Abstract: A slidewire wiper contact has a wiper arm mounted at one end on a rotatable shaft while the other end of the arm carries an electrically conductive support extending past the end of the arm. A free end of the electrically conductive support has attached thereto a plurality of substantially constant outer diameter coils of electrically conductive wire. The coils are arranged in a continuous spiral while the electrically conductive support is attached thereto by a low resistance connection extending along a line on an outer surface of the coils. Electrical connection means are attached to the electrically conductive support for movement therewith during rotation of the wiper arm to maintain an electrical connection to the conductive support.

Abstract: A maximum frequency detector having a counter which counts through a certain number of counts unless an inhibit signal is received at a rate determined by the frequency of the clock pulse received. The inhibit signal is generated by a logic network to prevent the counter from producing an outgoing digital pulse of the digital pulse stream. The counter, the clock pulse generator and the logic network cooperate to have the frequencies of the incoming and outgoing digital pulses equal unless the incoming digital pulse stream has its frequency exceed the predetermined maximum frequency. In the event that the frequency of the incoming digital pulse stream exceeds the predetermined maximum frequency the frequency of the outgoing digital pulse stream is the certain predetermined maximum frequency.

Abstract: A preamplifier for a magnetic record reproducing system includes a differential amplifier construction wherein the input stage may be configured as a differential cascode arrangement for minimum noise at the lower frequency range or to be configured as an emitter-follower for maximum input impedance at the upper frequency range. The structure allows the amplifier to respond to very high frequencies, on the order of 4 MHz, without the introduction of an undesirable phase shift in the reproduced signal.

Abstract: A rotary valve has a fluid seal ring which is loosely captured within a valve body and provides a fluid seal at a peripheral edge of a movable member selectively positionable in a fluid conduit. The seal ring has an annular coaxial recess located on an inner side face thereof. A fixed valve seat member retained in the valve body coaxially with the seal ring has an outwardly projecting cantilever beam in the form of an integral annular ring located on a side face thereof. The end of the cantilever beam is provided with a tapered face arranged to cooperate with a tapered wall surface defining a side of the recess within the seal ring. The contact between the tapered side face of the cantilever beam and the tapered recess surface provides a fluid seal which is selectively positionable along the tapered recess surface to permit a self-aligning action of the seal ring to accommodate varying mechanical eccentricities of the seal ring in its fluid sealing position.

Abstract: An adapter converts a conventional thermostat to effectively approximate a setback thermostat. A conventional thermostat includes a mercury switch which is actuated by a bi-metallic coil. The attachment is interposed between the thermostat and its standard base plate and operates to tilt the entire thermostat under control of the timing mechanism to thereby effectively change the setpoint of the thermostat.

Abstract: A non-contacting apnea detector includes a long wave infrared detecting device which is arranged with a focusing means to define a predetermined field of view. This detector is positioned to include the infant or at least the head and shoulder portion of the infant in that field of view. The exhalations of the infant include large quantities of carbon dioxide. Carbon dioxide is absorbent to the long wave infrared radiation. The detector detects the difference in the infrared radiation due to the absorption incident to the exhalations of the infant. The resulting signal is applied to a suitable alarm circuit to indicate an interruption of the exhalation exceeding a predetermined time interval.

Abstract: A bidirectional tape reel brake has a spring loaded movable plate coaxially encircling a motor shaft and arranged to exert a braking force on the motor shaft in proportion to the spring pressure on the brake plate. A brake pad support plate is attached to an end of the motor shaft to position brake pads on the support plate between the movable plate and a fixed brake plate. A first spring is arranged to urge the movable plate toward the brake plate to clamp the brake pads therebetween. A plurality of supplementary or second springs are arranged to exert a supplementary braking force by providing additional spring pressure to the brake plate.

Abstract: A capacitive humidity transducer having an electrically non-conductive dielectric base carrying a pair of electrically conductive coatings deposited directly on opposite respective sides of the non-conductive base to form parallel capacitor plates. The conductive coatings are each arranged in a configuration of a plurality of side-by-side forked legs with the legs of the electrically conductive elements being positioned in a facing relationship. One end of each of the electrically conductive coatings is provided with electrical connectors for attaching the transducer to respective electrically conductive circuits which may be on a printed circuit board. The dielectric base is arranged to be hygroscopic whereby atmospheric humidity provides a corresponding variation in the dielectric constant of the base to affect the capacitance of the transducer.

Abstract: A butterfly valve having a valve body and a valve disc which is rotated to produce an engagement with a peripheral edge of the disc and an annular seat or wall defined by a portion of an internal fluid passage in the valve body uses a seal ring member mounted in an annular groove in the valve body adjacent to the annular seat. The seal ring member includes a pair of bowed seal rings arranged in a "V" within a triangular shaped annular recess in the wall of the fluid passage in the valve body. One side, i.e., an inner side, of each of the seal rings projects from the triangular recess to contact the edge of the valve disc to form a fluid-tight seal in response to fluid pressure acting on a convex face of a seal ring to flatten the seal ring. The other side of each of the seal rings contacts a respective corner of the recess with the convex faces of the seal rings facing each other.

Abstract: An ultrasonic signal transducer is characterized in that the piezoelectrically active element has a first unitary electrode over the entire surface of one face and a matrix of a plurality of individual electrodes on the opposite face. In the receive mode, such an arrangement effectively constitutes a plurality of individual transducers arranged in the matrix array while maintaining the efficacy of a unitary structure. The signals from the individual electrodes are individually amplified, full-wave rectified, and combined additively to produce a composite signal which eliminates the phase cancellation of the ultrasonic pulses distributed over the face of the transducer assembly.

Abstract: A multi-point recorder has a multi-color ink cartridge arranged to be selectively aligned with a recording head having a plurality of selectively energizable recording elements whereby a color from the multi-color ink cartridge is selected for printing by the recording elements. The recorder can either be operated in a fixed color operation by maintaining a preselected alignment of the recording head and a desired color in the multi-color ink cartridge or the color of the recording can be selectively altered at any time to produce a multi-color recording by selecting a corresponding color from the multi-color ink cartridge and aligning the recording head therewith for each recording. A drive mechanism having a single drive motor for the ink cartridge and the recording head is used to align the ink cartridge with the recording head along a recording line on a recording medium and to position the recording head and the ink cartridge at a printing location on the recording line.

Abstract: In an improved control circuit for the heating current of a system for developing latent photographic images on a heat developable medium, an incipient loss of tension in the record medium is sensed by detecting high frequency components of the energizing current incident to incipient arcing at the heating electrodes. The resulting signal is utilized to interrupt the flow of current to the heating electrodes, to prevent further arcing and the danger of fire. A time delay feature is incorporated to restore the heating current after a predetermined delay. If the tension in the record medium has not been restored, then the incipient arcing will again cause an interruption of the heating current.

Abstract: A shorting and test mechanism for an electrostatic air cleaner uses an electrically conductive spring element attached to an access door to the air cleaner whereby an opening movement of the door effects a motion of the spring to contact the high voltage electrode support assembly to discharge any residual electrical charge on the high voltage assembly to ground. Conversely, the closing of the access door forces the spring away from the high voltage electrode assembly to permit a normal operation of the air cleaner. The spring is further connected to an electrically insulating test button located in an opening in the access door to induce by an operator a selective motion of the spring toward the high voltage electrode assembly whereby to test for the existence of the high voltage on the electrode assembly by providing an electrical arc path to ground through the spring when the test button is depressed.

Abstract: A tape transport control system for monitoring the amount of tape on a tape reel using a first transducer means to provide a signal representative of the rotational speed of the tape reel. A fixed frequency oscillator is arranged to provide signals to be counted by a programmable variable modulo counter. The counter is programmed to start a countdown at a count preset by a digital word applied from a speed control selector for the tape transport. An output signal from the counter indicative of a fully decremented count status is applied to a two input AND gate which has as a second input signal an output signal from the reel transducer. An output signal from the AND gate is applied to the speed control selector to produce an interruption of an energizing signal to a capstan motor drive.

Abstract: A calorimetric apparatus for determining the calorific content of a fuel gas uses a reactor for producing oxidation of the fuel gas and a combustion gas in the presence of a catalytic oxidizer. The catalytic oxidizer is mounted on one end of a thermo-electric element which element has a heat absorbing end and a heat emitting end when energized by an electric current to produce a Peltier effect. The catalytic end of the element is mounted within the reactor while the other end is located outside of the reactor. The temperatures of the ends of the element are detected by a controller and the difference therebetween is maintained at a predetermined level during the catalytic reaction by the controller developing a control signal to control the supply of the electric current to the element. A display control signal is derived from the control signal by the controller and used to control a display for indicating the calorific content of the fuel gas.

Abstract: An adjustable overload mechanism for a differential fluid pressure transmitter includes a first and a second overload control diaphragm and an adjustable spring pressure means for applying an adjustable preload pressure to the control diaphragms. The spring pressure means for each diaphragm includes a spring such as a Belleville washer spring located between a diaphragm back-up plate in contact with a side of the control diaphragm and a wedge shaped support for the Belleville washer spring. A wedge shaped drive means is arranged to be selectively movable with respect to the wedge shaped spring support while maintaining the sloping wedge surfaces in contact. An adjustable drive screw is connected to the drive wedge to provide a means for changing the relative position of the support wedge and drive wedge.

Abstract: A calorimetric apparatus for determining the calorific content of a fuel gas uses a reactor for producing oxidation of the fuel gas and a combustion gas in the presence of a catalytic oxidizer. The oxidizer is heated by a constant current supply to a catalytic oxidation temperature. The resistance of the catalytic device is measured before and during the oxidation reaction which produces an additional heating of the catalytic device. The change in resistance is used to control a valve arranged to determine the flow rate of the fuel gas to the reactor. A display control signal is derived from a valve control signal and used to control a display for indicating the calorific content of the fuel gas.

Abstract: A unitary thick film resistor structure includes a first thick film resistor element formed on one face of a substrate and a second thick film resistor element formed on the opposite face of the substrate. The resistor elements are of complementary, substantially equal and opposite temperature coefficient of resistance characteristics such that when the two elements are connected in parallel to form a unitary structure, the opposite temperature coefficient characteristics provide a stable, mutually compensated low net temperature coefficient of resistance, and exhibiting an immunity to subsequent baking operations incident to the provision of a sintered protective outer coating.

Abstract: In a data protection apparatus for a multiple CPU system having a common or multiported bulk memory, an interface structure is associated with each of the CPU's. The interface structure cooperates with a firmware engine which is, in turn, a part of the interface control means which controls the transfer of data between the common bulk memory apparatus and each of the several CPU's in the system. Signals generated by the individual CPU's indicative of an emergency situation are applied as input signals to the interface structure. The interface structure then translates those signals into an attention flag signal and signals identifying the source or nature of the emergency. The firmware engine then responds to those signals and effects the necessary measures to protect the data relative to the affected CPU.

Abstract: A programmable digital memory circuit uses a programmable read only memory (PROM) to correct code errors and permit expansion to additional PROM chips. Each code correction or expansion is made via enabling a portion of an overlay patch programmable read only memory (PROM) for a similar portion of the memory circuit at an address code burned into the overlay trap (PROM). Initially the overlay trap PROM is unprogrammed, and each bit location therein can act as an enable/disable selection to a 32 byte block in the overlay patch PROM. When a bit in the overlay trap PROM is programmed and when the memory address selects that location, the main memory is unselected and the patch PROM location is selected, i.e., substituted. The 256 bit locations in the overlay trap PROM can select 256 32 byte patches in the patch PROM for substitution in the main memory.