Abstract: A valve for controlling fluids, having an in particular piezoelectric actuator unit (20) for actuating a valve member is proposed, which has at least one adjusting piston (19) and at least one actuating piston (16) that is guided in a valve body (15) and actuates a valve closing body, which valve closing body cooperates with at least one valve seat (24) embodied on the valve body (15) and in the closing direction disconnects a control bore (14) from an outlet chamber (25), from which a return conduit (26) branches off, wherein between the adjusting piston (19) and the actuating piston (16), a hydraulic chamber (18) is disposed, which transmits a motion of the adjusting piston (19) to the actuating piston (16). To keep the size of the actuator unit (20) small, the actuating piston (16), at least when the valve closing body is closed, is supported essentially in a hydraulically force-balanced fashion (FIG. 2).

Abstract: A valve for controlling fluids for reservoir injection systems, includes a hydraulic coupler and a piezoelectric actuator. The hydraulic coupler includes a first piston, a second piston, and a coupler chamber disposed between the two pistons. The piezoelectric actuator is in communication with the first piston. The first piston is embodied as substantially cup-shaped, and the second piston is disposed in a recess in the first piston. The coupler chamber is disposed between the second piston and an inner bottom region of the first piston. As a result, a hydraulic coupler of compact design can be furnished without reversing the direction of motion of the two pistons.

Abstract: A fuel injector, in particular an injector for fuel injection systems in internal combustion engines, has a piezoelectric or magnetostrictive actuator. The actuator operates a valve closing body by means of a valve needle, working together with a valve seat face to from a sealing seat. A fuel line leads from a fuel inlet connection to the sealing seat. A fuel line leads from a fuel inlet connection to the sealing seat. The actuator is tubular and surrounds at least some sections of the fuel line.

Abstract: A piezo valve having a flexural transducer unit which includes two flexural transducers adapted to be deflected in opposite directions. The flexural transducers are fixedly joined together at one terminal part of the flexural transducer unit with the formation of a common bearing section. The flexural transducer unit is pivotally mounted in relation to the housing. At least one flexural transducer serves for the control of a valve opening associated with it, the other flexural transducer being able to be biased by the application of a drive voltage toward a support face arranged in a deflection path in order to for instance to increase the displacement path of the other flexural transducer.

Abstract: A variable valve with an actuator that elongates upon application of an electrically-derived field. The valve includes an actuator comprising an actuator member made of a material that is elongated by an electrically-derived field. A coil surrounding the actuator member selectively applies an electrically-derived field to the actuator member. The valve further comprises a fluid flow path, an opening in the fluid flow path defining a flow area, and a closure member movable by the actuator member from a closed or more closed position in which it is restricting some or all of the flow area, to an open or more open position in which it is restricting less of the flow area, to selectively alter the fluid flow rate through the opening.

Abstract: An apparatus and method for actuating a valve using magnetostrictive transduction is provided. A ferro-magnetic rod having giant magnetostrictive properties is operatively coupled with a hydraulic chamber. Application of a magnetic field to the ferro-magnetic rod generates strain in the rod and corresponding movement in a first piston, causing the fluid in the hydraulic chamber to become pressurized. The pressurized fluid forces a second piston to move, thereby actuating the valve.

Abstract: A fuel injector performs main fuel injection by raising fuel pressure in a nozzle chamber to lift a check valve member to a fully open position, and performs preinjection or microinjection by operating a solid state motor to lower a check stop so that when fuel pressure in the nozzle chamber is raised the check valve member is limited to lift a much smaller distance.

Abstract: A valve (105) controls fluid flow in a microfluidic system (100). The valve (105) has an input port adapted to receive fluid exerting a predetermined level of pressure on the valve (105) and an output port. The valve (105) has a variable sized aperture disposed perpendicular to the flow of the fluid (119). The aperture varies in size between a relatively small aperture (137) and a relatively large aperture (151). The small aperture (137) prevents the flow of the fluid (119) through the valve (105) responsive to a relatively high level of capillary forces between the fluid (119) and the valve (105) in the small aperture (137). The large aperture (151) permits the flow of the fluid (119) through the valve (105) responsive to a relatively low level of capillary forces between the fluid (119) and the valve (105) in the large aperture (151).

Abstract: A fuel injector (1), particularly an injection valve for fuel-injection systems of internal combustion engines, has a piezoelectric or magnetostrictive actuator (16). By way of a valve needle (5), the actuator (16) actuates a valve-closure member (4), which interacts with a valve-seat surface (7) to form a sealing seat. The actuator (16) has a tubular design, and encircles a transmission piston (19) that acts on a hydraulic transmission device (27).

Abstract: A fluid mass flow control apparatus, particularly useful for controlling low flow rates of fluids used in semiconductor manufacturing processes, comprises a first elongated flow tube connected to an inlet fitting and to a capsule like valve housing and a second elongated tube connected to the inlet fitting and the valve housing and including a flow sensor. The valve housing is connected to a magnetostrictive actuator including an elongated actuator member disposed in a conduit connected to the valve housing and serving as part of the fluid flow path through the apparatus. An electromagnetic coil is disposed about the conduit and the actuator and is responsive to energization to effect controlled elongation of the actuator to control the position of a valve closure member disposed in the valve housing. Adjustments to full-scale flow ranges of the apparatus may be obtained by inserting a tube or wire in the flow sensor tube to act as a flow restrictor.

Abstract: A valve for controlling fluids is described, wherein a valve closing member (13) divides a low-pressure region (16) in the valve (1) from a high-pressure region (17), and a filling device (19) is provided to compensate for a leakage quantity from the low-pressure region (16) by withdrawal of hydraulic fluid from the high-pressure region (17). The filling device (19) is embodied in a valve body (9) with a conduitlike hollow chamber (18) in which a solid body (26) is disposed in such a way that a gap (28) is formed between the solid body (26) and the valve body (9). The material of the solid body (26) has a coefficient of thermal expansion that is so much greater than that of the material of the valve body (9) that with increasing temperature, a viscosity-dictated increase in the volumetric flow around the solid body (26) is at least partly limited (FIG. 1).

Abstract: A system for performing fluid jet myocardial revascularization includes a catheter having a proximal region, a distal region, a lumen extending therethrough and a valve disposed in the lumen for allowing the passage of fluids in the lumen to create holes in the myocardium. A valve control means extends through the proximal region of the catheter to open and close the valve. In one embodiment, the valve also includes a biasing mechanism for biasing the valve in a closed position. The valve may be controlled using an electrically actuated device that is heated with an electrical current to open and close the valve. In one embodiment of the invention, the catheter has a wall that can be expanded within a guide catheter to anchor the catheter during revascularization.

Abstract: A pressure-reducing valve for a common rail fuel injection system as a variable restrictor has a valve needle, a super magnetostrictive member, which is disposed so that it faces the valve needle, and the like. The super magnetostrictive member extends toward the valve needle against force urged by a spring when a magnetic field is applied by supplying electric current to a coil wound around the super magnetostrictive member. Thus a lifting distance of the valve needle from a valve seat formed on a valve body is adjusted precisely and an opening area of a fuel channel provided by the variable restrictor is determined. Therefore, fuel pressure of the common rail is adjusted suitably at required values by controlling magnitude of the current provided to the coil.

Abstract: A valve for controlling fluids is proposed, which has a piezoelectric actuator (5) and a hydraulic pressure intensifier which transmits the stroke of the piezoelectric actuator (5). The hydraulic pressure intensifier has a pressure chamber (7) and a piston element (10) with a transmission surface area (12). The hydraulic pressure intensifier can actuate a valve member (18) that is connected to the piston element (10). A mechanical pressure intensifier is interposed between the hydraulic pressure intensifier and the valve member (18).

Abstract: A metering device and method for delivering fluid that employs a compensating element. The metering device has a housing defining a fluid chamber that contains a pressurized fluid. The-housing further encloses an actuating drive, a valve needle and a compensating element. The housing terminates at a housing opening for delivery of fluid to the outside of the housing. Fluid is delivered from the housing by moving the actuating drive which in turn displaces the valve needle in an opening direction. Upon displacement of the valve needle, the valve needle moves axially in the opening direction with little, if any, lift loss due to the compensating element. The compensating element further acts to compensate for shifting or movement of metering components due to external factors, such as varying thermal loads, aging effects, and settling effects.

Abstract: The invention disclosed is a direct driven, smart material actuated servovalve providing very high actuation control bandwidth for moderate to large flow systems. The servovalve is comprised of a valve body and a valve spool, a smart material element such as a piezoelectric, electrostrictive or magnetostrictive material, and a mechanical lever. The lever is mounted to a pivot support in the valve body and is positioned relative to the smart material element and valve spool such that expansion/contraction motion induced into the smart material element enforces motion on the first end of the mechanical lever. This motion is amplified by the lever at the second end of the lever and drives the end of the valve spool. The resulting amplified motion causes the valve spool to shift along its longitudinal axis of sufficient distance to afford high bandwidth valve spool positioning on large flow valves.

Abstract: The current invention relates to a fluid control valve. The valve includes a piezoelectric actuator (2), a stroke increasing mechanism (3), which increases the stroke of the piezoelectric actuator (2), a restoring element (4), and a valve element (5). The stroke increasing mechanism is embodied as a tilting lever (3) and the valve element (5) is integrated into the tilting lever, which achieves a high degree of system rigidity with a minimum number of parts.

Abstract: Disclosed is a microvalve suitable for use in high pressure applications such as refriigeration. The microvalve has a displaceable member that slides across an inlet port, thereby creating an orifice. A pressure-equalizing contour is positioned beneath the displaceable member and is in fluid contact with the inlet port. The pressure on the displaceable member from the inlet port is equalized by the pressure from the pressure-equalizing contour. Consequently, the microvalve can be configured with its inlet port and outlet port on opposite sides of the microvalve. Pressures in the x and y direction are also equalized because of recesses that permit fluid from the inlet to contact all faces of the displaceable member.

Abstract: A flow rate control valve comprises a piezoelectric actuator and a displacement amount-amplifying mechanism for amplifying a displacement amount of the piezoelectric actuator. An amplified displacement amount, which is amplified by the displacement amount-amplifying mechanism, is transmitted to a valve head. The valve head is operated to regulate a flow rate of a fluid passing through a communication passage for making communication between an inflow passage and an outflow passage of a valve body. The displacement amount-amplifying mechanism is provided with an input section and an output section which are displaceable along an axis, and a displacement-transmitting section which is tiltably displaceable by a predetermined angle.

Abstract: This invention is directed to a microelectromechanical valve having two or more diaphragms containing non-aligned holes to control the flow of fluids. Fluid flows through the holes in the first diaphragm and then must flow between the first and second diaphragm to reach the holes in the second diaphragm, whereupon the fluid is free to flow past the second diaphragm.

Abstract: A fuel injection valve, in particular an injection valve for fuel injection systems of internal combustion engines, has a valve closing body that can be activated by an activation device with the aid of a valve needle, the valve closing body interacting with a valve seat surface to produce a sealing seat, and the activation device having at least one piezoelectric first bending element for producing a valve needle lift of the valve needle, the first bending element bending when the activation device is activated. In this context, the bending element is made of a plurality of piezo elements stacked in a longitudinal direction of the first bending element, internal electrodes arranged between the piezo elements being oriented perpendicular to the longitudinal direction of the bending element.

Abstract: A fuel injector having a piezoelectric actuator, which activates a shutter to move the shutter in a work direction between a closed position and an open position; the piezoelectric actuator is housed inside a casing having an inner chamber insulated from the fuel, and an outer surface wet by the fuel.

Abstract: Fuel injector provided with a piezoelectric actuator, a valve activated by the piezoelectric actuator and regulating a fuel supply that flows in a working direction, and a mechanical transmission placed between the piezoelectric actuator and the valve; an expansion of the piezoelectric actuator displaces the valve in the working direction from a closed position to an open position in an opposite direction to that of the fuel outlet.

Abstract: A valve for controlling fluids is embodied with a piezoelectric actuator (3) for actuating a valve member (2) that on one end has a valve head (7), forming a valve closing member, that cooperates with a seat (8) provided on the valve body (6) for opening and closing the valve (1). On a side of the piezoelectric actuator (3) remote from the valve member (2), a hydraulic chamber (21) is provided, which communicates, via at least one hydraulic line (23), with a bore (5) of the valve member (2) that is sealed from the piezoelectric actuator (3), and into which bore a piston (20) connected to the piezoelectric actuator (3) can plunge; the hydraulic chamber (21) is embodied as a hydraulic spring, which with its spring force on the piston (20) connected to the piezoelectric actuator (3) act as the prestressing element and the tolerance compensating element. The valve is intended in particular as a component of a fuel injection valve.

Abstract: A valve means which comprises a control chamber in a valve housing and into which several fluid duct open. In the control chamber there is at least one pivoting control rocker member serving for the control of at least one of the fluid duct openings and able to be moved between two terminal positions, one pivotal position of such control rocker member being influenced by an electrically activated flexible element. The flexible element may act within the control chamber on an actuating part of the control rocker member. The latter is biased by spring means into a first terminal position, the flexible element engaging the actuating portion of the control rocker member in the electrically non-excited state mechanically free of stress and without any spring bias.

Abstract: With actuators according to prior art, it is known that, in the inactive region, which is required for contact purposes, irregularities in expansion occur. These produce cracks in the piezoelectrically inactive electrode region, which may occur at regular intervals. As a result of the irregularities in expansion, the stresses accumulate in the passively expanded regions, up to a level at which they are relieved by crack formation.

Abstract: A piezoelectric actuator includes a piezoelectric bending transducer, the first end of the bending transducer may be pivoted, while its second end, which is opposite to the first end, may be movably supported in a longitudinal transducer direction. Given a simultaneously large deflection path or bending lift, the actuator may attain a high restoring or working force. Thus, in the case of a valve piezoelectrically actuated by such an actuator, the sealing effect of a valve channel, which is closed or to be closed, may be significantly increased.

Abstract: A variable pressure valve apparatus has a case having a fluid inlet port and a fluid discharge port, a valve element for closing the fluid inlet port, a spring member disposed in the case for biasing the valve element to close the fluid inlet port, and a cam wheel for undergoing rotation to deform the spring member and thereby vary a biasing force applied to the valve element by the spring member. A feed ratchet is disposed in the case for undergoing movement to rotate the cam wheel. A shape memory alloy or a piezoelectric element undergoes extension movement to move the feed ratchet to thereby rotate the cam wheel to deform the spring member.

Abstract: The invention concerns an injection device having a fluid port (10), a control valve (12), a setting element (14), by way of which a region of a first face (24) of the control valve (12) can be acted upon with force, and a control chamber (30) provided on the side of a second face (26) of the control valve (12), whereby a compensating chamber (28) is provided on the side of the first face (24) of the control valve (12), the compensating chamber (28) is partially limited by the first face (24) of the control valve (12), and the compensating chamber (28) communicates with the control chamber (30). The invention also concerns a control valve as well as a method for injecting fluid.

Abstract: The invention disclosed is a direct driven, smart material actuated servovalve providing very high actuation control bandwidth for moderate to large flow systems. The servovalve is comprised of a valve body and a valve spool, a smart material element such as a piezoelectric, electrostrictive or magnetostrictive material, and a mechanical lever. The lever is mounted to a pivot support in the valve body and is positioned relative to the smart material element and valve spool such that expansion/contraction motion induced into the smart material element enforces motion on the first end of the mechanical lever. This motion is amplified by the lever at the second end of the lever and drives the end of the valve spool. The resulting amplified motion causes the valve spool to shift along its longitudinal axis of sufficient distance to afford high bandwidth valve spool positioning on large flow valves.

Abstract: A valve (1) for controlling fluids is provided with a valve member (2), which is axially displaceable in a bore (5) of a valve body (3) and has a valve head (6), forming a valve closing member, that cooperates with a seat (7), provided on the valve body (3), for opening and closing the valve (1). A piezoelectric unit (4) for actuating the valve member (2) and a tolerance compensating element (12) for compensating for elongation tolerances of the piezoelectric unit (4) and/or other valve components (3) are also provided. The piezoelectric unit (4) is disposed in terms of its action direction essentially at a right angle to the axial direction of motion of the valve member (2) and can be acted upon by electric current such that the piezoelectric unit (4) exerts a tilting motion on a control member (12) that serves as a lever arm and is operatively connected to the valve member (2).

Abstract: A fuel injector, especially an injector for fuel injection systems in internal combustion engines, has a piezoelectric or magnetostrictive actuator. The actuator, via a valve needle, activates a valve-closure member, which cooperates with a valve seat surface to form a sealing seat. The actuator can be actuated in a first direction of motion. In contrast, the valve-closure member can be moved by the valve needle in a second direction of motion (40) that is essentially perpendicular to the first direction of motion.

Abstract: The invention relates to a valve for controlling fluids, having a piezoelectric unit (4) for actuating a valve member (3), with which a valve closing member (12) is associated that divides a low-pressure region (16) at system pressure from a high-pressure region (17). The valve member (3) has at least one first piston (9) and one second piston (11), between which a hydraulic chamber (13) is embodied.

Abstract: A precision controlled fast valve includes a diaphragm, a piezo actuator, and a plunger. The plunger is adapted to engage the diaphragm to create a seal which closes the valve. The piezo actuator is attached to the plunger and adapted to receive control signals which define the distance and speed of travel of the plunger. A control signal is received by the piezo actuator which causes the plunger to rapidly travel to a first position which is proximate to the diaphragm but does not create a seal. A second control signal is received by the piezo actuator which causes the plunger to pinch the diaphragm and creates a seal (due to the blocked force generated by the piezo). Creating the seal without excessive forces reduces the wear on the seal, allowing longer intervals between maintenance.

Abstract: A valve for controlling liquids has a plezoelectric unit (3) for actuating a valve member (2) and has at least one control piston (7) and at least one actuating piston (10) for actuating a valve closing member (13). Between the control piston (7) and the actuating piston (10) is a hydraulic chamber (11), functioning as a hydraulic coupler. A graduated step-up is provided in such a way that the actuating piston (10) is displaceable for a first fraction of its maximum stroke length, and a cross-sectional area (A1) of the actuating piston (10), adjoining the hydraulic chamber (11), and a cross-sectional area (A3) of the sleeve (14) together at maximum correspond to the cross-sectional area (A0) of the control piston (7). A stop (34) for the sleeve (14) in the valve seat direction is provided in the bore (8).

Abstract: The present invention relates to a valve for controlling fluids, which has a piezoelectric actuator (2) that is disposed in an actuator bore (3). A hydraulic booster (11) and a bellows (5) are also provided. The bellows (5) is embodied such that it can absorb the axial stroke of the piezoelectric actuator (2). The bellows (5) is connected solidly to the piezoelectric actuator (2) and is also connected solidly to the actuator bore (3). This assures a fluid-tight seal of the actuator module relative to the other regions of the valve.

Abstract: A valve for controlling fluids, having a valve member (2), which is axially displaceable in a bore (7) of a valve body (6) and on one end has a valve closing member (8) that cooperates with a seat (9, 10), provided on the valve body (6), for opening and closing the valve (1); having a piezoelectric unit (3) for actuating the valve member (2); and having a tolerance compensating element (22) for compensating for elongation tolerances of the piezoelectric unit (3). The deflection of the piezoelectric unit (3) can be transmitted to the valve member (2) via a deflection element (20), and the piezoelectric unit (3) is disposed with its piezoelectric head (17) toward the valve member in the direction of motion of the valve member (2) essentially inside a length of the deflection element (20) and is connected to the deflection element via the tolerance compensating element (22).

Abstract: An ultrasonic apparatus and a method for injecting a pressurized liquid fuel by applying ultrasonic energy to a portion of the pressurized liquid fuel. The apparatus includes a die housing which defines a chamber adapted to receive a pressurized liquid and a means for applying ultrasonic energy to a portion of the pressurized liquid. The die housing further includes an inlet adapted to supply the chamber with the pressurized liquid, and an exit orifice defined by the walls of a die tip. The exit orifice is adapted to receive the pressurized liquid from the chamber and pass the liquid out of the die housing. When the means for applying ultrasonic energy is excited, it applies ultrasonic energy to the pressurized liquid without applying ultrasonic energy to the die tip.

Abstract: In the case of a piezoelectrically operable valve (1) with at least one valve channel (4, 5), which can be closed by means of a sealing element (14, 16) held on a piezoelectric bending transducer (7, 8), the bending transducer (7, 8) is held at both ends in the valve housing (2) to increase the sealing effect of the closed valve channel or valve channel to be closed (4, 5). In this case, a first end (7a, 8a) of the bending transducer (7, 8) is fixed in the valve housing (2), while the second end (7b, 8b) is guided movably in the longitudinal direction (12) of the transducer in a housing groove (11) on the opposite housing side (2b).

Abstract: A microactuator device includes a base with at least one electrode pad and a permeation membrane. Permeation membrane is typically a water-permeable membrane that is able to deform by applying an electric charge to the electrode pad. The actuator device can be incorporated into valve assembly to open and close the valve. The valve assembly can have a reciprocating valve member operated by the deforming of the water-permeable member. Alternatively, the valve assembly can have an opening positioned to cooperate with the water-permeable membrane so that the deformation of the membrane closes the opening.

Abstract: An electrically controllable valve comprising at least one input port (13) and one or more output ports (12, 14), at least one sealing means (17, 18) being arranged to control the flow of a fluid between said input port and at least one of said output ports, said valve comprises one or more piezo-electric actuators (26) arranged to control the state of said sealing means, whereby the flow of fluid through said valve may be electrically controlled.

Abstract: A valve for use in laminated plastic microfluidic structures. The valve comprises first, second, and third layers of flexible material separated by first and second spacing layers to form microfluidic channels, and having an actuator section to selectively isolate the microfluidic channels from each other. The structure can also be used as a recirculating pump.

Abstract: A valve (1) for controlling liquids is embodied with a piezoelectric unit (3) for actuating a valve member (2) that is axially displaceable in a bore (8) of a valve body (9). One end of the bore (8) adjoins a valve system pressure chamber (18) defined by a sealing element (25), and its other end adjoins a valve low-pressure chamber (16), which has a leak drainage conduit (17) and which communicates with the valve system pressure chamber (18) via a compensation conduit (19), which has a pressure limiting device (20, 23′) and a filling device (23, 23′).

Abstract: An electrostrictive micro-valve is provided for modulating a fluid flow through a cannula or other narrow liquid conduit. The micro-valve includes a valve body having a passageway for conducting a flow of fluid, a valve element formed from a piece of viscoelastic material and disposed in the passageway, and a control assembly coupled to the viscoelastic material for electrostatically controlling the shape of the material to open or close the passageway. The valve element has a flat lower side connected to an inner wall of the passage of the valve body, and an upper side which faces an opposing wall within the passageway. The control assembly includes a pair of electrodes disposed over the upper and lower sides of the valve element. The electrode facing the lower side of the element is patterned so that localized electrostatic forces are generated across the viscoelastic material when a voltage is applied across both electrodes.

Abstract: A fuel injector includes an injector body that defines a nozzle outlet. A needle valve member is mounted in the injector body and moveable a lift distance between an open position in which the nozzle outlet is open, and a closed position in which the nozzle outlet is blocked. A piezoelectric actuator is mounted in the injector body and is moveable a piezo distance between an off position and an on position. A coupling linkage interconnects the needle valve member to the piezoelectric actuator such that a movement of the piezoelectric actuator is multiplied into a larger movement of the needle valve member.

Abstract: In one embodiment, a fluidic module, such as a microfluidic module, has a fluid-flow channel, an electroosmotic flow membrane positioned in the channel, and a cathode located on one side and an anode located on the other side of the membrane so that an electrolyte in the channel is transported through the membrane in the presence of a voltage. In another embodiment, the channel has a port, a flexible and fluid-impermeable diaphragm is added, the electrolyte is contained in a reservoir, and the membrane moves the bladder which acts as a valve for fluid leaving the channel through the port. In a further embodiment, electrolyte in a first reservoir is transported through the membrane to move the bladder to force fluid out of a second reservoir.

Abstract: A metering valve for metering fuel flow, the valve having a flow rate control member moveable along an axis to control the rate of flow of metered fuel through the valve, and a piezo-electric bending device bendable in response to a control signal so as to cause the flow rate control member to move a desired distance in a selected direction along the axis.

Abstract: A piezoelectrically actuable fuel injector comprising an accumulator volume within which a piezoelectric stack is arranged, the accumulator volume being arranged to receive fuel from a source of pressurized fuel, in use. The piezoelectric stack carrying an end member which engages a surface associated with a piston member so as to apply a retracting force to the piston member upon a reduction in the axial length of the piezoelectric stack, the piston member being operable to control fuel pressure within a control chamber. A volume is defined between the end member and the surface associated with the piston member. The volume is provided with a vent arrangement to permit fuel within the volume to flow to a low pressure drain.

Abstract: The invention relates to a micropump (10; 100) comprising at least a first plate (12), a second plate (20), an intermediate plate (18), a pump chamber (24), and inlet and outlet control members (28, 30). According to the invention, said inlet control member (28) is a non-return valve situated in the major portion of the thickness of said intermediate plate (18), being made of a moving member (40) and a membrane-forming portion (42) situated close to one of the plates (12, 20), connecting said moving member (40) to the remainder of said intermediate plate (18) and, by its resilience, enabling said valve (28) to move between a closed position and an open position, said moving member (40) having an orifice of limited volume passing therethrough.

Abstract: An improved microvalve device is configured to provide a more robust and durable operation to withstand the demands of various operating environments. The microvalve may comprise a valve seat and a diaphragm, with the diaphragm operated by an external actuator device, such as a bladder, through various mechanisms of actuation, such as direct and indirect mechanisms, that are separate from the microvalve. Through use of the various mechanisms of actuation, the actuator device is configured to apply forces on the diaphragm to suitably move the diaphragm to open and close the microvalve. The valve seat and diaphragm can be configured to provide the microvalve with a plurality of openings configured to permit flow thereinbetween. In addition, the microvalve may be configured to facilitate uni-directional or bi-directional flow.