Abstract: In a brake valve of the type in which a given ratio is maintained between a master pressure developed by a brake pedal and an actual brake pressure, an arrangement is provided for continuous, rather than stepwise, adjustment of this ratio. The brake valve includes a control piston which is subjected to the master pressure and which, by the displacement thereof, opens and closes connecting channels between an accumulator containing a primary pressure fluid and a brake, as well as between the brake and a fluid collecting tank. The control piston and a measurement piston apply counter forces to the arms of a balance beam whose lever ratio determines the degree of feedback of the instantaneous brake pressure to the control piston. A stop is provided in the path of the axis of the control piston, which limits the stroke of the piston, to prevent the overloading of the balance beam during abnormally high braking pressures such as occur, for instance, during panic braking.

Abstract: An improved liquid level controller having a housing, a body connecting from the rear of the housing for connecting directly to a vessel and to allow transmission of forces exerted by the displacer type float within the vessel responsive to changes in the level of liquid therein through the housing to a shaft having rotation about an axis extending horizontally and parallel to the rear of the housing, a torque bar pivotally mounted near its center to the body, means for imparting the rotational force of said shaft as an upward force to one side of the torque bar, means biasing the torque bar in a direction to maintain it in contact with and balance the force from said force imparting means, a control means having a supply and an output for actuating a liquid control, a proportional band mechanism including a lever pivotally mounted to said housing at one end and having a fulcrum member slidably mounted thereon for engaging said torque bar to transmit the slight motion of said torque bar in balancing the force

Abstract: A flapper actuated pilot valve is shown in 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 an upper end of the flapper element which extends through an opening in the valve body. The flapper element is supported within the upper chamber by means of a pressure sensitive diaphragm. The diaphragm area and primary and secondary sealing areas cooperate so that to provide an outlet gas pressure which is proportional to the external force supplied by the flapper upon the flapper element.

Abstract: A pneumatic device having a housing defining at least two chambers with one of the chambers having a nozzle located therein, a diaphragm separating the two chambers, main pressure connected to one of the chambers, an output line connected to one of the chambers for providing an output signal having a value dependent upon the interaction between the nozzle and the diaphragm, and a dampening apparatus located within one of the chambers and touching the housing, the dampening apparatus being flexible for permitting movement of the diaphragm to control the output pressure in the output line and to dampen noise.

Abstract: A pneumatic control system, control unit and method of making the same are provided, the system comprising a pneumatic source, a pneumatically operated device that produces an output, and a control unit for interconnecting the source to the device. The control unit has an input interconnected to the source and an output interconnected to the device, the control unit having a set point for selecting a desired output of the device. The control unit has a valve unit for controlling the interconnection between the input and the output thereof so as to regulate the pressure value in the output of the control unit. The control unit has a regulating unit for operating the valve unit to tend to produce an output of the device that corresponds to the selected output of the set point.

Abstract: A current-to-pressure (I/P) converter provides an output pressure as a function of the magnitude of a variable input DC current. The I/P converter includes a pressure sensor which produces a feedback signal representative of the output pressure. Based upon the feedback signal and the magnitude of the input DC current, an electrical control signal is produced which controls a device for varying the output pressure. The I/P converter also includes a circuit for generating a time-varying signal which is sent back over the current loop wires through which the input DC current flows. The time-varying signal provides an indication of whether the I/P converter is functioning properly. This permits diagnosis of possible causes of control system malfunctions without having to inspect the I/P converter itself.

Abstract: A pressure regulating transducer for providing a regulated output pressure in response to an electric input signal in which a proportional solenoid operates a valve, and the output pressure from the valve operates against the force generated by the solenoid to establish the position of a valve element for a regulated fluid output pressure. The position of the valve element will vary in response to flow changes, absolute pressure changes, and changes in the inlet or outlet pressures caused by leaks or restrictions, to maintain the designated outlet pressure for the input signal provided. Thus, a predetermined outlet pressure is maintained for each current input value, regardless of flow and/or absolute pressure changes.

Abstract: A fluid amplifier is used in a pneumatic transducer to provide a control output pressure in response to a pilot pressure provided as a function of a current signal. The fluid amplifier includes a valve that opens a pressure source to the control port and also controls pressure feeding through an exhaust passageway. The amplifier valve is provided with a negative feedback arrangement as the exhaust back pressure increases to stabilize the operation and make the amplifier less sensitive. The pneumatic amplifier is provided with a diaphragm arrangement that results in increasing exhaust back pressures tending to close the exhaust valve, rather than open the exhaust valve. The negative feedback makes the valve more easily controlled and provides for more stable operation.

Abstract: Pressure fluid operated servo system method and apparatus including a servo valve operable by an input signal to effect a system output movement; and which servo valve is responsive to the time rate of input signal receipt to vary a gain ratio of system output magnitude compared to input signal value; and method of making such a servo valve.

Abstract: Pressure fluid operated servo system method and apparatus including a servo valve operable by an input signal to effect a system output movement; and which servo valve is responsive to the time rate of input signal receipt to vary a gain ratio of system output magnitude compared to input signal value; and method of making such a servo valve.

Abstract: A regulator is provided in which the bias which urges the unseating of the regulating valve is a piston having a plurality of radial working surfaces, each in its own separate pressure chamber. The chambers are connected to the inlet selectively, singly or in combination, by solenoid valves. The unseating of the regulating valve is opposed by the outlet pressure which works on the entire back side of the piston. In the preferred form a relationship exists between the relative sizes of the individual piston working surfaces so that all the possible outlet pressures attainable by the regulator are equispaced, all the way from 0 psig to the highest regulated pressure.

Abstract: A pneumatic servo assembly including a back pressure nozzle and an electric motor operating a flat spiral cam variably restricting the nozzle. A nozzle clamp exerts a drag on the cam so that a constant pneumatic output is maintained if an electrical failure occurs.

Abstract: In a pneumatic position controller for controlling the position of a pneumatic servomotor (10) to a value determined by a pneumatic command pressure, the command pressure acts through a movable wall member (30) on a pivotable balancing member (40). The balancing member (40) controls through a baffle plate (52) the outlet nozzle (56) of a pneumatic amplifier (24). The balancing member (40) is axially spaced from a feedback lever (44), with aligned pivot axes. A helical torsion spring (50) has one end attached to the balancing member (40) and the other end attached to the feedback lever (44). The feedback lever (44) is rotatable by the servomotor (10). An advantageous and compact construction permitted by the use of the helical torsion spring (50) is described.

Abstract: A pneumatic controller for use in controlling airflow in a conditioned air distribution system is adjustable to accommodate different types of damper actuation and thermostats in different systems. The four-function controller can be manually reconfigured to be a direct acting/direct reset controller, a reverse acting/reverse reset controller, a direct action/reverse reset controller or a reverse acting/directing resent controller, all using a single diaphragm valve responsive to differential pressure between total air and static air inputs. A reset unit on one end of the controller can be mounted in four different positions, two upright and two inverted, to provide the four functions, with total air and static air inputs being reversed in position when the controller is in a reverse acting mode. A differential pressure responsive valve at the heart of the system is controlled by a spring which can act as either a tension spring, for direct acting, or as a compression spring, for reverse acting.

Abstract: A switching valve has at least one plate-shaped piezo-electric element having a free end which is supported in a sealed chamber, at least two fluid directing nozzles arranged to be opened or closed due to the position of the free end of the piezo-electric element and a fluid output passage communicating outwardly from said sealed chamber. An electric-pressure converter uses the switching valve, a pilot relay for converting a fluid pressure signal delivered from the output passage into a standard air pressure signal, a pressure sensor for converting the pressure signal from said pilot relay into an electrical signal, pulse-width modulating means for providing a pulse-width modulated signal, which corresponds to the deviation between the electrical signal from the pressure sensor and an external reference electric signal, for energizing the plate-shaped piezo-electric element in the switching valve.

Abstract: A pneumatic servo assembly (20) is provided for an electro-pneumatic control system (10) having closed loop control of a D.C. motor (12) operated from an error signal (56) developed from an electrical set point signal (4) and a pneumatic feedback signal (44). The feedback signal (44) is made compatible by a pressure transducer (26) monitoring the pressure output signal (22) of the pneumatic servo assembly (20) and establishing an electrical signal indicative thereof which is scaled, zeroed, and amplified by an amplifier unit (46).

Abstract: A pneumatic positioner is provided with a O-shaped vane that is movably supported at the ends of each of its legs. The nozzle has an air outlet proximate to and aligned with the vane. A nozzle, connected to a source of air under pressure, is attached to a disc for rotation about a central stem that extends through the O-shaped recess. The nozzle has an air outlet proximate to and aligned with the vane. The disc is rotatable about the stem to reposition the nozzle relative to the vane so that air issuing from the outlet of the nozzle can impinge upon the vane at different locations along the length of the vane, intermediate the ends of the legs of the vane. One end of the vane is attached to an input and feedback signal mechanism and the opposite end of the vane is connected to a relay center structure.

Abstract: A negative pressure control valve for generating a negative pressure has an inlet port communicating with a negative pressure source, an outlet port communicating with a negative pressure load, a diaphragm chamber with one surface defined by a diaphragm, and an atmospheric pressure chamber adjacent to the diaphragm chamber through the diaphragm and communicating with atmospheric pressure. The diaphragm holds a valve holding member. A solenoid operated mechanism which moves the valve holding member to a first or second position in accordance with an exciting current is disposed in the atmospheric pressure chamber. The valve holding member has a valve mechanism which communicates the diaphragm chamber with the atmospheric pressure chamber at the first position and seals a channel between those chambers at the second position. The solenoid operated mechanism selectively communicates the diaphragm chamber with the atmospheric pressure chamber.

Abstract: FIG. 2 illustrates a process and an apparatus for controlling a controllable magnitude as well as the use of the process, especially for controlling the throughput of pourable or flowable material (grain or water) in a flour mill. In this connection, a servo drive, constructed as a fluidic pressure drive (5', V'), is provided for controlling a servo element. The deviation, measured by a comparator (1'), is supplied to a discriminator (10), which then gives off a first discrimination signal (+U.sub.F, -U.sub.F) when the deviation has reached a first (lower) or second (upper) threshold value, the two threshold values lying within a range of small deviations about zero. In this range of small deviations, the pressure drive (5') is acted upon by transient micropressures (rapid pressure fluctuations with small peak values), the reversal points of the microfluctuations depending on the two aforementioned threshold values.

Abstract: A fluid flow pressure control valve includes a valve body having a chamber divided by a dashpot plate into an inlet chamber and a dampened flow region chamber. A diaphragm senses the fluid pressure forces in the chamber with an adjustable spring force acting to balance the fluid pressure forces exerted on the other side of the diaphragm. By varying the spring force with a follower piece, which moves axially along a stationary threaded shaft, the amount of fluid pressure necessary to balance the spring force can be selectively varied. The follower can be blocked from travel beyond selected locations by stops positioned on the valve housing and thus a plurality of desired pressure values can be reliably chosen. Fluid flow induced oscillations of the compact, easily installed valve are attenuated by a dashpot means which includes the dashpot plate with an aperture therethrough providing communication between the inlet chamber and the dampened flow region chamber.

Abstract: An electro-pneumatic transducer for converting an input current signal to a proportional output pressure signal is disclosed. The transducer includes housing means defining a chamber, the housing may be completely of magnetic material or may have a magnetic portion and a non-magnetic portion. The transducer includes an input communicating with the chamber for supplying a fluid under pressure thereto and having a valve seat with a nozzle opening therethrough, that portion of the nozzle forming the valve seat being formed of non-magnetic material while the remainder of the housing is of magnetic material or the valve seat may also be of magnetic material. The transducer also includes an output communicating with the inlet for allowing fluid supplied by the inlet to flow to a control device.Disposed within the chamber is a membrane means in operative association with the nozzle opening in the valve seat for varying the fluid flow through the nozzle opening to thereby vary the fluid pressure at the output.

Abstract: A pneumatic control system, control unit and method of making the same are provided, the system comprising a pneumatic source, a pneumatically operated device that produces an output, and a control unit for interconnecting the source to the device. The control unit has an input interconnected to the source and an output interconnected to the device, the control unit having a set point for selecting a desired output of the device. The control unit has a valve unit for controlling the interconnection between the input and the output thereof so as to regulate the pressure value in the output of the control unit. The control unit has a regulating unit for operating the valve unit to tend to produce an output of the device that corresponds to the selected output of the set point.

Abstract: A microprocessor having input fluid brake control apparatus and output fluid brake application apparatus is provided wherein the output fluid brake application apparatus comprises a digital signal characteristic of a desired fluid braking pressure. The brake application apparatus comprises an improved fluid pressure regulator having a fluid pressure chamber for developing and maintaining a regulated braking fluid pressure. The improved regulator has valves selectively operable to brake application, release, and lap positions for selectively governing regulated fluid pressure in a braking device and in the fluid pressure chamber. A digital linear actuator having an axially operable shaft responsive to the digital signal is provided to actuate the valves alternately to application and release positions, the actuator being secured to a piston subject to pressure in the fluid pressure chamber on one side thereof and subject to pressure of a metering spring on the other side thereof.

Abstract: A control valve or system of control valves governs fluid flow by digitally comparing a feedback signal from a fluid control loop with a command signal corresponding to a desired flow rate in a high pressure operating fluid flow line. In the preferred embodiment, a control valve system, such as a pressure relief valve, is operated under the control of a digital computer. The pressure relief valve is operated at a control pressure to regulate flow in an operating hydraulic system. The control pressure chamber is coupled to a relief line through a control pressure reduction valve and to a control pressure enhancement valve which is in communication with the operating line of fluid flow. A feedback signal indicating actual control pressure, flow rate or load position is compared with a command control pressure, flow rate or position. Preferably, the results of several comparisons are averaged together to provide an error correction signal.

Abstract: A pressure translator for converting a process pressure into a pneumatic signal which can be transmitted and measured by a pressure measurement device at a remote location. The pressure translator provides isolation for the process and the measuring equipment but still translates the process pressure with very high accuracy. The pressure translator employs a balanced valve in cooperation with a forced balanced diaphragm.

Abstract: A pneumatic liquid level control apparatus and method providing both a snap-actor mode and a throttling mode by rotating a control means on the apparatus. The control means has a reciprocating valve means mounted inside which is operative in the snap-actor mode and which is inoperative when the control means is rotated to the throttling mode. The control means is mounted on the apparatus housing so that it can be moved between its snap-actor mode and its throttling mode by merely loosing screws for affecting the movement and then tightening the screws to begin operation.

Abstract: A fluid pressure regulating valve includes a diaphragm piston reciprocally movable within a valve housing, whereby undesirable diaphragm piston flutter is effectively dampened by use of a dampening member. The diaphragm piston separates a control chamber from an outlet chamber which is in communication with a fluid pressure receiving device. A selectively controllable solenoid valve controls the fluid pressure level in the control chamber. Differences in fluid pressure levels across the diaphragm piston result in the reciprocal movement, thereby, such movement being preconditioned to occur as a function of the fluid pressure level in the control chamber. An inlet valve and an outlet valve each communicate with the outlet chamber and are operated according to the position of the diaphragm piston. Furthermore, the inlet and outlet valves are connected by a connecting rod such that their operation is mutually dependent.

Abstract: An optical hydraulic control wherein the flow of hydraulic fluid is controlled by movement of a valve spool 12. Movement of the valve spool is initiated by a hydraulic pressure differential that is established by moving a control member 34 out of an equilibrium position. Movement of the control member from its equilibrium position is accomplished by illumination of a beam support structure 36 with an optical command signal. The control member 34 is returned to its equilibrium position after appropriate movement of a valve spool 12 by mechanical linkage between control member 34 and valve spool 12 or, alternatively, by modulation of the optical command signal.

Abstract: An electrical-pneumatic transducer includes a pneumatic relay in which the pressure of the air at the outlet varies in accordance with the back pressure of the air at a bleed nozzle in the relay. This back pressure is changed by the armature of a solenoid with the armature opposing the nozzle outlet and being urged toward the latter with a force responsive to a signal in the form of current flowing through the solenoid coil. The magnitude of the current is correlated with the magnitude of a variable condition. The force on the armature, which is a permanent magnet, is selectively set to calibrate the transducer by means of a second permanent magnet which is axially aligned with the armature and is adjustably movable toward and away from the latter.

Abstract: A diaphragm module for pneumatic control systems comprises at least a pressure comparing stage and a force/pressure transducer controlled by said stage. The design of said module comprises chambers in a housing divided by diaphragms, wherein the force transmission between the diaphragms is achieved by intermediately arranged diaphragm disks.

Abstract: A closed center four-way poppet actuator control device is incorporated into a pneumatic actuation system for controlling the movement of flight surfaces. The closed center four-way poppet actuator control device has a housing, a pair of two-way poppet valves in the housing, a rocker arm assembly mounted on the housing and connected to the pair of two-way poppet valves, and a diaphragm assembly also mounted in the housing and in contact with the two-way valves. A torque motor-driver assembly connected to the diaphragm assembly actuates the two-way valves as determined by control signals. The rocker arm causes the two-way valves to function oppositely each other: one allows high pressure gas to be input to a lobe motor actuator while the other allows gas to be output from the lobe motor actuator. Each two-way valve has a cylindrical poppet valve for inletting the gas to the actuator and a disk poppet valve for outputting the gas from the actuator to a vent.

Abstract: A pinch sleeve valve having controllable opening positions regardless of internal sleeve pressure is disclosed. In the past it has not been possible to use a pinch sleeve valve as a control valve because a variation in pressure within the sleeve has affected the opening of the sleeve. The present valve comprises a flexible sleeve with a passageway therethrough, the sleeve having variable positions from a round cross section when fully open, to a collapsed cross section when closed. A rigid pressure sealed housing contains the sleeve and a sensing probe is connected to the sleeve which senses whether the sleeve is fully open, partially open or closed. A valve positioner is connected to the sensing probe and has a control system to set opening positions of the valve regardless of variations in the internal sleeve pressure, the valve positioner controls supply fluid to the housing at a pressure higher than the internal sleeve pressure and sufficiently high to close the sleeve to the desired opening position.

Abstract: An electro-pneumatic control system (10) is provided having closed loop control of a D.C. motor (12) which is operated from a biased motor servo circuit (14) thereby eliminating the need for a negative power supply to provide bi-directional rotation. Closed loop control is provided by a feedback signal from a pressure transducer (26) monitoring the pressure output signal (22) of the mechanical servo assembly (20).

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 transducer for providing a modulated fluid pressure control signal having an electromagnetic stator operable in response to an electrical control signal to apply a magnetomotive torque to a rotary valve member for controlling fluid flow to and from a control signal chamber. A diaphragm senses the difference between the control signal chamber pressure and atmospheric pressure and is operable in response thereto for moving the rotor axially for varying the pole overlap and magnetomotive torque on the rotor.

Abstract: A transducer for converting an electrical current signal to a pneumatic pressure. A solid state element such as piezo-electric flapper element 48 is used to vary the pressure drop through a nozzle 46 to provide a controlled pressure supply 28. A micro-power electronic circuit 59 controls the flapper. A solid state pressure sensor 24 detects the output pressure and provides a feedback signal for use in a negative feedback loop to control the flapper element. The flapper element may be triangularly shaped to reduce its responsiveness to relatively low frequency mechanical vibrations. In a exemplary embodiment, where intrinsic safety requirements limit terminal voltages, the flapper element is driven by a transconductance amplifier 94 which is powered through a shunt regulator 82 and a voltage tripler 92. The shunt regulator provides operating potentials which are derived from the signal current.

Abstract: A current-to-pressure converter receives an electrical input signal, such as a DC current, which is a function of a sensed parameter and which is indicative of a desired output pressure. An electrical-to-pressure transducer provides an output fluid pressure as a function of an electrical control signal. A function of the output pressure is sensed by a sensor which provides an electrical feedback signal which is a function of such pressure. The feedback signal is compared to a command signal derived from the electrical input signal. When a change in the sensed parameter occurs, the electrical input signal changes, which in turn results in a change in the command signal. The electrical control signal changes, thereby changing the output pressure until the feedback signal has changed sufficiently to return the command signal and feedback signal to a balanced state.

Abstract: A vacuum control valve includes a body having a vacuum inlet port, a vacuum outlet port and an atmospheric inlet port formed therein, a movable diaphragm type mechanism positioned within the body to define a vacuum chamber and an atmospheric chamber within the body wherein the vacuum chamber is in communication with the vacuum outlet port and the atmospheric chamber is in communication with the atmospheric inlet port and wherein the movable mechanism is movable in response to change in vacuum pressure within the vacuum chamber, a spring mechanism normally biasing the movable mechanism in a first position, a valve mechanism movable in association with the movable mechanism to thereby control fluid communication between the vacuum inlet port and the vacuum chamber, and between the atmospheric inlet port and the vacuum chamber and a regulating mechanism which further includes a cam mechanism rotatably mounted within the body and operatively associated with the spring mechanism wherein the cam mechanism is rotate

Abstract: The signal generating device provides both an electrical signal as well as a vacuum signal in response to the degree of opening of a throttle valve in a single body which has a vacuum inlet port and a vacuum outlet port as well as a atmospheric inlet port and which includes a movable diaphragm positioned within the body to define a vacuum chamber in communication with the vacuum outlet port and an atmospheric chamber in communication with the atmospheric inlet port with the movable diaphragm being responsive to the vacuum pressure within the vacuum chamber. The movable diaphragm is controlled by biasing springs and a valve member is associated with a diaphragm to control fluid communications between the vacuum inlet port and the vacuum chamber as well as fluid communication between the vacuum chamber and the atmospheric chamber.

Abstract: Disclosed is a fluid pressure and signal controller (60) that is adapted to regulate a fluid pressure regulator (16) by means of rotation of a cam (24) in response to rotation of a shaft. The controller is additionally provided with means for generating signals at one or more predetermined positions on the cam by movement of an output member (48) that is in contact with a profiled surface (40, 40') of a body member (38) which in turn is caused to move in response to movement of a cam follower (42) that is in contact relationship with the cam. Means are provided such as threads (51) are provided for adjusting the rotative position of the body member with respect to the position of the cam follower to account for any change in the initial position of the cam member and to enable more than one of the signal generation means to be positioned at different locations about the cam.

Abstract: A pneumatic process controller includes a nozzle mounted on a set point lever and a flapper with a connected process lever. The set point lever pivots the nozzle about a set point and input axis in response to set point adjustment. The process lever pivots the flapper about the same axis in response to the process variable. The nozzle and set point lever are mechanically separated from the flapper and process lever. Artificial effect upon the process variable from set point adjustment is eliminated.

Abstract: Control system which may be manually operable without disengaging, automatically or otherwise, the automatic features of the control system.

Abstract: In a fluid-pressure-operable relay valve a control piston works in a bore in the valve housing to control sequential communication between an inlet port and an outlet port, and between the outlet port and an exhaust port. An exhaust valve seating on the control piston is engageable with an exhaust valve member coupled to one end of a lever pivotally mounted in the housing, and a spring acts on the exhaust member to urge an inlet valve member towards an inlet seating surrounding the inlet port. Since the spring acts in opposition to fluid pressure at the inlet port, a relatively small `cracking force` is required to the urge the inlet member away from the inlet seating to open the inlet valve.In alternative constructions the inlet and exhaust members are combined into a single valve member which is urged directly by the spring towards the inlet seating.

Abstract: A pressure regulating valve for controlling a fluid pressure proportionally to an electric nominal value signal has a housing, a valve body in the housing, a proportionally operating magnet, a displacement pickup, a difference amplifier having inputs receiving a nominal value signal and an output signal from said displacement pickup, and an output connected with an input of the magnet, a valve cone associated with the valve body and loaded in a direction opposite to a fluid pressure as well as connected with a movable member of the displacement pickup, and a measuring spring loading the valve cone and fixedly abutting against the housing, wherein the valve member is movable in the housing and adjustable by an armature of the magnet against a force of the measuring spring.

Abstract: A Vacuum Signal Integrator (10) is typically employed for processing and combining multiple vacuum input signals into a single output signal within the environment of a truck or automobile. The integrator, in a typical application, would input vacuum signals representative of throttle position, RPM, altitude and coolant temperature and output a vacuum signal equivalent to the algebraic sum thereof to modulate a diesel EGR valve. Structurally, the integrator includes a housing (11) carrying several conventional vacuum motors (32, 34 and 36). Each vacuum motor applies a force to an idler bar (68) within the housing through reaction inserts (62, 94 and 96), which is representative of a monitored input signal. The individual forces collectively applied to the idler bar generate a resultant or moment force thereon which is linked to a conventional vacuum modulator valve (38) through a vent insert (118).

Abstract: A nozzle flapper valve provided with a nozzle, fixed throttle and flapper, characterized in that the flapper is formed to be cylindrical and has the cylindrical peripheral surface positioned on the axis of the nozzle so as to simplify the flapper moving mechanism and to prevent the flapper clearance from being clogged with dust in the fluid.

Abstract: A linkage for use in moment balancing measuring apparatus of the pneumatic type includes first and second pivotally mounted levers, the second lever being adapted to be acted upon by a measuring force and the first lever being adapted to be acted upon by a pneumatic force for balancing the linkage. According to the invention, apparatus are provided for adjustably varying the leverage ratio of the linkage, i.e., the ratio of the pneumatic force to the measuring force according to the particular application to which the linkage is put. The leverage ratio adjusting apparatus includes a rod-like member having one end rotatably attached to one of the levers and first locking means for selectively securing the rod-like member in a particular position corresponding to the particular application to which the linkage is put.

Abstract: A fail-fixed electrohydraulic servosystem in which a variation from a predetermined range of electrical input to the servosystem results in the output of the system being fixed in position. Fixing-in-position is accomplished by either hydraulically or mechanically locking a linkage to the output arm of the servosystem. Provision is also made for controlled drift and manual adjustment of the output after it is fixed in position.

Abstract: An electromagnetic coil 29 exerts an attractive force on a movable plate 30 of magnetic material, within which is mounted a ball 32 of non-magnetic material blocking the end of a passage 33 for the hydraulic fluid. The apparatus also comprises electronic means for supplying the coil 29 by means of a pulsed unidirectional current, the mark/space ratio and mean value of which are subject to control by an operating magnitude represented by an electric control signal. The apparatus can be utilized as a hydraulic potentiometer for the determination of a control pressure proportional to an electric control signal in a hydraulic control circuit of an automatic transmission of industrial vehicles.

Abstract: A fluidic servovalve is disclosed comprising a pilot stage valve having a pilot output for supplying a control fluid dependent upon a movable element, a boost valve responsive to the control fluid for supplying an output fluid, and a fluidic mechanical feedback connected from the output of the boost valve to the pilot stage valve, the fluid mechanical feedback having a ball-type motor responsive to the output fluid acting against it for positioning the movable element.