Abstract: A pressure support system having enhanced noise reduction and a valve assembly for use in pressure support system. The pressure support system includes a pressure generator having an inlet and an outlet. A first conduit defining a tortuous path is coupled between a gas source and the inlet of the pressure generator. A second conduit coupled to the outlet of the pressure generator delivers the flow of gas from the pressure generator to a patient. A valve assembly communicates gas from the second conduit to the first conduit to control the pressure or a rate of the flow of gas in the second conduit. By communicating gas from the second conduit to the first conduit, the noise associated with exhausting gas from the second conduit is muffled by the tortuous path of the first conduit.

Abstract: A solenoid spool valve includes a spool valve, a spring, and an electromagnetic actuator. The spool valve has a generally cylindrical sleeve provided with a fluid input port and a fluid output port and a spool supported in the sleeve for axial displacement to switch between said input and output ports. The spring abuts a first working face of said spool to energize said spool in a first axial direction. The electromagnetic actuator provides an axial drive force to a second working face of said spool in a second axial direction that is substantially opposite to said first axial direction. The first and second working faces are disposed axially inside of both axial end portions of a bearing, respectively, for slidably supporting said spool in said sleeve.

Abstract: A normally open hydraulic control valve includes: a linear solenoid unit; a spool driven by an output force of the linear solenoid unit to move forward; a valve body in which the spool is fitted; and a return spring for biasing the spool in a retreating direction. The valve body includes: a reaction force oil chamber for introducing hydraulic pressure, which presses the spool in a direction against a biasing force of the return spring, from the output port; and a damper oil chamber which suppresses vibration of the spool. The damper oil chamber is adjacent to the reaction force oil chamber with the third land portion of the spool therebetween. A slide gap which leaks and supplies oil from the reaction force oil chamber to the damper oil chamber is provided between the third land portion and the valve body.

Abstract: The invention relates to a control valve (10) for controlling the pressure and flow of hydraulic oil from or to the working connections (A, B) of a consumer. The pressure and the pressure flow are controlled by means of at least one sliding piston which can be actuated by at least one drive mechanism and which can be displaced in a slider hole and in co-operating annular channels. The invention is characterized in that the annular channels are symmetrically arranged, whereby a tank connection annular channel is arranged in the symmetrical centre point on a symmetrical axis. Annular channels associated with the working connections (A, B), pump-pressure annular channels, load-sensing annular channels and end-chamber annular channels are arranged behind each other on both sides. According to the invention, the latter can be connected to other channels.

Abstract: A solenoid control valve for use in actuation of a manual hydraulic clutch in a vehicle. The solenoid control valve has an electronically operated solenoid with armature and actuator rod displaced through a channel in the solenoid. A spool valve has a valve body that is coupled at one end to the solenoid. A spool is slidably disposed in the control channel. A first and second dampener chambers are located at the two ends of the spool. The dampeners function to improve the stability in the control system and balance the transient flow forces of the hydraulic fluid as it moves through the valve member. The spool also has a control portion located between the first end and the second end of the spool. The control portion allows the control portion to communicate with a supply, control and exhaust passages in the valve body.

Abstract: A pressure regulating valve, in particular a proportional pressure regulating valve, includes a valve body (1) with at least a pump connection (P), a use connection (A) and a tank connection (T). A piston (19), capable of being displaced by a controllable actuating device (29), is guided in the valve body (1). At the periphery of the piston, a recess (45) is formed and defines a peripheral annular gap (47) delimited by the control edges (49, 51) of the piston (19). In the piston (19), a passage (55) provides fluid communication between the front surface of the piston (19), subjected to the use connection (A) pressure, and the rear surface (35) of the piston (19), adjacent to a pressure chamber (37) located behind. The passage (55) of the piston (19) has, in the region proximate to the piston front surface, a restriction zone (57).

Abstract: A proportional solenoid valve or a camshaft adjusting device of motor vehicles has a valve housing and a piston movably arranged in the valve housing and provided with at least one pressure medium passage. A solenoid part is connected to the valve housing and acts on the piston. The valve housing has at least one working connector, a tank connector, and a pressure connector configured to supply a pressure medium into the piston. A leakage passage is provided that connects the pressure connector at all times to the at least one working connector.

Abstract: A damper device for a hydraulic control valve includes: a valve body; a damper oil chamber to which one end surface of a spool is faced; an oil reservoir chamber which is adjacent to the damper oil chamber with a partition wall therebetween; and an orifice provided in the partition wall to allow an upper portion of the damper oil chamber to communicate with the oil reservoir chamber. The damper oil chamber and the oil reservoir chamber are disposed in the valve body. The oil reservoir chamber is constructed by closing an opening of a recessed portion formed on an undersurface of the valve body with a top surface of the support member for supporting the valve body. In order to work the orifice in the partition wall by drilling from the opening of the recessed portion, an axis of the orifice is disposed to pass through the opening of the recessed portion. Thus, it is possible to eliminate need for post-treatment after working the orifice, thereby reducing the cost.

Abstract: Provided is a servovalve system for regulating fluid flowing within a fluid circuit. The servovalve system comprises a housing, a spool slidably disposed within the housing, a stepper motor operatively connected to the spool, and a controller and a position sensor electronically connected to the stepper motor. The controller generates driver signals representative of a desired amount of stepper motor rotation in order to cause the stepper motor to effectuate spool motion relative to the housing. The position sensor senses an actual amount of stepper motor rotation and generates a quantity of position signals representative thereof. The controller determines a signal ratio of the quantity of the position signals to the quantity of the driver signals and generates a diagnostic signal when the signal ratio reaches a threshold value representative of a predetermined level of mechanical resistance of spool motion relative to the housing.

Abstract: A linear control valve is disclosed regulating the flow of fluid to hydraulically activated devices, preferably a fuel injector and an engine compression release brake. The valve includes a valve member that is moveable between a first position in which the fuel injector is, at least partially, activated, a second position in which neither the fuel injector nor the engine compression release brake is activated, and a third position in which the engine compression release brake is activated. An electrical actuator providing two permanent magnets and two oppositely wound solenoid coils moves the valve member between its three positions. The polarity of the permanent magnets are oriented such that when the solenoids are energized, one solenoid coil pulls the valve member while the other solenoid coil pushes the valve member in the same direction.

Abstract: A mounting base portion having a plurality of solenoid valve mounting areas is formed on an upper face of a manifold base. A board having an opening portion is mounted onto the manifold base with the mounting base portion fitted in the opening portion and projecting upward from the board. Solenoid valves are mounted to the respective mounting areas. Solenoid portions of the respective solenoid valves extend over the board from the mounting base portion to cover an upper face of the board.

Abstract: A solenoid end cap assembly having a flat mating surface. The flat mating surface is a single planar mating surface and is designed to mate with a substantially flat mating surface of a valve control body. The solenoid, housed within the solenoid end cap, does not protrude past the flat surface and may form part of the substantially flat mating surface of the solenoid end cap. The flat mating surfaces of the valve control body and the solenoid end cap assembly eliminates the need for ring dowels in the assembly between the solenoid and the valve control body. This reduces manufacturing costs and assembly time. The flat mating surfaces also provide a uniform mounting surface for the solenoid from injector to injector. This increases performance characteristics, as well as increases thermal conductivity and magnetic conductivity characteristics.

Abstract: A solenoid actuated pneumatic valve assembly including a valve body having a pressurized air supply inlet port in fluid communication with a source of pressurized air, an outlet port adapted to be in fluid communication with at least one active pneumatically operated device, and a pass-through port. The pass-through port is adapted to be in fluid communication with and provide a pass-through of the supply of pressurized air to the inlet port of at least one other valve assembly such that the valves are mounted in series with respect to the supply of pressurized air. A latching assembly is also provided that is supported upon the valve body and is adapted to engage and be operatively retained within an aperture in a mounting plate.

Abstract: A fluid valve operator for moving a moveable valve element such as a disc (14) that is pressed forcefully against a surface of a valve frame (12). The valve operator includes first and second electric gear reduction motors (22, 24) that each has a movable driving member such as a rack (34, 36) that moves against a handle (20) of the valve element to move the valve element to a connect or disconnect position. Each motor withdraws its driving member from the valve member handle after moving the valve member. A default mechanism (90) moves the valve element handle to a preselected one of the positions, such as the disconnect position, when pressure of a fluid falls below a preselected level.

Abstract: A valve has a solenoid part and a valve part connected to the solenoid part. The valve part has a housing provided with connecting bores for a pressure medium, including a pressure connector and working connectors. The valve part has a piston and the solenoid part acts on the piston to alternatingly connect the working connectors to the pressure connector. The valve part has at least one groove extending alongside the valve part. At least one of the connecting bores is positioned in the at least one groove.

Abstract: A solenoid operated valve has a valve body with a plurality of ports and a spool slidable within the valve body to interconnect the ports in different combinations. An actuator drives the spool into several operating positions. The actuator has a solenoid assembly with an aperture within which first and second tubular pole pieces are received. An armature is able to slide within the two pole pieces and a push member projects from the armature abutting the spool. The push member is secured to a rolling bearing which has a plurality of rolling elements that roll against the pole pieces to reduce resistance to movement of the armature.

Abstract: The invention relates to a screw-in valve comprising a screw-in component, a sleeve with at least two connection openings to which a pressure load can be alternately applied, and a valve piston held for axial displacement in the sleeve for opening and closing a flow connection between the connection openings. In order to further develop the screw-in valve so as to reduce the risk of impairing movement of the valve piston on account of misalignment of the screw-in component, it is proposed, in accordance with the invention, that the sleeve be mounted so as to be axially immovable but displaceable and/or pivotable perpendicularly to the screw-in direction of the screw-in component relative to the screw-in component.

Abstract: The present invention relates to a pneumatic servo valve, and more particularly, to a pneumatic servo valve, wherein displacement of a spool due to flow force of a fluid is prevented by firmly holding the spool just after position control for the spool is completed, thereby ensuring the stability of a valve system, and an encoder is employed as a spool position detecting means.

Abstract: A microvalve having a generally planar plate valve body defining a chamber and a plate valve member movable in the chamber about a pivot axis that is perpendicular to the valve body to control the flow of a fluid through the valve body. The plate valve member defines a pair of opposite faces, a first duct therethrough provides fluid communication between the opposite faces to equalize fluid pressures acting on the opposite faces in the region of the first duct. The plate valve member also has a second duct therethrough that provides fluid communication between the opposite faces to equalize fluid pressures acting on the opposite faces in the region of the second duct. The first duct and the second duct are equidistant from the pivot axis.

Abstract: An electrically operated valve controls the flow of oil to and from a device that activates and deactivates a cylinder of a multi-cylinder engine. A first valve seat is between an inlet and a workport connected to the device and a second valve seat is between the workport and an outlet. A valve element engages the first valve seat when a solenoid actuator is energized. The valve element and the first valve seat cooperate to allow air to bleed from the inlet through the valve upon starting the engine, but prevent the oil from flowing in that path unless the solenoid actuator is energized. In one version of the valve, the valve element engages the second valve seat when disengaged from the first valve seat. In a second version, another valve element engages the second valve seat when oil flows through the first valve seat.

Abstract: Auxiliary manual operation on a bistable multiway valve is achieved with a valve member able to be reciprocated with the performance of a switching movement and furthermore operating device extending athwart the direction of the switching movement. There is a provision such that the operating device includes at least two mutually parallel plungers, which on operation act on second different flanks of the valve member, operation of one plunger locking the respectively other plunger.

Abstract: A rotary-acting valve is disclosed. In some embodiments, the rotary-acting valve is the pilot or first stage of a two-stage control valve and can be used to create an improved propulsion system for a missile. In the illustrative embodiment, the rotary-acting pilot valve comprises a movable rotor that resides in a chamber. The chamber includes three ports: a gas inlet port, a control volume port that couples to the second stage of a two-stage valve, and a gas vent port. The rotor in the pilot valve selectively pneumatically couples the second stage to either the gas inlet port or the gas vent port. When the second stage is connected to the gas inlet port, a piston (part of the second stage valve) moves to a blocking position in which it blocks the mouth of a thrust nozzle. When the second stage is coupled to the gas vent port, the piston moves to a non-blocking position with respect to the mouth of the thrust nozzle.

Abstract: At least one solenoid actuator and a valve are at least partially positioned within a body of an hydraulic device. The solenoid actuator includes at least one solenoid coil mounted to a stator that defines a guide bore in which a push pin moves between a first position and a second position. The valve includes a valve member that is operably coupled to move with the push pin. The push pin is attached to an armature that is positioned adjacent the solenoid coil. In order to increase the durability of the solenoid actuator, a relatively hard, nonmagnetic material is positioned between an inner surface of the stator that is made from a relatively soft, magnetic material and an outer surface of the push pin.

Abstract: The present invention relates to high speed control valves which are especially applicable for use in fuel injection systems. Producing a valve with a quick response time within acceptable packaging constraints and with a structure that allows the valve to be mass produced with consistent performance between valves is extremely problematic. By moving flow restrictions within the valve away from the valve seats, flow forces on the valve member can be reduced, while possibly also permitting a reduction in the necessary travel distance of the valve member to improve response time and other performance characteristics. The valve is particularly applicable in controlling hydraulic pressure applied to the closing hydraulic surface of a direct control needle valve in a fuel injector.

Abstract: A solenoid operated spool valve has a dampening reservoir formed at one end of the spool and which is ported for immersion in a fluid sump. The reservoir port is oriented vertically above the spool and a cap with an offset port is received over the reservoir port to baffle fluid flow from the reservoir and prevent the reservoir from draining when the port is fluid starved in the sump.

Abstract: A method for the manufacture of a valve having at least one valve opening surrounded by at least one valve seat and an elongated valve member able to be brought into different positions by pivoting. In order to adjust the switching stroke of the valve member the valve member is, for instance using a laser, locally and briefly heated until superficial plastification occurs so that in the direction of the pivoting movement performed in operation it experiences a permanent flexural deformation.

Abstract: Provided is a servovalve system having a fail safe apparatus adapted for switching the servovalve system between an operating position and a fail safe position. The servovalve system comprises a housing having a housing bore and a housing chamber, a spool moveably disposed within the housing, and a stepper motor connected to the spool and configured to vary the spool position for manipulating the fluid flowing within a fluid circuit when the servovalve system is placed in the operating position. A rotary-linear converter converts rotational motion of the stepper motor into axial motion of the spool. The fail safe apparatus includes a piston slidably sealed within the housing chamber and mechanically coupled to the rotary-linear converter. The piston is operative to move the spool from the operating position to the fail safe position upon a loss of fluid pressure in the housing chamber.

Abstract: A solenoid control valve for use in actuation of a manual hydraulic clutch in a vehicle. The solenoid control valve has an electronically operated solenoid with armature and actuator rod displaced through a channel in the solenoid. A spool valve has a valve body that is coupled at one end to the solenoid. A spool is slidably disposed in the control channel. A first and second dampener chambers are located at the two ends of the spool. The dampeners function to improve the stability in the control system and balance the transient flow forces of the hydraulic fluid as it moves through the valve member. The spool also has a control portion is located between the first end and the second end of the spool. The control portion allows the control portion to communicate with a supply, control and exhaust passages in the valve body.

Abstract: A solenoid valve includes a housing that establishes a supply port, a control port, and an exhaust port. A fluted bushing is statically affixed within the housing and a poppet slides within the bushing. The poppet is movable between a de-energized configuration wherein flow is prohibited between the control port and the exhaust port, and permitted between the control port and the supply port, plural partially energized configurations wherein flow is permitted between the supply port and the control port, between the control port and the exhaust port, and between the exhaust port and the supply port, and a fully energized configuration wherein flow is prohibited between the control port and the supply port and flow is permitted between the control port and the exhaust port.

Abstract: In a solenoid valve, a boss portion is formed integrally with an attracting portion of a stator core at an outer peripheral side of the attracting portion. The boss portion has a tapered outer peripheral surface and a tapered inner peripheral surface. A plunger has a communication passage, which extends through the plunger generally along a central axis of the plunger.

Abstract: A variable force actuator with a double needle poppet assembly includes a housing in which a first poppet and a second poppet are slidably disposed. The second poppet fits within the first poppet, and both poppets move when a nearby coil is energized to establish, in combination, a fluid flow configuration in response to the amount of energy applied to the coil.

Abstract: An electro-hydraulic valve is provided for use in a system to control flow and/or pressure within the system. An electro-hydraulic valve arrangement includes a housing and a valving mechanism disposed in the housing. The electro-hydraulic valve arrangement has a hold coil assembly connected to the housing adjacent to the valving mechanism. A force control member having a clapper face is positioned adjacent to the hold coil assembly and the clapper face thereof is maintained at a predetermined distance from a coil face of the hold coil assembly. A double precision adjustment mechanism is operative associated with the force control member and is operative to precisely control the distance between the coil face and the clapper face.

Abstract: In a manifold valve, a magnet is mounted to a spool of a solenoid valve, magnetometric sensors and connecting pins to be brought into continuity with the respective magnetometric sensors are provided in a first recessed portion formed in a casing, a sensor connector in a second recessed portion and a main wiring substrate connected to the sensor connector in a substrate housing chamber are provided to a manifold base, and the connecting pins are connected to the sensor connector to thereby electrically connect the magnetometric sensors to the main wiring substrate when the solenoid valve is mounted onto the manifold base.

Abstract: The invention relates to a 3/2-way valve for controlling the injection of fuel in a common rail injection system of an internal combustion engine, having a first switching position, in which an injection nozzle is in communication with a fuel return, and having a second switching position, in which the injection nozzle is in communication with a high-pressure fuel reservoir. To improve the function and quality of the injection, the 3/2-way valve includes a force-balanced control piston, and the control edge of the control piston is pressure-equalized by means of a blind bore.

Abstract: The invention relates to a pressure regulating valve, in particular a proportional pressure regulating valve. Said valve comprises a valve body (1) including at least a pump connection (P), a use connection (A) and a tank connection (T). A piston (19) capable of being displaced by a controllable actuating device (29), is guided in the valve body (1). At the periphery of said piston is formed a recess (45) which defines a peripheral annular gap (47) delimited by the ramps (49, 51) of the piston (19). In the piston (19) is provided a passage (55) for fluid communication between the front surface of the piston (19), subjected to the use connection (A) pressure, and the rear surface (35) of the piston (19), adjacent to a pressure chamber (37) located behind.

Abstract: In a proportional valve assembly, particularly for supplying compressed air on a glassware molding machine, a tubular body, having an axis and air inlet and outlet ports, houses a slide member which is slid axially along the axis, to open and close the inlet and outlet ports, by a linear actuator, on the one hand, and, on the other, by the reaction exerted by an elastic body and the compressed air; the elastic body being spaced apart from the slide member and connected to the slide member by a relatively moving device.

Abstract: An oil control valve is provided that comprises a housing, a spool movably disposed inside the housing, and a damping unit disposed between a distal end of the spool and an end wall of the housing such that an impact generated by a collision of the spool at the end of its travel decreases.

Abstract: An electro hydraulic servo valve assembly has a valve housing and a spool rotatably fitted to the inside of the housing. A number of ports are off-settedly provided along the length of the valve housing A plurality of orifices are provided along the length of the spool. The positioning of the orifices and the ports are such that only one set of orifices may be aligned with a corresponding set of ports at any one time. The spool has one end coupled to a servo motor so that the servo motor may drivingly rotate the spool relative to the valve body. The other end of the spool is open so that a fluid passage is established between the interior of the spool and any one of the orifices.

Abstract: Provided is a servovalve system having a fail safe apparatus adapted for switching the servovalve system between an operating position and a fail safe position. The servovalve system comprises a housing having a housing bore and a housing chamber, a spool moveably disposed within the housing, and a stepper motor connected to the spool and configured to vary the spool position for manipulating the fluid flowing within a fluid circuit when the servovalve system is placed in the operating position. A rotary-linear converter converts rotational motion of the stepper motor into axial motion of the spool. The fail safe apparatus includes a piston slidably sealed within the housing chamber and mechanically coupled to the rotary-linear converter. The piston is operative to move the spool from the operating position to the fail safe position upon a loss of fluid pressure in the housing chamber.

Abstract: A solenoid valve has an electromagnet subassembly and a pneumatic switching subassembly. A valve plug is mechanically associated with the electromagnet subassembly, the pneumatic switching subassembly includes a body enclosing the valve plug trapped between two sealing seating facing each other. The movement of the valve plug is controlled firstly by a spring located in a mobile core of the electromagnet subassembly through a pusher, and secondly by a means that forces the valve plug into contact on the upper seating of the pneumatic switching subassembly when the electromagnet is energized. The electromagnetic subassembly has four cylindrical pins at its assembly plane on the pneumatic switching subassembly, each cylindrical pin being provided with a transverse cavity formed on the generating line of the pin and terminating with a frustum of a sphere. The pneumatic switching subassembly includes four cylindrical cavities as its assembly plane with the electromagnet subassembly.

Abstract: An electrically actuated valve includes firstly a fixed core (1) accommodating, at least, one coil (2) in, at least, one housing and forming therewith, at least, one electromagnet of the electrically actuated valve. Further, this valve includes a body (4) forming with the fixed core (1) the sealingly tight carrier structure of the electrically actuated valve. Thirdly, this valve includes, at least, one movable core (3) placed between the fixed core (1) and the body (4). This electrically actuated valve is specially innovative in that the fixed core (1) is made as an unitary part from an injected ferromagnetic material and in that it combines several functions, in particular that of the pneumatic connection and/or of the electrical connection of the coil/coils (2). The decrease in the number of parts and the simplification of the design allow, accordingly, an additional miniaturization.

Abstract: A pressure control valve with a hydraulic system of an automatic transmission for a motor vehicle includes a valve body defining a control chamber, fluid ports communicating with the control chamber, and a valve spool having spaced pressure control lands located in the control chamber, the valve spool urged by a compression spring in an opposite direction from an electromagnetic force developed on the spool when a solenoid is energized. In one embodiment a control land is formed with a pressure feedback orifice that communicates a control port with a feedback chamber. The valve spool can be formed with different sized control lands. The feedback orifice is substantially insensitive to fluid temperature variation.

Abstract: A system, apparatus, and method of forming a hydraulic control valve system is provided. The system may include a hydraulic control valve, a removable mounting module, and a mounting assembly. The hydraulic control valve may have a valve body, the body having a function port, a supply port to allow for the supply of fluid to the function port, and a vent port to allow fluid to vent from the function port. The control valve may also have a gate assembly, the gate assembly having a gate, a seal assembly, and a roller bearings assembly. The seal assembly may include a seal carrier slidably mounted within the gate and a shear seal, to selectively direct hydraulic pressure to and from the subsea function. The hydraulic control valve may also include an actuation assembly for slidably moving the seal assembly, and a female coupling assembly integral with the hydraulic control valve body.

Abstract: A micro lock valve includes a cylinder forming an air chamber. One part of the cylinder is provided with an inlet port and an outlet port which communicate with each other through the air chamber, and the other part is provided with an exhaust port communicating with the air chamber. The micro lock valve also includes a plunger slidingly traveling in the cylinder, blocking up one of the inlet port or the exhaust port, and formed with a female screw thread in a traveling direction of the plunger. The micro lock valve includes a driving shaft having a male screw thread mating with the female screw thread and a driving motor rotating the driving shaft forwardly and backwardly. Accordingly, the micro lock valve maintains a normally closed state and a normally open state without consuming a large amount of electric power and is driven by low electric power for a long period of time.

Abstract: An auto-relieving pressure modulating valve includes a spool, a solenoid that shifts the spool in an energized direction, and a spring arrangement. The spring arrangement functions to shift the spool from a relieving position to a neutral position, in the energized direction, without energizing the solenoid.

Abstract: Improved low flow impedance flow control valves are disclosed in the present invention wherein spring valve means (12) captured between a valve spool (28) and a shoulder (30) are utilized for selectively metering a flow of fluid from an inlet port (18) to an outlet port (14) via a round edged helical orifice (82) formed between the open coils of the spring valve (12) as a function of the instant axial position of the valve spool (28) and the differential pressure therebetween. An improved method of controlling low impedance flow control valves is also disclosed in the present invention. The improved method provides better accuracy in controlling fluid flow through low flow impedance flow control valves through continually cycling a means for substantially interrupting fluid flow therethrough in a low frequency pulse width modulated fashion.

Abstract: A hydraulic pressure regulating valve for regulating a pressure in an automatic transmission of a motor vehicle, comprising a magnetic part which includes an electrically controllable coil, a coil core and a movable armature, a valve flange which is anchored on the magnetic part and has pressure medium guiding passages, a piston controlling a pressure in a passage connected to a consumer, the piston being loaded with the armature and controlling pressure medium connections between the passages, a diaphragm element which seals the valve flange relative to the magnetic part, a return passage, the diaphragm element having at least one pressure chamber which is hydraulically connected with the return passage, and a throttling device formed so that the pressure chamber is connected with the return passage through the throttling device.

Abstract: A solenoid control valve having a spool valve disposed within a valve body and an enlarged diameter, axially sealing land. An upper surface of the sealing land seats against an upper valve stop when the spool valve is in a first sealing position and a lower surface of the sealing land seats against a lower valve stop when the spool valve in a second sealing position, to provide sealing pressure in an axial direction relative to the movement of the spool valve. The control valve includes an actuating portion having a coil and an armature. The armature is in direct contact with the spool valve, preferably through a stem that extends through the upper valve stop. When the coil is not energized, a valve spring biases the spool valve to seat against the upper valve stop so that a source pressure is provided at a control port.

Abstract: A method for the manufacture of a valve having at least one valve opening surrounded by at least one valve seat and an elongated valve member able to be brought into different positions by pivoting. In order to adjust the switching stroke of the valve member the valve member is, for instance using a laser, locally and briefly heated until superficial plastification occurs so that in the direction of the pivoting movement performed in operation it experiences a permanent flexural deformation.

Abstract: An electrical command signal to a direct drive valve is compensated by a digital signal processor to cause the output hydraulic fluid flow from the valve to conform to a desired predetermined flow. The compensation is accomplished by measuring flow from the valve using a standard direct drive valve code. This flow is compared to a desired flow and the difference is taken on a point to point basis. A compensation is then calculated to change the command signal so as to cause the flow to be according to the desired flow.