Abstract: An apparatus for controlling and monitoring actuators with an open/close characteristic consists of a first unit having a drive switch unit for operating a drive force unit, at least one limit signal generator that detects an end position of an actuator of the drive force unit and an electronic unit, such as a microprocessor, which first unit is connected to a second unit by a twin-core cable, and the second unit includes an apparatus for operating the drive switch unit and for outputting the state of the limit signal generator.

Abstract: A liquid level controller is shown having a housing with a rear wall. A shaft has a first end which extends through the rear wall to a liquid displacement member located within a liquid containing vessel. A second end of the shaft joins a pair of oppositely extending arms. Each of the oppositely extending arms is rotationally mounted on the housing generally parallel to the rear wall in a bearing. Vertical forces responsive to changes in liquid level act on the displacement member and are transmitted as a force tending to rotate the oppositely extending arms. A lever pivotally mounted to the housing is interconnected with a torque bar which, in turn, connects to the oppositely extending arms of the shaft. A valving assembly is engaged by the lever to provide an output for controlling liquid level within the vessel. The valve assembly includes a pneumatic pilot with a contact point which is engageable by a pin carried on the lever.

Abstract: When a steplike reference signal is supplied while a switch is open, an offset signal for compensating for the dead time of a pneumatic device is generated by an offset generator and supplied as a manipulated variable for the pneumatic device. When a feedback increases in level and a speed higher than a reference speed is detected by a speed detector, the switch is closed by a switching signal, switching from a PD control mode to a PID control mode. The pneumatic device thus controlled has a reduced response time and can made a quick response.

Abstract: The present invention includes an electropneumatic positioner having an external binary input block which provides access to the electrical output of an integral electronic position controller to control operation of a valve relay. The invention enables manual control of the positioner for safety, maintenance etc.

Abstract: A liquid level controller is shown having a housing with a rear wall. A shaft has a first end which extends through the rear wall to a liquid displacement member located within a liquid containing vessel. A second end of the shaft joins a pair of oppositely extending arms. Each of the oppositely extending arms is rotationally mounted on the housing generally parallel to the rear wall in a bearing. Vertical forces responsive to changes in liquid level act on the displacement member and are transmitted as a force tending to rotate the oppositely extending arms. A lever pivotally mounted to the housing is interconnected with a torque bar which, in turn, connects to the oppositely extending arms of the shaft. A valving assembly is engaged by the lever to provide an output for controlling liquid level within the vessel. The valve assembly includes a pneumatic pilot with a contact point which is engageable by a pin carried on the lever.

Abstract: A first pressure chamber and a second pressure chamber are provided with means for continuously exerting a constant inward pressure on a first diaphragm part and a third diaphragm part respectively. A valve chamber having a flow control portion wherein a flow rate of the controlled fluid flowing from an inflow chamber to an outflow chamber is controlled by changing a size of the opening defined between a valve part and a valve seat, caused by a displacement of the valve part of a valve mechanism. A differential pressure chamber connects with the outflow chamber and has a bypass opening of a bypass passage connecting to the outflow passage.

Abstract: A feedback control system (i.e., a positioner) for precise positioning of a pneumatic actuator by adjusting the flow of air to the pneumatic actuator comprises an adjustable gain mechanism for adjusting the sensitivity of the positioner. The adjustable gain mechanism is coupled between a feedback input device of the positioner and a valve control device and is employed to adjust the amount of air supplied to the pneumatic actuator for a given displacement of the feedback input device. Preferably the adjustable gain mechanism is adjustable through a range of settings between a high gain setting and a low gain setting, the high gain setting allowing a greater range of motion of the valve control device than the low gain setting for a given displacement of the feedback input device.

Abstract: An electropneumatic positioner includes a data processing control section and an electropneumatic converter. The control section includes first and second position determining sections and a signal setting section. The first position determining section obtains the valve opening degree positions of a regulating valve as the minimum and maximum valve opening degree positions which are set when a driving signal for conversion from an electrical signal into an air pressure is set to the minimum signal and the maximum signal. The second position determining section obtains the valve opening degree position of the valve which is set when the driving signal is the minimum signal on the basis of the relative positional relationship between the obtained minimum and maximum valve opening degree positions and the valve plug form of the valve.

Abstract: The electronic instrument has a two-part housing (26, 27) which surrounds in a dusttight manner a printed board fitted with at least one electronic component. The housing (26, 27) contains a ventilating orifice (50) led through one of its two parts. A ventilating device (51) is arranged in this ventilating orifice (50), with an air-permeable diaphragm permeable to water vapor in a directionally dependent manner and with a splashwater guard preceding the diaphragm.Undesirable condensation water in the housing interior is avoided, since excess water vapor present in the housing interior is led outward through the diaphragm while the electronics are operating. At the same time, the splashwater guard prevents the diaphragm from coming into contact with splashwater and its operating capacity from being impaired.

Abstract: An electrical-pneumatic system has a controller which has an input terminal for a reference variable signal, an input terminal for a regulating variable or feedback signal and an output terminal for a manipulated variable signal, which preferably is a pulse-width modulated signal. The controller will actuate a drive unit of an electrical-pneumatic pre-control unit, which has a 3/2 directional control valve that responds to the pulse-width modulated signal from the controller. The output of the 3/2 directional control valve is smoothed by being passed through a throttle and into a volume, and a pneumatic booster is connected downstream from the volume. The output of the pneumatic booster is sensed and provides the feedback signal.

Abstract: A pressure control valve, which possesses a primary pressure port, a secondary pressure port and a venting port. For control of the secondary pressure a valve operating device is present which is actuated by a control pressure present in a control chamber. A mechanical spring device urges the valve operating device against the direction of action of the control pressure in such a manner that when ambient pressure obtains in the control chamber, it automatically assumes a basic setting, in which the secondary pressure port is connected with the venting port for fluid flow. It is in this manner that there is an automatic venting of the secondary pressure port when the control chamber is free of pressure.

Abstract: An electropneumatic positioner includes an electropneumatic converter, an pilot relay, an operating unit, and a sensor. The electropneumatic converter includes a yoke having central and side leg portions, a permanent magnet arranged on the central leg portion, a pair of coils for exciting the side leg portions to have opposite polarities, a nozzle embedded in one side leg portion to spray air having predetermined pressure, a stopper arranged on the other side leg portion, and a flapper arranged to be swingable on a fulcrum near the central leg portion and serving to change a nozzle back pressure by controlling the amount of air sprayed from the nozzle in accordance with a swing. The electropneumatic converter receives a duty signal, as a driving signal for the coils, which signal is obtained by converting a deviation between an input signal and a feedback signal into a duty. The flapper is set to be parallel to the yoke when the deviation between the input signal and the feedback signal is zero.

Abstract: An electropneumatic converter controlled by solenoid valves, in which the solenoid valves are connected respectively to the feed pressure and to atmosphere, each via a pressure regulator controlled by a differential pressure measurement device connected across a respective solenoid valve, so as to maintain a constant pressure difference across the solenoid valves.

Abstract: A device capable of comparing the travel position of an output shaft of a diaphragm actuator or cylinder with the current level of an electronic input signal and further being capable of manipulating the pressure of a separate air signal piped to a diaphragm actuator or cylinder in order to correct any imbalance between such a shaft position and a given electronic signal level, including the ability of varying its dynamic response through built in adjustments.

Abstract: A control system for a pneumatic valve actuator comprising three operating blocks memorizing respectively the values of the spring pressure p.sub.m, the counter-thrust pressure p.sub.c and the friction pressure p.sub.a for the various valving member position values, said blocks being connected in parallel and, via a switch, to the valving member position transducer or to the set position generator and connected to the pressure computing block connected via a second switch to the pressure generator or, together with the value read by a transducer for the pressure existing in the actuator, to a differentiator connected to two multiplier units for K and for (1-K) respectively, which are connected to the transit memory of the p.sub.c operating block and to the p.sub.a operating block respectively, the switches being driven by a logic control unit which switches over when the valving member is at rest. Means are provided for sensing anomalies and the extent of wear.

Abstract: An electro-pneumatic converter device with modular components and with supporting housing structure enabling the device to be readily convertible from a current to pressure positioner to a current to pressure transducer. A valve positioner with an enclosure having a housing, a modular base, and a separable field terminal box. A self contained cover mounted to the enclosure with no additional mounting components. A plastic pneumatic relay ultrasonically welded together to eliminate metal mounting parts and lower assembly time. Open channels in a housing surface cooperating with a gasket to provide fluid passageways between the housing and the modular base. Pressure gauges are removably mounted on a modular unit for location completely within the housing. A floating interconnect terminal board permits self-aligning of mating terminals as the modular unit is inserted into the housing.

Abstract: A pilot signal control assembly (10) controls the pilot signal of a valve (18) which is connected to regulator, typically a booster regulator (12). The valve (18) receives air from an air supply (14) and, pursuant to an error signal (E(t)) , defined as the command signal (C(t)) less a modified feedback signal (F(t)) , modifies its output, the pilot pressure signal. The booster regulator (12) receives the pilot pressure signal and modifies its output (P.sub.o (t)) accordingly. A feedback loop (24) transforms the output pressure (P.sub.o (t)) into a voltage signal. The voltage signal is multiplied by a proportional factor (A) based on the size of the booster regulator (12). In a signal subloop (30) of the feedback loop (24), the first derivative is taken of the voltage signal. The multiplied signal and the first derivative are added to create the feedback signal (F(t)) which is eventually subtracted from the command signal (C(t)) to create the error signal (E(t)).

Abstract: A valve assembly controls a pressure sent from a valve to create a pilot signal used to control a mechanical booster regulator. An independent feedback line extends from both the output of the valve and the output of the mechanical booster regulator wherein the outputs are scaled after a transducer in each feedback line converts the information received from the pressures into voltages. The difference in the voltage is integrated and added to the input command signal which dictates the parameters of the mechanical booster regulator operation. The voltage feedback from the pilot pressure is then subtracted from the modified command signal. The feedback signals approach a negligible correction as the mechanical booster regulator approaches the designed output pressure because the integration is eliminated and the pressures cancel each other as the system approaches a static condition.

Abstract: Problems such as slow frequency response and low reliability when operating with contaminated fluids of variable viscosity are alleviated in a low pressure hydraulic system (10) which utilizes a single stage, electro-hydraulic, clevis-type pressure control valve (40). The valve (40)includes a control piston (106) referenced to a control pressure within a control pressure cavity (60) to provide a feedback of control pressure which converts the valve (40) from an integral to a proportional control device, thereby enhancing stability of the hydraulic system (10). Compensation for changes in fluid viscosity, as a result of changes in fluid temperature, is provided by fabricating a bifurcated portion (98) and/or a metering bridge portion (62) of the valve (10) from materials having dissimilar coefficients of thermal expansion.

Abstract: An electro-pneumatic control system and single op-amp PID control circuit is provided for regulating the output pressure response provided to a load. The control system includes a control valve for producing a control pressure signal and a booster for providing an output pressure response to a pneumatic load in accordance with the control pressure signal. A pressure sensor is further provided for measuring the output pressure response provided to the load and for generating a corresponding feedback voltage signal provided to the control circuit. The control circuit compares the feedback signal to a command signal input in accordance with a predetermined transfer function having proportional, integral and derivative (PID) components, and generates a control voltage signal for stably controlling the output pressure response provided to the load.

Abstract: An electric to pneumatic transducer including a transducer housing with a primary converting housing section and a relay housing section. The primary converting housing section contains feedback and control electronics and an electronic feedback sensor that are electrically connected. The feedback and control electronics are adapted to be connected to an electronic signal input. The primary converting housing section also contains a nozzle and associated flapper control for controlling the output from the nozzle and the primary converting housing section also contains a bleed orifice. The relay housing section contains a relay control chamber with a positive bias spring that exerts a force on an upper control diaphragm and an associated lower control diaphragm that are in turn associated with a combined exhaust and supply valve.

Abstract: An electro-pneumatic converter device with modular components and with supporting housing structure enabling the device to be readily convertible from a current to pressure positioner to a current to pressure transducer. A valve positioner with an enclosure having a housing, a modular base, and a separable field terminal box. A self contained cover mounted to the enclosure with no additional mounting components. A plastic pneumatic relay ultrasonically welded together to eliminate metal mounting parts and lower assembly time. Open channels in a housing surface cooperating with a gasket to provide fluid passageways between the housing and the modular base. Pressure gauges are removably mounted on a modular unit for location completely within the housing. A floating interconnect terminal board permits self-aligning of mating terminals as the modular unit is inserted into the housing.

Abstract: A valve positioner controls operation of a valve in a process control system. The valve positioner is coupled to a process control loop over which it receives a signal representative of a desired valve position and operating power for the positioner. The valve positioner controls a pneumatic actuator which in turn controls position of the valve. The valve positioner includes a microprocessor, associated digital circuitry and analog circuitry. Low power analog circuitry performs PID control functions. The microprocessor periodically updates at least one digital control signal used to selectively program a resistance in the analog circuitry. The combination of digital and analog circuitry allows reduced power consumption because the analog PID function consumes less power and is performed more quickly than the microprocess could perform the same function.

Abstract: A hyper-reset pressure controller which includes two separate feedback paths which results in a substantially smoother and more accurate pressure control.

Abstract: A fail-safe, precision current-to-pressure converter for providing a regulated pneumatic output pressure proportional to an electrical control current includes a main valve member for regulating the pneumatic output pressure, operation of the valve member being controlled by the pressure of control fluid contained in a chamber. The control fluid pressure is controlled by admitting control fluid into the chamber via a continuously pulsed, electromagnetically actuated on/off reed valve and simultaneously allowing control fluid continuously to exhaust to atmosphere via a fixed bleed orifice, the rate of admittance of control fluid into the chamber relative to the exhaust rate from the orifice being variable so that the desired, substantially constant output pressure, as dictated by the electrical current input and as measured by a transducer that produces a feed-back signal, will be attained.

Abstract: A pneumatic controller configured to regulate the opening and closing of a controlled device in response to a measured variable, such as temperature. The pneumatic controller includes a sensor providing an output proportional to the measured variable as well as a gas supply inlet and a gas outlet. A pneumatic relay is disposed between the inlet and the outlet for regulating the pressure of gas passing through the inlet to the outlet to the controlled device. A pneumatic actuator system is connected to the relay and regulates the relay via cooperation between an inflatable bladder and a pneumatic pilot circuit in the relay. The pneumatic actuator system includes a first electric microvalve which selectively permits passage of a gas into the inflatable bladder and a second electric microvalve which selectively permits passage of a gas out of the inflatable bladder in response to a digital controller connected to the sensor.

Abstract: A device for converting an electric current signal into a mechanical correcting variable, includes a pneumatic correcting element (1) with slide rod (2), a pneumatic amplifier (3), a compressed-air supply (4) and an electropneumatic signal converter which has a solenoid (5) with coil, iron circuit and air gap, a nozzle/baffle-plate device (6), and a lever (8) which is swingably mounted on a tensioning band (7). One end of the tensioning band (7) is mounted for turning around its longitudinal axis and, perpendicular to the longitudinal axis there is arranged a feedback lever (12) one end of which is attached, fixed in rotation, to the turnable end of the fastening belt (7) while its free end is coupled to the slide rod (2) of the pneumatic correcting element (1).

Abstract: A pressure modulator includes an electromagnetic coil wire wound about a hollow axle for developing a magnetic field when electrical current is applied to the wire, the hollow of the axle having an entrance port for receiving a fluid and a discharge port for discharging the fluid. The modulator serves to control the pressure of fluid flowing through a conduit under pressure and further includes a bleed-off tap connecting the conduit to the entrance port. A diaphragm plate is disposed above the coil of wire and axle and adjacent to the discharge port of the hollow to modulate the rate of fluid flow from the discharge port. The diaphragm plate includes a central void, a central section of magnetically attractable material disposed in the void above the coil of wire for attraction toward the coil when electrical current is applied to the coil to thereby limit the amount of fluid which is allowed to escape from the discharge port.

Abstract: An electro-pneumatic pressure transducer is provided with a valve body assembly having a supply chamber, an exhaust chamber and an intake assembly to provide a source of fluid to the transducer. The transducer also has an output assembly directing the fluid to a pneumatic actuator. The valve body further includes a supply valve assembly and an exhaust valve assembly having bender elements adjustably mounted to the valve body with respect to nozzles. A manifold structure is included for fluidly connecting the supply valve, the exhaust valve and the output assemblies. A pressure sensor is used to measure the pressure in the valve body and is responsive to increases or decreases of the pneumatic pressure in the valve body. A monitor is used to monitor the power source and to generate a failure mode signal when the power source fails to supply a predetermined level of power.

Abstract: Liquid level control apparatus consisting of a valve frame with supply gas throughput through an adjustable orifice post and a float actuated release of orifice post pressure to cause a sharp change in pressure to actuate a pressure-responsive dump valve. Proposed then is the further interconnection of the valve frame in reversed disposition to a snap action pilot valve thereby to provide a non-bleeding mode of valve control.

Abstract: A motion balanced pneumatic pressure controller comprised of a tubular housing having a diaphragm for sensing a process pressure on one side and a second diaphragm for sensing a pneumatic output signal on the other side; both diaphragms are connected by a stem passing the length of said housing and having valving means attached to open or close a bleed port within the second diaphragm to modulate a pneumatic signal pressure derived from compressed air passing a primary adjustable restriction in direct proportion to the movements of the first diaphragm, such movements being the results of process fluid pressure changes on the first diaphragm being supported by the force of adjustable springs.

Abstract: A mechanical flexure element useful for motion amplification with a closed end and two legs extending therefrom in a general U-shaped configuration. One leg may be fixed and the other leg moved, or both legs may be movable with respect to each other. Microdisplacements of a leg are amplified and translated into larger transverse movements of the closed end. Reversing the input and output displacements provides attenuation of a larger input displacement. A magnetostrictive electromechanical transducer with a flexure element having a closed end and two legs extending therefrom moving towards and away from a nozzle in an enclosed nozzle chamber under fluid pressure. An electrical input signal actuates a magnetostrictive element coupled to one leg of the flexure element to move the element with respect to the nozzle thereby changing the fluid output pressure from the nozzle chamber.

Abstract: An electrohydraulic servovalve comprising a torque motor which receives an electrical signal and positions a flapper between a pair of opposed nozzles to control a spool valve and a feedback spring connected to the flapper and to the spool of the spool valve. The flapper is connected to an armature of the torque motor. The joint between the armature and the flapper comprises a one part, heat cured thermosetting adhesive.

Abstract: An electro-pneumatic transducer converts an electrical input signal into a proportional (direct or indirect) pneumatic output signal. A circuit will sense the magnitude of the input signal, monitor the output fluid pressure and adjust a piezoelectric beam voltage until a desired output fluid pressure is achieved. The output fluid pressure is controlled by the deflection of a piezoelectric beam which is polarized and will deflect with an applied voltage. The output fluid pressure is monitored by a pressure sensor.

Abstract: An electrohydraulic servovalve comprising a torque motor which receives an electrical signal and position a flapper of a spring tube and flapper subassembly between a pair of opposed nozzles to control a spool valve and includes a feedback spring connected to the flapper and to the spool of the spool valve.

Abstract: A four-mode pneumatic relay includes a relay body defining four chambers, each coupled to a port. Two of the chambers are formed by a diaphragm assembly consisting of a rolling diaphragm coupled to an input post that drives a movable orifice shaft and a pair of diaphragms of different effective areas coupled to said movable orifice shaft. A movable plug assembly includes valve plugs for interconnecting the first chamber with the second chamber and the second chamber with the third chamber via a valve seat and an orifice and recess in the movable orifice shaft. A pair of mechanical switches couple different ones of said ports for providing multi-mode operation. One switch supplies input pressure to either the first port or the third port and another switch couples the second and fourth ports together to vents the fourth port.

Abstract: A solenoid valve is provided which is so constructed that reaction chambers are formed on both sides of a spool. Into the reaction chambers is introduced the loading pressure of an actuator to accomplish the balance between the pressing force of proportional solenoids and the reaction force of the reaction chambers, resulting in a control pressure applied to a cylinder being automatically adjusted depending on the loading pressure of the actuator.

Abstract: A railway car pressure control valve having an adjustable middle body member. An air supply chamber connected to a source of compressed air and an output chamber connected to an output passage. An exhaust chamber opened to the atmosphere. An air supply valve spring biased toward a valve seat. A hollow exhaust valve rod having a valve tip located adjacent the air supply valve. A control piston including a control piston diaphragm is attached to the inside wall of the main valve body. A balance piston including a balance piston diaphragm attached to the inside wall of the main valve body. A plurality of first and second radially extending fins carried by the balance piston and the inside wall of the main valve body, respectively. A protective member interposed between the balance piston diaphragm and the radially extending fins to prevent wave distortion of the balance piston diaphragm and preclude increase resistance to movement of the main piston.

Abstract: A solenoid operated fluid pressure regulating valve includes a valve responsive to outlet pressure to control the rate of fluid flow to a burner. The valve is biased to a first position to effect a low fire fluid flow rate and to a second position to effect a high fire fluid flow rate. The first and second positions are independently adjustable so as to enable independent field adjustment of the low and high fire fluid flow rates. Lower and upper limits to such field adjustments are established in the assembly of the valve.

Abstract: A pneumatic control valve comprises a position controller and a valve which is influenced by the controller. A valve member can be lifted by means of a servomotor which is securely connected to the valve housing by means of a yoke, the servomotor being connected to the valve member by means of a valve rod. The lift position of the valve rod is sensed by means of a rotatable lever of the position controller, which rotatable lever is in a working connection with the valve rod by means of an articulated device. A housing encloses the valve rod, the lever and the articulated device.

Abstract: A pneumatic control valve comprises a position controller and a valve which is influenced by the controller. A valve member can be lifted by means of a servomotor which is securely connected to the valve housing by means of a yoke, the servomotor being connected to the valve member by means of a valve rod. The lift position of the valve rod is sensed by means of a rotatable lever of the position controller, which rotatable lever is in a working connection with the valve rod by means of an articulated device. A housing encloses the valve rod, the lever and the articulated device.

Abstract: A load dependent valve for railway cars including first and second springs, each having one end contacting a balance piston. A first spring adjusting mechanism for adjusting the compressive force of the first spring and a second spring adjusting mechanism for adjusting the compressive force of the second spring. A valve seat disposed in an air supply passage which is connected between an air supply chamber and an output chamber. An air supply valve is biased to seat on the valve seat. An exhaust valve rod having a valve tip facing the air supply valve and fitting the air supply passage and has an exhaust air bore, one end opens at the valve tip and the other end opens at the exhaust chamber. The control piston including a control piston diaphragm fixed to the main valve body and fixed to the control piston. The balance piston includes a balance piston diaphragm which is fixed to the main valve body and also is fixed to the balance piston main body.

Abstract: An electropneumatic transducer for converting an electric signal to a pneumatic pressure has a nozzle flapper mechanism and a pilot valve engaging a diaphragm assembly. The nozzle flapper mechanism has a nozzle flapper composed of an electrostrictive element. The diaphragm assembly comprises two diaphragms having different effective areas. A nozzle back pressure is applied to one of the diaphragms, and an atmospheric pressure is applied to the other diaphragm. A supplied pressure or output pressure is applied between the two diaphragms. The nozzle back pressure is varied dependent on the voltage applied to the electrostrictive element for moving the diaphragms to enable the pilot valve to control a valve disposed in a passage connecting supply and output ports.

Abstract: A pressure control valve for railway vehicles having a variable control mechanism for adjusting the gain of the output pressure to input pressure by controlling the effective area ratio on opposite sides of a piston. A balance diaphragm disposed on one side of the piston and a control diaphragm disposed on the other side of the piston. A plurality of first radial fins carried by the piston and a plurality of second radial fins carried by the body of the control valve. The ends of the first fins are placed between the ends of the second fins so that the edges form a slant surface. Thus, at least one of the diaphragms is supported by the slanted surface of the first and second fins. A manual adjusting mechanism for varying the position of the piston of the valve for changing the ratio of the effective areas.

Abstract: A flapper actuated pilot valve is shown is which the output pressure from the valve is dependent upon and proportional to the force exerted by the flapper. The valve includes a valve body with upper and lower chambers and an interconnecting gas passage. A spring-biased poppet in the lower chamber has a primary sealing surface for sealing off the lower chamber and a secondary sealing surface which is contacted by a flapper element located in the upper chamber. The flapper element has an interior bore leading to an exhaust port in the upper end of the flapper element which extends through an opening in the valve body. The flapper element also extends through a central opening provided in a cupped seal in the upper chamber. The cupped seal and primary and secondary sealing areas of the flapper element cooperate to provide and outlet gas pressure which is proportional to the external force supplied by the flapper upon the flapper element.

Abstract: A current-to-pressure transducer that is insensitive to shock employs a magnetic fluid that deforms a flexible diaphragm in response to an electrical input current that is applied to a coil and magnetic circuit. The deformed diaphragm varies the air space between the diaphragm and a nozzle connected to the air line so that the pressure within the air line is effectively controlled.

Abstract: An electropneumatic position regulator having a current/pressure transducer has, as electric input, at least one coil (11) fed with a current (setting signal), as well as a permanent magnet (16) whose relative position is variable as a function of the current for the adjustment of a nozzle/impact-plate arrangement (17, 18) of a pneumatic system. The position regulator serves for a pneumatic setting device (23) which has a stroke output and is connected with the nozzle/impact-plate arrangement. The position regulator furthermore comprises a position report device with an electric path transmitter (31) which is connected to the stroke output (32) of the setting device (23). The report signal from the electric path transmitter (31) is fed back to the electric input (coil 12) of the current/pressure transducer.

Abstract: The incremental interface system of the present invention includes a pneumatic input means for providing a first pressure to be regulated. A pressure repeater means includes a volume relay having a first chamber coupled to the intermediate bus of the input means and a second chamber coupled to a pneumatic transducer to be controlled, the first chamber and the second chamber being in fluid flow isolation one from the other. The pressure repeater means provides a second pressure at its second chamber which has a predetermined relationship to the first pressure. A reservoir means is coupled to the intermediate bus between the input means and the repeater means for limiting the rate of change of the first pressure. The input means, repeater means and reservoir means cooperate to define a substantially constant volume of fluid.

Abstract: The interface apparatus of the present invention includes a pneumatic flow control means for controlling the number of moles of a gas confined within a substantially constant volume of gas at a first pressure. A volume relay has a first chamber coupled to the control means by a pneumatic bus and a second chamber for coupling to a pneumatic transducer to be positionably controlled, the first chamber and the second chamber being in fluid flow isolation one from the other. The volume relay provides a second pressure at its second chamber which has a predetermined relationship to the first pressure. A substantially constant, confined volume is coupled to the flow control means and to the relay and the flow control means includes means for adjusting the rate of flow of gas from the substantially constant volume to a region of ambient pressure.

Abstract: A fluid regulator including, in a housing, a nozzle flapper mechanism, a diaphragm displaceable by the nozzle back pressure of the nozzle flapper mechanism, a valve body for controlling fluid communication through a fluid passage in accordance with displacement of the diaphragm, and a sensor for picking up a change in output fluid pressure from the fluid passage as a change in an electric signal. The nozzle flapper mechanism includes an electrostrictive element positioned closely to the nozzle of the nozzle flapper mechanism. Displacement of the electrostrictive element with respect to the nozzle is controlled by a differential signal resulting from comparison between an electric input signal and an electric signal from the sensor. The nozzle back pressure is varied dependent on the displacement of the electrostrictive element for thereby displacing a valve body in the fluid passage until the valve body is brought into equilibrium.