Abstract: A point focus radiation concentrator using two linear echelon surfaces crossed at approximately 90 degrees with the two linear echelon surfaces having a generally cylindrical shape with a radius of curvature approximately equal to the focal distance. The two echelon surfaces may be formed on separate sheets positioned in close proximity to each other or may be formed on opposite sides of a single sheet. The cross section of the curved concentrator surface may be circular or other aspherical shape, such as parabolic, ellipsoid and hyperbolic.

Abstract: An electromagnetic device having an armature mounted in the gap of a ferromagnetic core for selective contact of either of opposed pole faces. A source of latching flux retains the armature in contact with either of the pole faces while a flux return bracket conducts flux between the armature and the source of latching flux. The source of latching flux has a surface area perpendicular to the flux path greater than the length along the flux path creating a low reluctance path for a portion of the operating flux.

Abstract: A control system adapted to control a plurality of transformer relays. An electrical isolation network is coupled to each of a plurality of transformer relays, having a pair of common control lines and providing electrical isolation for each of the plurality of transformer relays. A switch is coupled to the electrical isolation network and is coupled in parallel to the plurality of transformer relays providing selection of state of all of the plurality of transformer relays. The electrical isolation network may also provide control, as e.g. unidirectional current flow, for selecting a state of each of the plurality of transformer relays. In a preferred embodiment the electrical isolation network includes an array of diodes.

Abstract: A control system for a stepper motor utilized in positioning a transducer in relationship to a plurality of parallel tracks on a record media. Dual closed loop feedback systems are provided. A current control circuit is provided having a high output impedance and a voltage control circuit is provided having a low output impedance. A switch may select the control sensor when the transducer is making coarse adjustments in position and may select the voltage control sensor when the transducer is making fine adjustments in position. A seamless switchover may be achieved where the voltage control sensor has a time constant which matches the time constant of the stepper motor. Performance is further improved by providing an impedance cancellation circuit which eliminates the internal resistance of the motor in order to quickly damp motionally induced emf of the motor.

Abstract: A device for slowing down the movement of the armature within a solenoid comprising a resilient container having a predetermined internal volume, and a dilatant material filling the container which material has as one of its properties at ambient temperatures, a non-resilient deformation when subjected to slow steady state stress, and a highly resilient resistance to deformation when subjected to rapid shock-like stress, whereby the container is connected to the solenoid in a manner affording its compression as the armature moves within the solenoid.

Abstract: A tool for applying fasteners to fasten an article to the workpiece. A compressible foot is provided to limit the drive distance of a plunger to position dependent upon the thickness of the article. A drive groove in the tool provides support for the fastener until it is driven into the workpiece. The fastener may be a plastic staple and multiple driving strokes may be used to drive the staple into the workpiece. A retainer activated by the compressible foot may be utilized to prevent the advancement of the next staple to the drive position while multiple drive strokes are being used.

Abstract: A control system for a brushless direct current motor providing linear closed loop speed control when the motor is operating near its desired speed and providing pulse width modulation closed loop speed control when the motor is not operating near its desired speed. A current sensing feedback loop is provided to drive the transistor linearly controlling the electronic commutation of the motor into pulse width modulation when the current through the motor exceeds a predetermined value. An inductor may be coupled in series with control transistor and positive feedback may be supplied to the current sensor.

Abstract: A system adapted to remotely control a transformer relay. The load switch of a transformer relay is controlled by controlling the direction of current flow in the secondary winding. A switch module is coupled with two wires to the secondary winding of the transformer relay providing a unidirectional current flow above a predetermined threshold in the secondary winding in response to a control signal. The unidirectional current flow may be selectively controlled in either direction or may be only purely unidirectional. A control module is then coupled to the switch module momentarily producing the control signal in response to an external stimulus. The switch module, the control module, or both draw a quiescent current from the secondary winding of the transformer relay when the switch module is not activated. The quiescent current is of an amount which is less than the predetermined threshold.

Abstract: A pressure sensitive apparatus for producing electrical signals on two electrodes having a layered structure consisting of a conductive layer, a piezoelectric polymer film layer, an electrode layer, an insulating layer, another electrode layer, another piezoelectric polymer film layer, and another conductive layer. The layered structure may be constructed from an insulating layer sandwiched between two piezoelectric polymer films each having an electrode on one surface thereof and having a conductive plane on the other surface thereof disposed on each side of the insulating layer with the electrodes in closest proximity to the insulating film. Further, support substrates may be disposed on each side of the piezoelectric polymer films, the support substrates having an opening where the electrodes are located.

Abstract: An electromagnetic device having a gap area for conducting operating flux has a source of counter flux proximate the gap for confining operating flux to the gap area.

Abstract: A composite magnetic head adapted to record and read records to and from a record carrier particularly suited to a multitrack record carrier, and more particularly suited to a multitrack magnetic tape. The composite magnetic head may be moved transversely with respect to the direction of movement of the record carrier so that head alignment with any one of multitracks of the record carrier may be achieved. The record carrier contacts the head assembly defining a scrub surface. A yoke is provided supporting a ferrite core containing an effective gap which permits the head to be physically mounted with respect to the record carrier.

Abstract: An apparatus for providing a time-controlled output based primarily upon a primary time source and secondarily upon a secondary time source, the secondary time source counted down to the desired frequency of the time-controlled output. A sensor supplies a control circuit which outputs the primary time source signal when the primary time source is operative, and the secondary time source signal when the primary time source is not operative. The output of the control circuit then resets the appropriate segment of the secondary time source counter in order to synchronize the time-controlled output for the primary time source when the primary time source is operative.

Abstract: The supervised conductive loop comprises a plurality of switch elements connected in series with a DC current source. Encoder modules are located in parallel with each of the switch elements. The encoder module comprises an oscillator and an impedance element. When a switch element is opened, the oscillator associated with that switch is energized and places an AC signal on the loop. The frequency of each oscillator uniquely identifies the associated switch element. The impedance element, formed by a resistor and a capacitor, is used both as a filter for the power supply voltage to the oscillator as well as a bandpass filter to permit oscillator signals present on the loop to bypass open switch elements and be detected at any location in the loop. Frequency identifying means are coupled to the loop to permit an indication of which oscillators have been operated.

Abstract: An optical signal transmitter for use by priority vehicles for remotely controlling traffic signals, including a light source which is flashed at a controlled repetition rate to transmit an optical signal to a receiver located at the traffic intersection. Circuitry associated with the light source includes a comparator network for disabling an electrical energy supply in the event of certain predetermined operating conditions.

Abstract: A digital motor control system is provided to regulate the speed of a variable speed motor. Information concerning the speed and acceleration of the variable speed motor is used to generate a correction signal which causes the measured speed of the variable speed motor to approach the desired target speed.

Abstract: An electrically conductive web for safely and quickly discharging static electricity accumulated on personnel is disclosed. The web comprises a semi-conductive polymeric surface layer, which is in electrical contact with a conductive foraminous layer. The relative conductivity of these layers result in desirable electrical discharge characteristics. The composite structure may be bonded to a suitable supporting substrate and suitable electrical connection between the conductive foraminous layer is made with an electrical ground. Charged personnel coming into contact with the semi-conductive surface layer have their static charge quickly and safely discharged to ground potential.

Abstract: A high gain, front projection screen with controlled light distribution, comprising a translucent sheet containing light diffusing particles, having a matte-finished front surface and an incremental reflector rear surface.

Abstract: An apparatus for maintaining a history of instructions which have been most recently executed by a digital computer. A push-down stack is utilized for storing the contents of the program address counter, or the operand portion of the instruction register, of the computer upon the execution of every instruction and then pushing down the push-down stack whenever the last instruction executed by the digital computer was a branch type instruction. Provision may also be made for addressing the push-down stack so that the contents thereof may be reviewed in the order opposite from which it was loaded. This apparatus allows a user or diagnostic program to have access to the address of the most recently executed branch type instructions. In this way, a history of the most recently executed instructions can be maintained to aid hardware and software diagnostics.

Abstract: A method of addressing memory in a digital computer where a plurality of devices are connected to a single input/output channel to the digital computer communicate with the digital computer by externally specifying the memory address of the data word or words to be transferred to or from the digital computer. More specifically, the invention provides a method for treating the externally specified address coming from one of the multiple devices external to the digital computer as a virtual address. Thus, an input/output process operating in the digital computer may operate within the digital computer's system virtual address space. This method allows input/output processes to be able to utilize the address mapping subsystem of the central processor of the digital computer. The method of memory addressing utilizes a subchannel page table for each one of the multiple devices connected to one input/output channel in addition to a channel page table utilized for each individual input/output channel.

Abstract: The present invention relates to a memory addressing mechanism which has been formulated to accommodate three address structures: real, based and virtual. To accomplish this result the address generation function in the memory addressing mechanism has been separated into two distinct parts, address computation and address translation. By merely changing the hardware components in the address translation part of the memory addressing mechanism and leaving the hardware in the address computation part constant, an optional memory addressing mechanism which supports either a real address structure, a based address structure or a virtual address structure can be implemented.Further, the present invention with the virtual address translation apparatus in cooperation with the fixed address computation apparatus provides a virtual addressing mechanism which will compute and retrieve a memory word utilizing a four-segment memory address with only two memory references.