Abstract: A servo valve includes: a fluid transfer valve assembly comprising a supply port and a control port (PA, PB); a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive means configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The drive means comprises an elongate member arranged to rotate in response to the control signal. The elongate member has a cam profile in the fluid flow path such as to vary the pressure acting on the ends of the spool as the cam profile rotates.

Abstract: A fuel-gas blending system receives low-pressure tank vapors and high-pressure flash gases from an oil production facility, boosts the pressure of the tank vapors, and blends the tank vapors and high-pressure gases together to supply fuel gas at a pressure and quality required by an onsite fuel-gas-powered generator. The quality of the supplied fuel gas is maintained by controlling the proportion of a high-pressure gas, such as separator gas, in the blend while the volumetric flow rates of the various gases vary in response to the real-time demands of the generator. The system operates in one of multiple modes in order to maximize the use of tank vapors. In one mode, all the gases pass through a low-pressure blower. In another mode, only the tank vapors pass through the blower, and the high-pressure gases are blended with tank vapors downstream of the blower.

Abstract: A fluidic component for generating an ultrasound signal is provided. The fluidic component includes a flow chamber, which can be flowed through by a fluid flow, which enters the flow chamber through an inlet opening of the flow chamber and exits from the flow chamber through an outlet opening of the flow chamber. The fluidic component has at least one device for forming an oscillation of the fluid flow at the outlet opening, the oscillation taking place in an oscillation plane, a separation device, which is designed to separate off a part from the oscillating fluid flow. The separation device includes an inlet opening, through which the oscillating fluid flow enters the separation device, and at least one first outlet opening and at least one second outlet opening, through each of which a part of the oscillating fluid flow exits.

Abstract: A vibrating wire piezometer pressure sensor system has (a) a vibrating wire connected to a pressure diaphragm; (b) a first electromagnetic coil (EMC) associated with the vibrating wire; (c) a second EMC associated with the vibrating wire; wherein the first EMC and the second EMC are wired in series and in parallel to a signal processor for converting an electrical signal to a pressure measurement.

Abstract: A fluidic component having a flow chamber allowing a fluid flow to flow through, said fluid flow entering the flow chamber through an inlet opening of the flow chamber and emerging from the flow chamber through an outlet opening of the flow chamber, and which flow chamber has at least one means for changing the direction of the fluid flow at the outlet opening in a controlled manner. The flow chamber has a main flow channel, which interconnects the inlet opening and the outlet opening, and at least one auxiliary flow channel as a means for changing the direction of the fluid flow at the outlet opening in a controlled manner. The inlet opening has a larger cross-sectional area than the outlet opening or the inlet opening and the outlet opening have cross-sectional areas that are equal in size.

Abstract: The invention relates to a servovalve for regulating the flow or pressure of a fluid, comprising: a control stage comprising at least one permanent magnet, at least one coil and an armature (13) configured to be able to be driven in rotation around an axial direction; a power stage comprising a filler plate (23) and a drum (22) mounted rotatably in said filler plate (23); a slender mechanical transmission shaft (31) extending along said axial direction and having a first end (31a) connected to said armature (13) and an opposite end (31b) connected to said drum (22); characterized in that said control stage further comprises a slender torsionally flexible tube (32) extending along the axial direction (8) around said slender transmission shaft (31) and having a first end (32a) secured with said armature (13), shrunk onto said first end (31a) of said transmission shaft (31), and an opposite end (32b) clamped by a tube support (33) extending as far as said filler plate (23), so as to form a flexible mobile assemb

Abstract: There is disclosed a flow control nozzle for controlling the flow of an incompressible fluid, the flow control nozzle having a flow area and comprising a deformable element comprising a shaped memory alloy (SMA) material wherein within a range of operating temperatures the SMA material is configured to reduce the flow area of the flow control nozzle as the operating temperature increases. The flow control nozzle is thus able to dynamically compensate for changes in operating temperature in order to maintain a constant flow.

Abstract: A pressure measurement device is provided. The pressure measurement device includes a pressure gauge having a hermetically sealed cavity. The cavity includes a pressure transferring media. The materials chosen for both the pressure gauge and the pressure transferring media are selected so that thermal effects on the pressure measurement device are minimized. The pressure transferring media includes a first material and a second material. The material for the pressure gauge and the materials for the pressure transferring media, in particular the first material and the second material, may be selected so that the volume of the pressure transferring media substantially fills the volume of the cavity of the pressure gauge within a particular temperature range. The pressure measurement device includes a pressure reading mechanism coupled to the pressure gauge and operative to convert a displacement of the pressure gauge to a pressure measurement reading.

Abstract: A hydraulic servo valve comprising a pair of opposing receiving ports, a piston disposed between the pair of opposing receiving ports and an actuator in contact with the piston. The actuator is configured to provide axial movement of the piston in response to being actuated. The piston comprises a pair of opposed openings that are in operable fluid communication with a respective one of each of the receiving ports, and the axial movement of the piston is configured to vary the amount of a fluid pressure communicated between a respective one of the openings and receiving ports.

Abstract: Servo-valve that controls fluid discharged from a nozzle discharge port by displacing the nozzle, and that drives an actuator. The servo-valve includes a receiver provided with a first inflow port into which the fluid discharged from the discharge port flows. At least either the discharge port or the inflow port is a non-circular opening formed such that the amount of change in the area of overlap of the discharge and inflow ports occurring when the nozzle is displaced from the initial position is larger than in cases where the discharge port and the inflow port are of circular form of the same area. The increased amount whereby the area of overlap between the discharge and inflow ports changes when the nozzle is displaced from the initial position lets the fluid flow into the inflow port more quickly, improving the response speed of the actuator.

Abstract: Servovalve with jet-type pilot stage including an ejector for ejecting a jet of fluid that is movable relative to a deflector adapted to generate a pressure differential that can be used to move a power distribution member of the servovalve, the ejector projecting radially from a column extending along a longitudinal axis and to which the ejector is fastened, being in fluid communication with a central passage of the column via which the ejector is fed with fluid, the column having a first end pivotably engaged in a part of the servovalve in the vicinity of a pressure feed thereof and via which the fluid is introduced into the central passage of the column, the column having a second end loaded by a torque motor to apply selectively to the column a rotation torque about the longitudinal axis in either direction relative to a rest position.

Abstract: A stand-alone gas-fired smoker constitutes a cabinet for holding food products to be cooked. A gas burner in the bottom of the cabinet is connected to a source of flammable gas by means of a variable gas valve. The gas burner heats the cabinet and thereby cooks the food products. An oil filled temperature sensing bulb is connected by means of a capillary tube to the variable gas valve in order to modulate the gas delivered through the variable gas valve to the gas burner and thereby modulate the temperature within the cabinet. A safety/ignition valve is connected between of the gas source and the variable gas valve. The safety/ignition valve is connected to a flame sensor, and the safety/ignition valve closes if the flame sensor senses that the gas burner has been extinguished.

Abstract: A flexure support apparatus for providing multiple axes support to reciprocating members for an energy conversion process includes a base having a sleeved opening disposed therethrough a central portion of the base and a plurality of apertures also disposed therethrough the base that are positioned outside of the sleeved opening, also included in a plurality of flexible finger assemblies that are positioned in an offset manner on opposing sides of the base. Further included is a pair of piston assemblies that are disposed within opposing ends of the sleeved opening being supported by the plurality of flexible finger assemblies, wherein the piston assemblies move in opposing and equal amounts in reciprocating movement within the sleeved opening being supported and controlled by the plurality of flexible finger assemblies, thus the pair of piston assemblies are able to do compressive work on a fluid within the sleeve without bearings or seals.

Abstract: Apparatus and methods described herein provide for boundary layer flow sensor and corresponding determination of the flow characteristics of an ambient airflow over an aerodynamic surface. According to one aspect of the disclosure provided herein, the boundary layer flow sensor includes a body configured for mounting within or below the aerodynamic surface, a pressure port configurable between an open state for taking pressure measurements within the boundary layer of the ambient airflow and a closed state that protects the pressure port from contaminants when not in use.

Abstract: A servovalve pilot stage (100) comprises a piezoelectric actuator (130) joined to a flow guide (132) and feedback wire (136) for connection to a main stage spool valve. The flow guide (132) and the piezoelectric actuator (130) may be integral.

Abstract: A winding device is provided with a rotor that rotates past an inner side and an outer side of an annular bead ring, which is fed in a circumferential direction, while holding a binding cord to wind the binding cord around the bead ring. The rotor includes a pushing member that elastically pushes the binding cord against the bead ring.

Abstract: A pilot stage for a jet type servo-valve, the pilot stage including an ejector for ejecting a jet of fluid and that is movable facing a deflector suitable for generating a pressure difference that can be used for moving a spool of the servo-valve. The ejector extends radially projecting from a column to which the ejector is secured and is in fluid-flow communication with a central bore of the column through which the ejector is fed with fluid, the column having a first end that is embedded in the servo-valve and through which the fluid is introduced into the column, and the column has a second end that is subjected to drive from a torque motor for selectively twisting the column in one direction or the other about a rest position.

Abstract: The disclosure relates to a method for operation of a position regulator for control of a pneumatic drive for an actuating member in a process installation. The position regulator has a pneumatic system with at least one nozzle/bounce-plate system, in which the bounce plates are in the form of piezo bending bars. For damped ventilation and venting of the pneumatic drive in the event of failure of the electrical power, it is proposed that the level of the electrical power supply be monitored and that, if a predeterminable limit value is undershot, the piezo bending bars of the pneumatics are adjusted via the input signals of the pneumatics such that the pneumatically controlled valves, which are subject to a characteristic, of the amplifier are open precisely just so far that a damped movement of the pneumatic actuating drive takes place to a predeterminable limit position at the desired movement speed.

Abstract: In a transducer of at least one electrical input signal into two separate magnetic output signals for a pneumatic actuator, a pressure input is connected to a source of pressure and a setting unit sets the pneumatic output signals by use of the electrical input signal. The setting unit provides the two pneumatic output signals separately and reciprocal to each other as a function of the input signal. At least one of the two output signals is connected to a pneumatic amplifier.

Abstract: There are provided a nozzle capable of enhancing the straight-advancing capability of jetted fluid to increase the back wash effect of a filter member, and a filter-type dust collector capable of effectively carrying out dust removal from a filter member with such a nozzle. To this end, the nozzle has a Laval nozzle section secured to the inside of an outer tube at its proximal end and a fluid guide section disposed at the leading end of the outer tube. The fluid guide section has a plurality of suction holes elongated in the flowing direction of the pressurized fluid. This nozzle is mounted on a pulse header tube of a dust removal device.

Abstract: A simplified torque motor which includes a plurality of parts defining appropriate alignment slots and grooves as well as openings for properly positioning the parts with respect to each other so that after being secured by appropriate fasteners, the torque motor may function as a first stage for the control of fluid through an appropriate valve. The various parts include a base carrying an armature, upper and lower pole pieces, permanent magnets, electromagnetic coils and shims disposed between the base and the lower pole piece to adjust the air gap between the poles of the upper and lower pole pieces. The shims are provided with appropriate slits to receive a tool for easy removal of the shim for air gap adjustment purposes.

Abstract: A variable displacement hydrostatic pump (11) having its displacement varied by a controller (17) in response to movement of a manual control lever (95) from a neutral position (FIG. 1). The vehicle has at least one other device (125,127) which provides an electrical output signal (133) indicating when operation of the pump (11) is "acceptable", in terms of either vehicle performance or operator safety. Associated with the control lever (95) is an input shaft (103) defining at least one stop surface (121,123). A solenoid assembly (109) has a moveable plunger (111), disposed adjacent the stop surfaces, and moveable between a retracted position (FIG. 4a) and an extended position (FIGS. 2 and 4), engaging one of the stop surfaces, when the output signal (133) indicates that operation of the pump is not acceptable.

Abstract: A system and method for controlling fluid mass-flowrate are provided. One embodiment of the method of the present invention essentially comprises generating in response to a requested mass-fluid flowrate a torque for controlling a torque-controlled valve to provide a flow of fluid from a supply to a remote space. Angular momentum is imparted to the fluid flow related to the actual mass-flowrate of the fluid flow. The angular momentum of the fluid flow generates a feedback torque therewith for counter-acting the controlling torque. The feedback torque is summed with the controlling torque to reduce the controlling torque as a function of the feedback torque whereby to form a hydromechanical closed-loop mass-flowrate servo-valve.

Abstract: A device for operating a servo drive having a positioning element controlled by a pressure medium. The device includes an electrical control unit generating a control signal based upon the position of the positioning element, a pre-control system connected to receive the control signal through an electrical control path and a main control system controlled by the pre-control system to operate the servo drive by moving the positioning element. A switching element is positioned between the electrical control unit and the pre-control system and opens the electrical control path prohibiting the transmission of the control signal upon detecting operation malfunction. Upon opening of the control path, the pre-control system acts to switch the main control system into a deventilation mode and said positioning element is moved into a predetermined "fail safe" position deventilating the positioning volume of the drive.

Abstract: A toy motion simulating apparatus for imparting motion to an operator controlled by a hydraulic control valve to proportionally direct hydraulic fluid from pitch, roll, and yaw fluid nozzles to respective pitch, roll, and yaw receiving chambers which are pivotably disposed with respect to the nozzles. A pitch and roll nozzle to proportionally direct hydraulic fluid to respective nose up and nose down pitch receiving chambers and clockwise and counter-clockwise roll receiving chambers and a yaw nozzle to proportionally direct hydraulic fluid to right and left yaw receiving chambers. The valve has a drain means for directing hydraulic fluid that doesn't flow into the receiving chambers out of the hydraulic control valve.

Abstract: A two stage valve assembly responsive to signals from a control system for supplying pressurized fluid to two load lines. The first stage includes a motor that directs pressurized fluid from a jet pipe toward a receiver assembly having two receiver ports and a bleedoff area disposed between and separating the receiver ports. The second stage assembly includes two spool/sleeve assemblies that control the flow of pressurized fluid to and from the two load lines. A drain line from the receiver assembly includes a pressure relief valve, which insures that both spool/sleeve assemblies will be servo-controlled at all times. Cartridges may be inserted in the spool/sleeve assemblies to linearize the relationship between input current from the control system and the output force of an unequal area actuator connected to the load lines.

Abstract: An improved fluid amplifier (39) is operatively arranged in a flow path extending between a source (28, 31) of pressurized fluid (P.sub.s) and a fluid return (38) at a return pressure (R). The amplifier has at least one fluid connection (34 or 35) to a load. The amplifier has a movable mechanical member (24) operatively arranged to control the pressure at, and flow with respect to, the load. The mechanical member has a displacement range encompassing a null position and an off-null position. The improvement broadly includes a variable-impedance orifice (42 and/or 43) arranged in series with the amplifier in the low path. The impedance of the orifice is varied such that the impedance is a maximum when the mechanical member is in the null position and is a minimum when the mechanical member is in off-null position, such that flow from the supply to the return when the mechanical member is in the null position will be less than the maximum flow between the amplifier and the load.

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 transducer which provides a regulated pneumatic output as a function of an electric control input includes a housing, a gas regulator, and a particle trap. The housing has a passage therein, the passage including an inlet for receiving a pressurized gas supply and an outlet. The particle trap is disposed in the passage and includes a trap plate and a trap nozzle which directs gas against the trap plate so as to remove undesired entrained particles from the gas before it reaches the gas regulator.

Abstract: A deflector jet servovalve including a fluidic amplifier constructed utilizing a plurality of laminae stacked one upon the other and bonded together to form an integral laminated structure. The fluidic amplifier includes a fixed ejector and a pair of receivers disposed opposed the ejector with a movable deflector disposed between the ejector and the receivers to deflect a jet stream emanating from the ejector. Conduit means is also defined in the integral laminated structure to supply fluid under pressure to the ejector and to receive any differential fluid output therefrom.

Abstract: A pneumatic servo comprises a motor having a shaft for rotation in response to an electrical signal. A cam is connected to the shaft for rotation therewith. The cam has an outer profiled periphery and opposite sides. A pneumatic nozzle having an opening for directing a flow of gas toward one side of the cam near the periphery, obscures the flow by different amounts as the cam rotates to create a back pressure in the nozzle comprising a pneumatic signal. A curved projection engages an opposite side of the cam, the projection being aligned with the nozzle opening and reducing oscillation excursions of the servo at gas pressures in the nozzle of above 12 psi.

Abstract: A pneumatic control valve (10) including a valve body (12) with fixed aperture plate (14), a movable redirector (18) and a force motor (26). The force motor (26) supports the redirector (18) adjacent to the aperture surface (16) of the fixed aperture plate (14) and is operable to move the redirector (18) back and forth along a line (28) without contacting the aperture surface. The aperture surface (16) has a plurality of apertures (70,72,74,76,78) with metering edges (124,126,128,130,132,134,136,138). The redirector (18) has redirector cavities (102,104,106,108) with metering edges (140,142,144,146). The force motor (26) deflects the redirector (18) to positions in which one or more of the cavities in the redirector connect two or more of the apertures (70,72,74,76,78) and direct fluid from some apertures and into other apertures. The location, length and shape of the metering edges can be varied as required to obtain desired fluid flow characteristics.

Abstract: A servovalve apparatus for use in fluid systems which comprises an elongate flexible valve element having a fixed end and a free, moveable end, and a conductive coil which surrounds at least a portion of the valve element adjacent its fixed end. An armature is secured to the valve element so as to be adjacent the conductive coil. Two permanent magnets, are provided adjacent the armature on opposite sides thereof, the magnets being positioned such that one magnet presents a north magnetic pole facing the armature and the other magnet presents a south magnetic pole facing the armature. A recieving plate is provided adjacent the free end of the valve element, the receiving plate having one or more channels formed therein for receiving fluid, and a bore for delivering fluid.

Abstract: A multiplexed hydraulic control system which avoids the use of a rotary multiplexer and thereby allows for random selection of the multiplexed outlet ports and variable dwell times for the respective ports. A single hydraulic input is multiplexed among a plurality of hydraulic outputs. A control system provides two types of signals: (1) modulation signals selected from a plurality of multiplexed input signals for producing a modulating hydraulic flow, and (2) selector signals for operating on the multiplexer means to route the modulated signal to the appropriately selected channel.

Abstract: A valve including a valve body, a torque motor mounted on the valve body and including an armature, a metering arm connected to the armature and extending into a first bore in the valve body, second and third coaxial bores in the valve body extending transversely to the first bore and being intersected by the metering arm, a pair of metering orifice members in the second and third bores with openings adjacent the metering arm, and fourth and fifth coaxial bores in the valve body having an axis which intersects both the metering arm and the axis of the second and third bores so as to permit viewing of the metering arm relative to the metering orifice members, a loose connection between the torque motor and the valve body to permit adjustment of the metering arm relative to the metering orifice members, and adjustment structure for permitting the axial and rotational orientation of the metering orifice members within the second and third bores.

Abstract: A servovalve apparatus for use in fluid systems which comprises an elongate flexible valve element having a fixed end and a free, movable end, and a conductive coil which surrounds at least a portion of the valve element adjacent its fixed end. An armature is secured to the valve element so as to be adjacent the conductive coil. Two permanent magnets, are provided adjacent the armature on opposite sides thereof, the magnets being positioned such that one magnet presents a north magnetic pole facing the armature and the other magnet presents a south magnetic pole facing the armature. A receiving plate is provided adjacent the free end of the valve element, the receiving plate having one or more channels formed therein for receiving fluid, and a bore for delivering fluid.

Abstract: Pressure gain compensation for a single-stage servovalve of the jet pipe type. The pressure gain compensation is provided by a separate reciprocally mounted spool having a feedback wire connected between the spool and the ejector jet. The spool has a differential pressure applied across the ends thereof from the receptors disposed opposed the ejector jet. Movement of the spool applies a force feedback to the ejector jet which is proportional to the pressure differential across the receptors and is opposite the force applied to the ejector by the torque motor to thereby compensate for pressure gain.

Abstract: A servovalve apparatus for use in fluid systems which comprises an elongate flexible valve element having a fixed end and a free, moveable end, and a conductive coil which surrounds at least a portion of the valve element adjacent its fixed end. An armature is secured to the valve element so as to be adjacent the conductive coil. Two permanent magnets, are provided adjacent the armature on opposite sides thereof, the magnets being positioned such that one magnet presents a north magnetic pole facing the armature and the other magnet presents a south magnetic pole facing the armature. A receiving plate is provided adjacent the free end of the valve element, the receiving plate having one or more channels formed therein for receiving fluid, and a bore for delivering fluid.

Abstract: A servovalve apparatus for use in fluid systems which comprises a flexible fluid conduit and a conductive coil which surrounds at least a portion of the conduit adjacent its upstream end. An armature is secured to the flexible conduit so as to be adjacent the conductive coil. Two permanent magnets, preferably formed of a rare earth metal material, are provided adjacent the armature on opposite sides thereof, the magnets being positioned such that one magnet presents a north magnetic pole facing the armature and the other magnet presents a south magnetic pole facing the armature. A receiving plate is provided adjacent the downstream end of the flexible conduit, the receiving plate having one or more channels formed therein for receiving fluid from the conduit.

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: A fluid control device comprising a pivotable member which has a planar major face and is mounted so as to enable pivotal motion about an axis parallel to the major face. The pivotable member including a fluid jet channel which directs a fluid jet towards a fluid receiving channel defined in a receiving member. The pivotable member is pivotally rotated about the axis by a device operable to pivot the pivotable member. This device may be an electromagnet disposed with its poles adjacent and parallel to the major face of the pivotable member. The motion of the pivotable member alters the relative positions of the fluid jet channel/channels and the fluid receiving channel/channels and thereby the quantity of fluid received by the fluid receiving channel/channels.

Abstract: An optical feedback loop system used in conjunction with an optical hydraulic servovalve. The system uses light energy from a single fiber optic bundle for expanding a gas in a pair of bellows. When one of the bellows is expanded a jet pipe connected to a servo fluid inlet is moved from a first fluid outlet to a second fluid outlet.

Abstract: An improved magnetic actuator for providing mechanical actuation representative of an input current has a housing that supports a coil surrounding a central core, and includes a diaphragm type spring above the central core. A cover of high magnetic permeability is mounted on the housing spaced from the diaphragm spring. A permanent magnet is mounted on the diaphragm spring in a predetermined pole orientation and the magnet extends through an opening in the cover. The permanent magnet provides flux through the housing and the core. Sensitivity is increased by using the permanent magnet to provide a magnetic flux in addition to that created by currents in the coil.

Abstract: An adhesive applicator receives liquid adhesive from an adhesive supply and has a pneumatically operated valve for controlling the flow of adhesive through the applicator to a sheet driven along a path past the applicator. A pneumatic proximity switch is located along the path for sensing the sheet as it approaches the applicator. Air from a pressure amplifier is provided to the pneumatically operated control valve of the applicator in response to the proximity switch sensing the presence of a sheet along the path. The proximity switch also can be connected to a pneumatically operated electrical switch that provides a signal to a logic and control unit for indicating to a machine operator that a paper jam exists in the event the sheet does not clear the proximity switch within a predetermined time interval.

Abstract: An electric signal to pneumatic signal transducer 10 comprises a nozzle 12 that accepts an input pneumatic supply and expels a gas stream 20. A receiver 16 that is spaced from the nozzle is positioned to recover at least a portion of the gas stream. The recovered portion constitutes a pneumatic output signal. The position of a deflector 14 relative to the gas stream is controlled by an electric input signal to aerodynamically deflect the gas stream expelled from the nozzle. The aerodynamic deflection affects the magnitude of the portion of the gas stream recovered by the receiver in a manner having a known relationship to the electric input signal, thereby generating a pneumatic output signal responsive to the electric input signal.

Abstract: A gas/oil high-low pressure control apparatus having a helical bourdon tube sensing a gas control pressure and a gap sensor connected to a pressure indicator and rotating between high and low set point flags in which the gap sensor controls a pilot actuated valve which in turn controls a gas supply. A pressure regulator is connected between the gas supply and the inlet to the gap sensor and the outlet of the gap sensor is connected to the valve. The gap sensor outlet also provides a regenerative feedback signal to the regulator for providing a snap acting closing operation of the valve when the gap sensor detects a set flag. The gap sensor is of a thermoplastic having an aligned inlet and outlet with a closible opening aligned with the inlet and the outlet for periodically cleaning the inlet and the outlet. The linkage between the bourdon tube and the gas sensor includes first, second and third links with a zero adjustment, a span adjustment and a linearity adjustment and an overrange protector.

Abstract: A single-stage servovalve has a movable member operatively arranged to selectively divide a continuously-discharged fluid jet between two receiver passages. The hydraulic output of the valve is the differential between the conditions in the receivers. In the event of a hard-over failure of the control system of which the servovalve is a part, a jet deflector surface becomes operative to create a substantially balanced hydraulic condition in the receiver passages, thus terminating control.

Abstract: A fluidic system for stabilizing movement of a body subject to oscillation at its natural frequency, such as a tank-mounted gun, with appropriate circuitry and controls for notch filtering control output signals at the natural frequency.

Abstract: In a flapper nozzle actuator system a radial outward flow turbine like flapper is used as the flapper. The angular velocity of the turboflapper is used to lift the turboflapper off a backplate towards a nozzle. The amount of lift off the backplate and hence nozzle outlet area is a function of the angular velocity of the turboflapper. An adjustable opposing torque on the turboflapper controls the angular velocity of the turboflapper and thus controls the flow rate.

Abstract: A two-stage miniature electrohydraulic servovalve including an electromagnetic positioner having a flexure tube mounted drive arm secured to and movable with an armature movable in accordance with a combined magnetic field resulting from both permanent magnets and an electrical signal fed to electromagnetic coils, a four-way hydraulic valve main valve stage including a valve body having a sleeve mounted therein with two annular, internal, axially spaced apart metering grooves, a metering spool having five lands alternating with four metering grooves positioned within the sleeve for controlled axial movement with respect to the sleeve, and end caps positioned over the ends of the sleeve and a jet pipe pilot stage including a jet pipe member secured to the end of the drive arm having a jet pipe nozzle aligned with the drive arm and a hydraulic fluid feeder passage which passage is disposed at right angles to the plane of movement of the drive arm, a resiliently mounted counterbalance positioned on the drive arm