Abstract: A solenoid valve includes a valve body (3), a ferromagnetic fluid flow damper (4) cooperating with a seat (6), to form a fluid sealing surface, an electromagnetic field coil (11) for selectively displacing the damper (4) against the action of a spring (7) by a magnetic field produced by an energization of the coil, an intake conduit (19) and an outlet conduit (20). The valve body (3) is housed in a cylindrical chamber (2) of a hydraulic unit (1) with an internal fluid intake pipe (14) and an internal fluid outlet pipe (22), communicating with their respective fluid intake (19) and outlet (20) conduits in the valve body (3). A flexible joint (16) connects the wall of the cylindrical chamber (2) with the rim of the intake conduit (19) and a compression spring (23) is located between the lower side (24) of the body (3) and the hydraulic unit (1) to provide an elastic suspension for the body (3).

Abstract: A method of digital temperature compensation uses a digital temperature compensation word to produce a digital word modification of a digital input to a temperature sensitive digital to analog converter hereinafter converter. The method includes the steps of sensing the temperature affecting the converter to produce a digital temperature representation which is used by a digital computer to produce an output in accordance with a characterization equation in the form of Output=f(D, M) where D=digital data and M=f(temperature). The temperature stability of the converter is affected by the temperature stability of a reference voltage circuit used in the converter and having a voltage reference diode. A compensation circuit uses a temperature sensor in the form of a second diode, which is thermally coupled to the reference diode, and a tracking type analog-to-digital converter for converting an analog signal.

Abstract: An electrical connector plug ejector apparatus includes a cogged belt having transverse teeth arranged to mesh with transverse surface grooves on an electrical connector plug. A snap-on cover is arranged to retain the belt to the surface of the plug with the teeth of the belt meshing with the plug grooves and the ends of the belt retained beneath the cover to form the belt into an endless loop above the connector. External electrical connections to the connector are provided by individual wires positioned in respective plug surface channels forming extensions of the grooves and arranged to exit beneath the edge of the cover. The belt provides a flexible handle for ejecting the plug from an associated socket while providing a strain relief for the electrical connections by transferring a retaining force for the belt supplied by the cover to the electrical connecting wires.

Abstract: An analog to digital converter uses an integrator having an input to which is applied the unknown voltage to be converted. An opposing reference voltage is switched by a switch means between positive and negative levels to cause the integrator output to ramp up and down between two levels to produce a periodic sawtooth waveform. The sawtooth waveform is applied to a hysteresis comparator which changes its output state when the sawtooth wave form magnitude equals the upper and lower hyteresis levels of the comparator. The output of the comparator is arranged to trigger an edge-sensitive "D" flip-flop. A fixed frequency clock signal from a clock signal source is applied to a clock input of the flip-flop to switch the flip-flop in combination with the output from the comparator. An output signal from one side of the flip-flop is applied as an actuating signal to the switch means to switch the reference signal level.

Abstract: A process controller with power outage analysis capability uses a real time clock generator powered by an uninterruptible power source for providing a real time reference which is used to measure the actual duration of a process controller disabling power outage. A non-volatile memory is also powered by the uninterruptible power source and is used to store the maximum allowable outage time limit for a particular process being controlled. The clock generator is initialized at the start of the power outage by a power outage detector which provides an early warning of an imminent power outage.

Abstract: An electrical connector for an oxidized surface includes a plurality of spaced apart parallel connector legs integrally formed as extensions of a central connector spine. Each connector leg has a free standing integral barb projecting therefrom toward an adjacent one of the connector legs. A group of legs is arranged to straddle a metal plate having an oxidized surface with the pointed ends of the barbs having a separation less than the thickness of the plate to enable the barbs to scrape the oxide from the surface to establish electrical contact to the underlying metal layer. The connector, in turn, is made of phosphor bronze to enable a spring-loaded electrical contact to be made to the connector surface by providing a low resistance non-oxidizing contacting surface.

Abstract: A three-way solenoid valve uses a movable armature housed in a coaxial sleeve and having longitudinal fluid channels on its outer surface and a fluid sealing element on both ends. A first fluid sealing element on a first end of the armature is a resilient ring arranged to cooperate with an adjacent fluid orifice in a valve body to peripherally seal the fluid orifice in response to spring pressure exerted by a spring acting on the first end of the armature in a first position of the armature during an deenergized state of the valve. The armature is provided with a coaxial longitudinal bore aligned with the center hole in the fluid sealing ring. During the deenergized state of the valve, a fluid path is provided between a first fluid port and second fluid port in the valve body via the hole in the sealing ring, the bore in the armature and the channels on the armature.

Abstract: An ionization detector for detecting a vapor constituent uses a first mode of operation in which only the vapor carried by ambient air is conducted through the ionization detector and a second mode of operation in which the outlet line from the ionization detector is connected to direct the exhaust gas flow from the ionization detector through a desiccant cartridge to remove humidity from the gas flow exiting from the ionization detector. The dehumidified gas with the constituent to be detected is then reintroduced into the input of the ionization detector to provide an improved sensitivity of the detector to the constituent. An alternate first and second operating mode cycle is provided to produce an increased output level of constituent detection from the ionization detector. This increased output level can be arranged to initiate an alarm operation for the vapor constituent being detected even at a very low constituent concentration.

Abstract: An electrode system for an electrochemical sensor has a plurality of electrically conductive sensing segments isolated from each other and mounted on a support substrate formed from a chemically inert encapsulation material. The sensing segments are unencapsulated and are each coated with respective ones of ion conducting sensing materials to characterize each of the segments except for one of the segments which is uncoated and is arranged to be used as a reference electrode. The outer surface area of the sensing materials and the reference electrode is coated with a layer of a nonaqueous electrolyte which serves as a sorption/desorption medium. The electrolyte, in turn, is covered by a semipermeable thin film membrane secured at its peripheral edge by an O-ring to the support to form a fluid seal. Electrically conductive leads are connected to respective ones of the sensing surfaces, and a temperature measuring device is provided in the electrode structure for temperature compensation.

Abstract: A sensor communication system uses a shared analog signal to duty cycle converter for producing a comparison between a predetermined free-running triangular waveshape and a selected output signal from a plurality of analog signal sources such as process sensors, to convert the amplitude of the analog signal to a variable duty cycle signal. The variable duty cycle signal is subsequently converted to a digital signal which may be represented by a count stored in a counter counting clock pulses during the occurrence of the pulse width waveshape of the variable duty cycle signal. The digital signal is utilized as a digital word by a microprocessor operating in accordance with a stored program to produce a characterized digital output signal for use in a communication after conversion to a 4-20 ma control signal for communication and control in an industrial process control system.

Abstract: A flow sensor having adjustable sensitivity includes a differential pressure sensing element located in an internal compartment within a rotatable cylinder. The compartment is connected between diametrically opposite fluid ports on the surface of the cylinder by fluid channels. In one embodiment, the sensor is located on a diaphragm partitioning the compartment into a first and a second chamber with the sensor being responsive to a distortion of the diaphragm induced by a differential pressure. In a second embodiment, the sensor is a flow sensor and is arranged to monitor a fluid flow through the compartment induced by a differential pressure. The cylinder is rotatable on an axis at located right angles to a fluid flow thereacross whereby the ports are selectively located at a desired angle with respect to the fluid flow path. The cylinder is located within a fluid-tight housing having a fluid inlet and a fluid outlet arranged to direct a fluid being monitored by the sensor around the cylinder.

Abstract: A variable gain amplifier is adjusted to maintain its amplification within a linear range, i.e., to prevent saturation of the amplifier, by utilizing the output of an analog-to-digital converter, which is arranged to convert an analog output of the amplifier to a digital representation, by a digital computer to effect the gain change of the amplifier. Concurrently, the output signal of the digital computer representing the output signal from the analog-to-digital converter is modified to produce a system output signal based on a constant overall gain of the system which is equivalent to the highest available gain from the amplifier. Thus, while the amplifier gain is adjusted by the computer in response to the amplitude of the input signal, the overall system gain is maintained at a level which would be available at the highest amplifier gain. The digital output of the system can subsequently be utilized as a control signal either directly or after a digital-to-analog conversion.

Abstract: The method for spacing the folds of a folded filter media assembly includes the steps of separating the folds of the filter media by the use of the tapered assembly comb having uniformly spaced teeth and subsequently inserting a rigid divider into the separated and spaced media folds to produce a uniformly spaced filter media. The comb can be discarded after the divider is inserted, and, accordingly, the comb is made of an inexpensive material having a desired degree of rigidity for handling, e.g., cardboard. The uniformly spaced filter media assembly is inserted into an operative position for filtering, e.g., as an air filter.

Abstract: A two-stage solenoid valve uses a pair of stacked coaxial armatures separated by a predetermined gap which is maintained by a first spring therebetween. A coaxial connecting rod extends between a first armature and the second armature and is attached to the first armature. A head on the unattached end of the rod bears against a bottom surface of a recess in the second armature to limit the expansion of the first spring. A second spring is arranged to contact the head of the rod and to extend therefrom to a fixed plug in the end of a cylindrical housing surrounding the first and second armatures. The first armature is provided with a fluid sealing surface on a first end for sealing an adjacent fluid port in the valve in response to the spring force exerted by the second spring. A first and a second solenoid coil assembly are coaxially stacked to surround the cylindrical sleeve housing adjacent to respective ones of the first and second armatures.

Abstract: An electromagnetic relay having a dual acting armature has a U-shaped armature with two divergent legs. The armature is pivoted on one of the legs with the pivoted leg being arranged adjacent to an electromagnetic field producing structure including an electrically energizable coil. A first movable electrical contact carrying means is arranged to cooperate with a first one of the legs of the armature to produce a motion of a first electrical contact between a first and a second position in response to an energized and a non-energized state of the coil, respectively. Concurrently, a second movable electrical contact carrying means is arranged to cooperate with the other or second leg of the armature to produce a motion of a second electrical contact between a first and a second position in response to an energized and deenergized state of the coil, respectively. The coil is located in the bight of the U-shaped armature with the pivoted first leg being urged by a spring away from the coil.

Abstract: A method of producing a fluid-tight seal between a thin, flexible member and a support including the steps of providing a moat for receiving excess braze material on an external surface of a member support and a dam adjacent to the moat to confine the excess braze material to the moat and having a height above the bottom of the moat to accommodate a brazing of the member to the external surface, positioning the member to extend across the dam and the surface while contacting only the top of the dam and brazing the member to the surface while maintaining the contact between the top of the dam and the member to uniformly support the member.

Abstract: A data distribution apparatus for controlling the distribution of data signals from field mounted devices to a central processor includes a backplate having wiring connected thereto between the backplate and the field mounted devices and between the backplate and the data processor. A cover for the backplate includes a printed circuit board mounted thereon with an electrical connector extending therefrom. The cover connector is arranged to mate with an electrical connector board mounted on the backplate to selectively connect the printed circuit board on the cover to electrical circuits connected to the connector board on the backplate. Thus, the removal of the cover which is keyed to the backplate to ensure a correct orientation thereof on the backplate is effective to interrupt the electrical connections provided by the printed circuit board among the wiring connected to the electrical connector board and vice versa.

Abstract: A pneumatic valve uses a body made of a synthetic material with a plurality of internal fluid ducts opening onto a face of the body via respective orifices. A metal plate is arranged in contact with the aforesaid face and is provided with sockets aligned with respective ones of the duct orifices and each containing a tapped hole capable of receiving a threaded connecting pipe. Resilient O-rings are used to provide a fluid-tight seal between the sockets and the ducts.

Abstract: A solenoid valve includes a body (2,25) with an internal intake pipe (26) and an internal outlet pipe (27), a coil (4) and a movable stem (3), urged by a spring (10) toward a valve closed position. The stem (3) defines, with a seat (30), an annular sealing surface (22), surrounded by a groove (17) and by an annular flange (18). The flange defines with an annular counterpart (25) placed opposite, an annular damping surface (23). The groove (17) communicates with the outlet pipe (27) through a longitudinal slot (12) provided in the stem (3). The annular flange (18) is in a position near or in contact with the counterpart (25) when the valve is closed. During a closing of the valve, the liquid between the annular flange (18) and the counterpart (25) escapes radially through the groove (17) from the annular damping surface. This produces a braking effect on the stem (3), to reduce wear on the annular sealing surface (22).

Abstract: A method of measuring the specific gravity of a fluid to be analyzed includes the steps of pressurizing a fixed volume chamber by the fluid to be analyzed, allowing the pressure in the chamber to decay through a fixed restriction between predetermined pressure limits, measuring the time interval of the pressure decay between the pressure limits and converting the time interval value to the specific gravity of the fluid to be analyzed.