or conductor. The insulation is then stripped from the cable or conductor by transverse movement of the blades axially of the conductor.

Abstract: A spiral groove bearing includes a dynamic lubricant reservoir internal to the bearing for providing a continuous flow of lubricant to the active portion of the bearing. The fluid pumping effect of the spiral groove bearing in association with a fluid pump arrangement distributes the lubricant, and the reservoir has an orifice including lubricant flow control means for applying sufficient lubricant to the bearing.

Abstract: A vertical scale indicator has an index movable relative to a scale for indicating a condition sensed by a signal condition device. The index is supported on a flexible band wound on two drums. One drum is driven directly by a servomotor responsive to signals from the signal condition device and the other drum is driven by the servomotor through spring means for providing relative rotation between the drums to accommodate rotation of the drums through different angles in accordance with the amounts of tape wound on the drums.

Abstract: A message tape for instrument display systems includes laminations of metallic and plastic materials. Messages are etched through a metallic lamination and dyes are applied through the etchings to provide color coding without introducing dimensional buildups. The dyes are retained by a plastic backing lamination. The tape has the main advantage of being useful at elevated operating temperatures and ancillary advantages of improved image quality and lighting efficiency.

Abstract: A biphase waveform is generated using a serial register of length 2N where N is the number of bits to be transmitted. Each data bit is loaded into a shift register, both directly and through an inverter. Double speed clocking provides an alternating logic level signal for each data bit and the phases of the alternating signals are combined to provide the biphase waveform.