Abstract: A non-inverting, direct current amplifier stage is cascaded into an integrator stage to form a two stage tuned network (10) having a single input junction common to both stages. The network provides independent adjustment of center frequency, bandwidth and voltage gain. The insertion of a positive feedback loop between the stages provides a very narrow bandwidth network (10'). The addition of back-to-back zener diodes between the common input node and ground converts the network into an oscillator (10").

Abstract: Apparatus for eliminating beamsplitter generated optical aberrations in a pupil concentric optical system providing a plurality of spatially separated images on different focal planes or surfaces (30, 56). The system employs a buried surface beamsplitter (40, 40') having spherically curved entrance (42) and exit faces (44, 54, 74, 76) which are concentric to a system aperture stop (10) with the entrance face being located in the path of a converging light beam (34) directed thereto from an image forming objective element (12) which is also concentric to the aperture stop.

Abstract: Method and apparatus for determining the focal axis (26) of an asymmetrical antenna (14) such as an offset paraboloid reflector whose physical rim (15) is not coincident with the boundary of the electrical aperture but whose focal point is known. A transmitting feed horn array (34) consisting of at least two feed horn elements (36, 38) is positioned asymmetrically on either side of an estimated focal axis (40) which is generally inclined with respect to the boresight axis (12) of the antenna. The feed horn array (34) is aligned with the estimated focal axis (40) so that the phase centers (CP.sub.1, CP.sub.2) of the two feed horn elements (36, 38) are located on a common line (42) running through the focal point (F) orthogonally with respect to the estimated focal axis. RF circuit means (44) are coupled to the feed horn elements for generating RF electric field components which are directed to the offset antenna (14) whereupon sum and difference radiation far field patterns (.SIGMA., .DELTA.

Abstract: A counter-rotating machine, such as a positive displacement pump having a pair of meshed, non-contacting helical screws (10,12), subjects its rotating members to axial and radial thrust forces when used for such purposes as compression of liquid or gaseous phase fluids while transporting them through a pump cavity (11,13). Each helical screw (10,12) has a shaft (17,17') which is actively suspended at opposite ends (11a,11b) of the pump cavity by a servo-controlled magnetic bearing assembly (19) and a servo-controlled rotary drive motor (20). Both bearing assemblies and drive motors are mounted on the outside of the pump cavity (11,13). Opto-electric angular position sensors (250) provide synchronization between radial orientation of the drive motors. The bearing assemblies and drive motors conjugately provide axial stabilization and radial centering of the helical screws during volumetric compression of aspirated liquid or gaseous phase fluids.

Abstract: A pair of generally coaxial mutually rotatable cylindrical outer ring members (34, 36) are held in spaced apart relationship by three parallelogram shaped relatively thin, flexible, flat planar spring elements (48, 50, 52) which are substantially inextensible in length and are joined to the inside of the outer ring members and held in position by arcuate inner ring segments (38, 40 . . . 46), three for each outer ring member, which respectively span an arc of substantially 120.degree.. The parallelogram shape of the spring elements (48, 50, 52) provides a slanted interconnection between the outer ring members (34, 36). The direction of slant, moreover, determines in which direction the spring elements (48, 50, 52) can flex or bend unidirectionally to relieve the compression stress imparted thereto by any mutual angular rotation of the outer ring members (34, 36).

Abstract: A multi-pinhole aperture lead screen (22) forms an equal plurality of invisible mini-images having dissimilar perspectives of an x-ray and gamma-ray emitting object (ABC) onto a rear-earth phosphor layer (24) which, in turn, provides visible light mini-images directly into a visbile light image intensifier (26). A viewing screen (34/48) having an equal plurality of dissimilar perspective apertures distributed across its face in a geometric pattern identical to the lead screen, provides a viewer with a real, pseudoscopic image (A'B'C') of the object with full horizontal and vertical parallax. Alternatively, a third screen (34) identical to the viewing screen (48) and spaced apart from a second visible light image intensifier (42), may be positioned between the first image intensifier (26) and the viewing screen (48), thereby providing the viewer with a virtual, orthoscopic image (A"B"C") of the object (ABC) with full horizontal and vertical parallax.

Abstract: A thermal switch for controlling the dissipation of heat between a body (20), acting as a heat source, and a heat sink (22). The thermal switch is comprised of a flexible bellows (12) defining an expansible vapor chamber for a working fluid located between an evaporation and condensation chamber (16, 14). Inside the bellows (12) is located a coiled retaining spring (54) and four axial metal mesh wicks (46, 48, 50, 52) two of which (46, 48) have their central portions located inside of the spring (54) while the other two (50, 52) have their central portions located between the spring (54) and the side wall of the bellows (12). The wicks are terminated and are attached to the inner surfaces (56, 58) of the outer end walls (60, 62) of evaporation and condensation chambers (14, 16) respectively located adjacent the heat source (20) and heat sink (22). The inner surfaces of the end walls furthermore include grooves (64, 66) to provide flow channels of the working fluid to and from the wick ends.

Abstract: An electrical RF signal amplifier for providing high temperature stability and RF isolation and comprised of an integrated circuit voltage regulator (26), a single transistor (22), and an integrated circuit operational amplifier (24) mounted on a circuit board (80) such that passive circuit elements (92) are located on side of the circuit board while the active circuit elements (22, 24, 26) are located on the other side. The active circuit elements are embedded in a common heat sink (70) so that a common temperature reference is provided for changes in ambient temperature. The single transistor (22) and operational amplifier (24) are connected together to form a feedback amplifier powered from the voltage regulator (26) with transistor (22) implementing primarily the desired signal gain while the operational amplifier (24) implements signal isolation. Further RF isolation is provided by the voltage regulator (26) which inhibits cross-talk from other like amplifiers powered from a common power supply.

Abstract: A flashlamp drive circuit 10 using an unsaturated transistor Q1 as a current mode switch to periodically subject a partially ionized gaseous laser excitation flashlamp 20 to a stable, rectangular pulse of current from an incomplete discharge of an energy storage capacitor C1. A monostable multivibrator MV1 sets the pulse interval, initiating the pulse in response to a flash command by providing a reference voltage to a non-inverting terminal of a base drive amplifier AV1; a tap on an emitter resistor R2 provides a feedback signal sensitive to the current amplitude to an inverting terminal of amplifier AV1, thereby controlling the pulse amplitude. The circuit drives flashlamp 20 to provide a square-wave current flashlamp discharge.

Abstract: Two mutually coherent light beams (50, 58) formed, for example, from a single monochromatic light source (32) are directed to a reflecting surface (20) of a rotatable object (18), such as a mirror, where they are reflected into imaging optical lens (10) having a focal plane optically at infinity whereby a series of interference fringes (14) will be formed in the focal plane (12) which will translate linearly thereacross in response to angular rotation of the object. Photodetectors (22, 24) are located adjacent the focal plane to detect the fringe translation and outputs a signal in response thereto which is fed to a signal processor (30) which is adapted to count the number of fringes detected and develop therefrom a measure of the angular rotation and direction of the object.

Abstract: During a distress call, a distress location transmitter 10 generates a high frequency carrier signal 40 that is modulated by a predetermined distress waveform characteristic 29. The classification of user associated with the distress call is identified by periodically interrupting modulation 42; user classification is determined by the repetition rate of the interruptions, the interruption periods, or both.

Abstract: A hand-held guide 50 for manually positioning a workpiece 58 between the anvil rib 25 and tool 9 of a hot die stamping press. A groove completed by interchangable cover plates 60, 70, 70' attached at one end of the guide conforms to a cross-sectional dimension common to similar workpieces and, with a force fit, retentively holds each of the workpieces.

Abstract: A long lifetime Stirling cycle cryogenic cooler particularly adapted for space applications comprised of a compressor section (10) centrally aligned end to end with an expansion section (12) and respectively including a reciprocating compressor piston (14) and displacer (16) radially suspended in interconnecting cylindrical housings (18, 20) by active magnetic bearings (26, 28, 30, 32) and having adjacent reduced clearance regions (82, 84, 108) so as to be in non-contacting relationship therewith and wherein one or more of these regions operate as clearance seals. The piston (14) and displacer (16) are reciprocated in their housings (18, 20) by linear drive motors (48, 52) to vary the volume of respectively adjacent compression and expansion spaces (44, 46) which contain a gaseous working fluid and a thermal regenerator (95) to effect Stirling cycle cryogenic cooling.

Abstract: An automatic thermal switch to control heat flow includes a first thermally conductive plate 2, a second thermally conductive plate 25 and a thermally conductive switch saddle 1 pivotally mounted to the first plate 2. A flexible heat carrier 27 is connected between the switch saddle 1 and the second plate 25. A phase-change power unit 9, including a piston 13 coupled to the switch saddle 1, is in thermal contact with the first thermally conductive plate 2. A biasing element 21 biases the switch saddle 1 in a predetermined position with respect to the first plate 2. When the phase-change power unit 9 is actuated by an increase in heat transmitted through the first plate 2, the piston 13 extends and causes the switch saddle 1 to pivot thereby varying the thermal conduction between the first and second plates 2 and 25 through the switch saddle 1 and flexible heat carrier 27.

Abstract: A linear magnetic bearing includes a stator member (16) stationary relative to x, y and z axes and having a longitudinal axis on the z axis as well as a member (15) longitudinally translatable relative to said axes. The translatable member (15) is controlled to have a longitudinal axis coincident with the z axis. Permanent magnets (36 and 37) on one of the members positions the translatable member (15) in a plane defined by the x-y axes relative to the stationary member (16). The position of the translatable member (15) is sensed by sensors (41 and 42) relative to the stationary member (16) in the plane defined by the x-y axes. Electro-magnets (38 and 39) on one member (23) responds to the sensor (41 and 42) to center the longitudinal axis of the translatable member (15) on the z axis. First low reluctance magnetic flux paths for the permanent magnets (36 and 37) exist through both of the members and a radial air gap (32, 33, 34 and 35) between the members.

Abstract: In a method of and apparatus for damping nutation of a spinning spacecraft (10), spin axis attitude disturbances are substantially reduced by controlling at least one nutation damping gas thruster (18) to fire with non-uniform gas pulses. During the beginning of a nutation control sequence, the duration of successive gas pulses is gradually increased (up pulsed) from zero to a predetermined maximum duration. The duration of successive pulses is then maintained constant for a time period. Finally, at the end of the nutation control sequence, the duration of successive gas pulses is gradually reduced to zero (down pulsed). Up pulsing of the gas thruster (18) is initiated in response to a predetermined maximum nutation angle measured by an accelerometer (20). Down pulsing of the thruster (18) is initiated in response to a predetermined minimum nutation angle. The number of variable and constant duration gas pulses delivered by the thruster (18) depends upon the mass distribution of the spacecraft (10).

Abstract: A process for machining glass by placing a rotating carbide working surface under minimum pressure against an area of glass to be worked and concurrently wetting the region between the working surface and the area of glass with a lubricant consisting essentially of a petroleum carrier, a complex mixture of esters and a complex mixture of naturally occurring aromatic oils.

Abstract: A magnetic bearing assembly (10) has an intermediate rotatable section (33) having an outer cylindrical member (30) coaxially suspended by a torsion wire (72) around an axially polarized cylindrical magnet (32). Axial alignment between the pole faces (40-43) of the intermediate section (33) and end surfaces (50-53) of opposed end bells (20, 22) provides a path of least reluctance across intervening air gaps (60-63) for the magnetic flux emanating from magnet (32). Radial dislocation increases the reluctance and creates a radial restoring force. Substitution of radially polarized magnets 107 fixed to a magnetically permeable cylinder (32') and insertion of pairs of armature coil windings (109-112) between the cylinder pair (33') provides an integral magnetic bearing and torsion motor (100) able to provide arcuately limited rotational drive.

Abstract: A variable speed drive wherein a first embodiment is comprised of a pivotally mounted prime mover (10) coupled to a rotary fluid output device (58), such as a fan or pump, through a variable and fixed pulley drive arrangement (50 and 52) wherein the pivotal position of the prime mover (10) and accordingly the pitch diameter of variable pulley means (50) is controlled in accordance with fluid motor means (26, 28) coupled to the prime mover (10) and which is actuated in response to a fluid feedback control signal derived from a sensed output of the rotary fluid output device (58). The pivotal motion of the prime mover (10) imparts an arcuate motion to the variable pulley means (50) which effects a speed variation of the rotary fluid output device (58) in accordance with the variation of the pitch diameter ratio of opposing variable and fixed pulley means (50 and 52).

Abstract: An apparatus for processing multidimensional data with strong spatial characteristics, such as raw image data, characterized by a large number of parallel data streams in an ordered array, comprises a large number (e.g. 16,384 in a 128.times.128 array) of parallel processing elements operating simultaneously and independently on single bit slices of a corresponding array of incoming data streams under control of a single set of instructions. Each of the processing elements comprises a bidirectional data bus in communication with a register for storing single bit slices together with a random access memory unit and associated circuitry, including a binary counter/shift register device, for performing logical and arithmetical computations on the bit slices, and an I/O unit for interfacing the bidirectional data bus with the data stream source.