Abstract: The present invention pertains to an air cylinder (10) in which flow rate controllers (24, 24A) are built into a head cover (14) and a rod cover (16), said flow rate controllers (24, 24A) being provided with a first flow rate adjustment part (28) connected between a port (14a, 16a) and a cylinder chamber (12c), a second flow rate adjustment part (32) provided adjacent to the first flow rate adjustment part (28), and a pilot check valve (38) connected in series to the second flow rate adjustment part (32). In response to the pressure of pilot air, the pilot check valve (38) switches between a state in which the passage of exhaust air from the cylinder chamber (12c) is permitted and a state in which the passage of exhaust air is prevented.

Abstract: A flow rate controller and a drive device are provided with a first flow passage connected between an operation switching valve and an air cylinder, and that supplies air to and discharges air from a cylinder chamber of the air cylinder; a first flow rate adjustment part provided in the first flow passage; a second flow passage adjacent to the first flow passage; a pilot check valve provided at a point along the second flow passage; a second flow rate adjustment part connected in series to the pilot check valve at a point along the second flow passage; a pilot air flow passage, one end of which communicates with the operation switching valve and the other end of which is connected to a pilot port of the pilot check valve; and a third flow rate adjustment part provided in the pilot air flow passage.

Abstract: A system for automatically actuating a hydraulic accumulator—useful for oil collection systems—capable of operation while maintaining a zero or near zero draw of electrical energy.

Abstract: A pneumatic control device of auto door includes a first directional control valve configured to control a direction of a compressed air supplied to a door cylinder for opening and closing a door, a door detection sensor configured to detect an open/close state of the door, first and second exhaust lines respectively connected to first and second outlet ports of the first directional control valve, and second directional control valves installed in the first and second exhaust lines respectively to operably exhaust the compressed air exhausted from the first and second outlet ports according to an emergency stop signal, and capable of changing positions to reduce an exhaust speed of the compressed air in case that the door is not completely open or closed when an operation signal is generated after the emergency stop signal.

Abstract: Various embodiments of the present disclosure provide powered fastener driving tools and clean lubricants for powered fastener driving tools that reduce contaminant, residue, and deposit buildup or accumulation in the powered fastener driving tools, and thus reduce necessary maintenance for such powered fastener driving tools (or increases the time intervals between such necessary maintenance of powered fastener driving tools).

Abstract: A method for operating a valve device for supplying compressed air to compressed air consumer includes the steps of: determination of a first fluid pressure in a first section of a fluid passage of a valve assembly, which extends between an inlet port, and a valve element, determination of a second fluid pressure in a second section of the fluid passage of the valve assembly, which extends between the valve element and an outlet port, determination of a flow value for the valve element from the two fluid pressures and of a flow function, relating of the flow value with a presettable volumetric fluid flow rate or mass fluid flow rate for the pressurised fluid, which flow rate is provided for flow through the fluid passage, to a guide value and determination of a required actuating energy for an actuating device, and provision of the actuating energy to the actuating device.

Abstract: The present disclosure provides a hydraulic system for controlling a load. The system includes a housing defining an inlet, a first port, and a second port. The system further includes a spool valve and a proportional control element. The spool valve is in fluid communication with the inlet and the second port and the proportional control element is in fluid communication with the first port. The proportional control element can be controllable to exhaust fluid from the first port to a reservoir. In this arrangement, the proportional control element and the spool valve are controlled independently of one another.

Abstract: A device for flushing a hydrant includes a stem connected to a fluid valve of the hydrant and an actuation system including a biased translational system coupled to the stem, a compressed gas, and a normally-open gas discharge valve. An actuation system for flushing a hydrant includes a fluid, a piston assembly movable by the fluid, a manual bleed valve in communication with the fluid, and a biasing element at least indirectly biasing the piston assembly towards a stop position.

Abstract: A hydraulic valve device has a valve housing (10) in which an activating piston (16) is guided in a movable manner. The activating piston (16) is actuatable by an actuating device (18) and activates a pilot valve (20) to connect a fluid port (T) in the valve housing (10) to a fluid chamber (22) of a shut-off piston (24). The shut-off piston (24) activates at least one fluid-conducting connecting line (1, 2) of the valve device and has a fluid conducting control line (26) opening from the connecting line (1, 2) into the fluid chamber (22) of the shut-off piston (24).

Abstract: Vitrectomy probes and system related thereto are disclosed herein. The disclosure describes various example vitrectomy probes having an adjustable cutting port size. Various example features are described for adjusting the size of the cutting port. Further, the disclosure provides examples for adjusting the size of the cutter port while the vitrectomy probe is in operation.

Abstract: An independent metering valve (IMV) assembly is disclosed that includes a metering stem including an inlet. The IMV assembly also includes a hydro-mechanical control valve in communication with a fluid source and the inlet. The control valve also including a spool with a closed end and an open end. The control valve includes a biasing member that biases the control valve or spool towards an open position thereby establishing communication between the fluid source and the inlet. The control valve also including a load signal line providing communication between an outlet of the control valve upstream of the inlet and the closed end of the spool. Wherein high pressure in the load signal line allowing the control valve to move towards a closed position thereby overcoming bias of the biasing member and reducing flow to the inlet during a high pressure condition.

Abstract: A hydraulic system for a machine is disclosed. The hydraulic system has a source of pressurized fluid and a fluid actuator with a first chamber. The hydraulic system also has a first valve configured to selectively fluidly communicate the source with the first chamber. The first valve further includes a first element movable between a flow passing, at which fluid from the source flows to the first chamber, and a flow blocking position, at which fluid from the source is blocked from the first chamber and a second element configured to selectively drain a control passageway associated with the first element to cause the first element to move. The hydraulic system further has a proportional pressure compensating valve configured to control a pressure of a fluid directed between the source and the first valve dependent upon the pressure of the control passageway.

Abstract: A method for operating a hydraulic actuation system during a pressure sensor malfunction is provided. The hydraulic actuation system includes a pump, a reservoir, a first work-port and a second work-port, a valve system with individual orifices, a pressure sensor system, and a controller for regulating the hydraulic actuation system based on fluid flow demand and on determined pressure differences. The method includes detecting a malfunction of a pressure sensor for the first work-port, closing second and third orifices, and regulating the pump to generate fluid flow corresponding to maximum pressure generated by the pump. The method also includes assigning a value for the difference between pump pressure and the pressure of the subject work-port that is equivalent to a value within an attainable range for difference between the two pressures. Furthermore, the method includes regulating a first orifice and a fourth orifice in response to the fluid flow demand.

Abstract: A pneumatic nailer includes a tool housing enclosing a cylinder with a reciprocating drive piston, and having a trigger and a workpiece contact element both connected to a trigger valve. A valve cap is mounted to the housing and includes a cycle valve and a dump valve, each valve reciprocating in a respective valve chamber. The dump valve controls drive pressure for the drive piston, the cycle valve controls the return of the dump valve to allow piston return. The valve cap and the valves are constructed and arranged such that the piston is returned to a start position independent of positions of the trigger or the workpiece contact element.

Abstract: A hydraulic system for a machine is disclosed. The hydraulic system may have an actuator with a first chamber and a second chamber. The hydraulic system may also have a first valve, a second valve, a third valve, and an operator input device displaceable from a neutral position to generate a signal indicative of a desired movement of the actuator. The hydraulic system may further have a controller configured to open the first and third valves by amounts related to the signal to pass fluid, and open the second valve by an amount related to the signal to pass fluid when the signal indicates a desire for increased actuator velocity. The third valve may continue to open during opening of the second valve.

Abstract: This disclosure relates to a hydraulic system and method that converts the kinetic energy generated by the operation of a swing motor into hydraulic potential energy and reuses the hydraulic potential energy for swing motor acceleration. An accumulator can be provided for storing exit oil from the swing motor that is pressurized by the inertia torque applied on the moving motor via movement of an upper structure of a machine. The pressurized oil in the accumulator can be reused to accelerate the swing motor by supplying pressurized oil to the swing motor.

Abstract: A machine, such as a backhoe, has a series of components connected in series and moved by separate hydraulic actuators. A position estimator determines the present position of each component from the load acting on the associated hydraulic actuator and a velocity command for the component. For each component, a function parameter estimator uses the present positions of the components to derive a set of parameters that include a static structure load that the components exert on the associated hydraulic actuator, acceleration and deceleration limits for both directions of component motion, and a control bandwidth for the associated hydraulic actuator. The set of parameters for a given component is used to control the associated hydraulic actuator.

Abstract: A tripping control system for use with, for example, turbines, includes a block circuit having two or more redundant blocking valves disposed or connected in series within a pressure supply line to block the supply of hydraulic fluid within the pressure supply line and a bleed circuit having two or more bleed valves connected in parallel between the pressure supply line and a return or dump line to bleed to the hydraulic fluid from the pressure supply line. The blocking valves and the bleed valves are actuated by one or more control valves under the control of a process or safety controller which trips the turbine by first performing a bleed function using the bleed valves, which then causes the block function to automatically actuate. Pressure sensors disposed at various locations in the tripping control system provide feedback to the controller to enable the controller to test each of the block and bleed valves individually, during operation of the turbine, without causing an actual trip of the turbine.

Abstract: A valve assembly (2) forming a bridge circuit and a hydraulic actuator comprising at least one valve assembly (2) are disclosed. The valve assembly (2) is fluidly connectable between a fluid source (3) and a fluid drain (4). The valve assembly (2) comprises a first valve (8) fluidly connected between the fluid source (3) and a first diagonal point (12) of the bridge circuit, a second valve (9) fluidly connected between the fluid source (3) and a second diagonal point (13) of the bridge circuit, a third valve (10) fluidly connected between the first diagonal point (12) and the fluid drain (4), and a fourth valve (11) fluidly connected between the second diagonal point (13) and the fluid drain (4). The valves (8, 9, 10, 11) are such that in the case of a power cut off, flows of fluid away from the diagonal points (12, 13) are prevented.

Abstract: Between an air source and a first pressure chamber of a double-acting main cylinder having a length measurement sensor for measuring an acting position of a piston, a supply solenoid valve is connected; between the first pressure chamber and the atmosphere, an exhaust solenoid valve is connected; and between a second pressure chamber and the air source, a stop solenoid valve is connected. When a target acting position of the piston is inputted into a controller, the controller moves the piston to the target acting position so that a position measured by the length measurement sensor agrees with the target position by on-off controlling the solenoid valves. Upon reaching the target position, the piston is stopped and held in the stopped state by confining air within the pressure chambers.

Abstract: Methods and apparatuses to direct a drill bit of a directional drilling assembly are disclosed. The methods and apparatuses employ the use of bi-directional actuators that are capable of displacing a hybrid steering sleeve in positive and negative directions. The bi-directional actuators are capable of greater control and precision in their actuations than traditional “engaged-disengaged” unidirectional actuators, thereby allowing for more precise directional drilling operations. The bi-directional actuators are preferably driven by drilling fluids and may optionally be shielded to lessen the erosive effects thereof.

Abstract: A hydraulic actuator for a hydraulic servomotor 4 is disclosed. The hydraulic servomotor 4 has a first chamber 5 and a second chamber 6 associated therewith. The hydraulic actuator is connected to a fluid source 2 and a fluid drain 3, and it comprises a valve assembly arranged between the fluid source 2 and the fluid drain 3 to control fluid pressures in the chambers 5, 6. At least one auxiliary valve 11 is fluidly connected between the valve assembly and the fluid drain 3, said auxiliary valve(s) 11 being of a kind which is normally closed in a de-energized state. In the case of a power cut off the auxiliary valve(s) 11 will close, thereby preventing fluid flow from the valve assembly towards the fluid drain 3. This causes a servomotor piston member 12 to be hydraulically locked in its instantaneous position, thereby locking the hydraulic servomotor 4. The valve assembly may be designed without taking the locking function into consideration.

Abstract: In an electrohydraulic control unit for rotor blade adjustment of a wind farm via a hydraulic cylinder, the hydraulic cylinder has one piston chamber and one piston rod chamber. Via an inflow valve assembly, a pressure fluid connection can be established between the pump and the piston chamber, while via an outflow valve assembly, a pressure fluid connection can be established between the piston rod chamber and the tank. Each valve assembly has at least two parallel-connected switch valves, which open and can be closed in various combinations in order to establish a desired position of the hydraulic cylinder. This control unit makes precise regulation of the rotor blade possible.

Abstract: A hydraulic system is disclosed having a source of pressurized fluid, at least a one hydraulic actuator, and a first valve. The first valve has a first valve element movable relative to a first valve bore between a plurality of positions from a first position in which pressurized fluid is substantially blocked from flowing toward the at least one hydraulic actuator to a second position in which pressurized fluid is allowed to flow toward the at least one hydraulic actuator. The first valve element is configured to be selectively moved from a third position located between the first and second positions to a fourth position located between the third and second positions at least partially based on a pressure signal of pressurized fluid downstream of the first valve.

Abstract: The flow of fluid to a hydraulic actuator is controlled by a valve assembly which operates in different metering modes at various points in time for energy conservation. The metering mode to use is selected in response to the hydraulic load acting on the hydraulic actuator. Specifically, the present magnitude of hydraulic load is determined and compared to first and second thresholds. Below the first threshold only a first metering mode is activated, and only a second metering mode is activated above the second threshold. A combination of the first and second metering modes is utilized when the hydraulic load is between those thresholds, wherein the metering modes are used in proportion to a proportional relationship of the hydraulic load to the first and second thresholds. Using a metering mode combination in this manner smoothes transitions between the first and second metering modes.

Abstract: A valve assembly controls fluid flow between first and second ports of a hydraulic actuator and each of a supply line and a return line. A first electrohydraulic proportional valve is connected between the supply line and the first port, and second electrohydraulic proportional valve is connected between the supply line and the second port. A first counterbalance valve couples the second port to the return line and operates in response to pressure created by the first electrohydraulic proportional valve and the first port. A second counterbalance valve couples the first port to the return line and operates in response to pressure created by the second electrohydraulic proportional valve and the second port. Thus operation of the first counterbalance valve is slaved to the first electrohydraulic proportional valve, and the second counterbalance valve is slaved to the second electrohydraulic proportional valve.

Abstract: A distributed hydraulic system locates a control assembly, that has electrohydraulic valves and a electronic controller, adjacent the respective hydraulically powered actuator controlled by that assembly. The control assembly includes a manifold block with ports to that the pump, tank return and actuator fluid conduits connect. One or more pressure ports are provided on the manifold block at which to sense pressure at different locations therein. A controller housing, in addition to containing an electronic function controller, also contains a separate pressure sensor for each pressure port, and is mounted against the manifold block so that each pressure sensor connects to a pressure port. The manifold block also has a pair of exterior walls that extend on opposites sides of the controller housing to protect the electronic controller. Other features that facilitate distributing the hydraulic control adjacent the actuators are provided.

Abstract: A first fluid channel for operating an actuator and a second fluid channel for operating an actuator are connected to a boom cylinder, including a boom rod side line, a boom head side line. A first and second supply line and a first and second discharge line of each of the first and second fluid channels, respectively, are connected to first and second meter-in control valve and first and second meter-out control valves, respectively. When the boom operating lever is returned an operating position to a neutral position, a pressure vibration generated in each fluid channel for operating the actuators is detected, and respective meter-in control valves and meter-out control valves are controlled to dampen the pressure vibration in each fluid channel.

Abstract: A metering valve for a work machine hydraulic system is disclosed. The metering valve has an inlet and an outlet, a main poppet, and a solenoid-operated pilot element. The main poppet is movable to pass fluid from the inlet to the outlet, and to block fluid from the inlet to the outlet. The solenoid-operated pilot element is movable between a first position at which pressurized fluid from the inlet pressurizes a control chamber in communication with a control end of the main poppet to urge the main poppet toward the flow-blocking position, and a second position at which the control chamber is communicated with a drain to move the main poppet toward the flow-passing position. The metering valve also has a relief valve element configured to drain pressurized fluid from the control chamber to move the main poppet toward the flow-passing position in response to a pressure at the inlet exceeding a predetermined pressure.

Abstract: A hydraulic control system has an actuator with first and second chambers, first and second valves having elements movable to fill and drain the first and second chambers, and at least one sensor configured to generate a load signal indicative of a load on the fluid actuator. The system has an interface device movable to generate a desired velocity signal of the actuator. The system has a controller in communication with the first and second valves, the at least one sensor, and the interface device. The controller is configured to move the element of the first valve to a position based on the desired velocity signal and to move the element of the second valve to a position based on the load signal and a desired pressure within the second chamber.

Abstract: A valve is provided for a hydraulic system having a source of pressurized fluid, a fluid actuator, and a proportional pressure compensating valve. The valve has a bore in fluid communication with the source and the fluid actuator. The valve also has a valve element disposed in the bore and movable between a flow blocking position and a flow passing position to selectively fluidly communicate the source with the fluid actuator. The valve also has a valve signal passageway disposed within the valve element and configured to be in fluid communication with a pressurized fluid having a signal pressure indicative of pressure supplied to the fluid actuator. The valve further has first and second orifices disposed within the valve element in fluid communication with the valve signal passageway and the bore. The valve signal passageway is configured to communicate the signal pressure with the first and second orifices.

Abstract: A metering valve for a work machine hydraulic system is disclosed. The metering valve has a valve body with an inlet and an outlet. The metering valve also has a main poppet disposed within the valve body between the inlet and the outlet. The main poppet has a nose end and a chamber end, and is movable between a flow-passing position at which fluid flows from the inlet to the outlet, and a flow-blocking position at which fluid flow between the inlet and outlet is blocked. The metering valve also has a pilot element movable to selectively communicate the chamber end of the main poppet with a drain, thereby affecting movement of the main poppet between the flow-passing and flow-blocking positions. The metering valve further has a solenoid mechanism operable to move the pilot element. The position of the pilot element is affected by a fluid pressure at the inlet.

Abstract: A control valve for operating a fluid-actuated device includes a fluid inlet, a fluid outlet and a passage in fluid communication between the fluid inlet and the fluid outlet, the passage defining a longitudinal axis. A valve seat is disposed in the passage and includes an upstream diameter and a downstream diameter, the downstream diameter smaller than the upstream diameter. A ball poppet is positionable in a seated line contact position with the valve seat. The valve seat has a valve seat angle relative to a centerline of the longitudinal axis that is greater than an angle formed by the centerline and a line tangent to the ball poppet at the seated line contact position.

Abstract: A poppet valve assembly with a control chamber that can be fluidly connected to a number of different hydraulic ports via a pilot valve assembly. The poppet valve assembly includes a poppet valve member whose movement is controlled by filling or draining the control chamber, and which can be hydraulically locked into a given position by fluidly isolating the control chamber from any other hydraulic connections. The poppet valve member includes a control hydraulic surface exposed to fluid pressure in the control chamber. The poppet valve assembly may be part of a valve assembly that includes a plurality of poppet valve assemblies that operably control a hydraulic cylinder connected to an implement of a work machine.

Abstract: The present disclosure is directed to a valve system including a controller and a valve including a valve element and a valve bore. The valve element is selectively movable relative to the valve bore at least partially in response to a signal communicated from a controller. The communicated signal is at least partially based on a load on the actuator and a determined pressured drop. The determined pressure drop is at least partially based on a hysteretic filter.

Abstract: A hydraulic system having a source of pressurized fluid and a fluid actuator with a first chamber and a second chamber. The hydraulic system also has a first valve configured to selectively fluidly communicate the source with the first chamber and a second valve configured to selectively fluidly communicate the source with the second chamber. The hydraulic system also has a supply passageway and a signal passageway each disposed between the first and second valves in parallel. The hydraulic system also has a proportional pressure compensating valve configured to control a pressure of a fluid directed between the source and the first and second valves. The hydraulic system further has a fluid passageway disposed between the supply and signal passageways to fluidly communicate the supply and signal passageways.

Abstract: An adjustor for a secondary pump of a brake includes a stationary plate attached to the secondary pump, a cylinder attached to the stationary plate, a piston movable in the cylinder, a rod extended through the cylinder and connected to the piston, a handle connected to the cylinder, an inlet valve put on the handle, and an outlet valve put on the handle. Pressurized air can enter the cylinder through the handle and drive the piston and hence the rod while going in the cylinder. The inlet valve controls the inlet of the pressurized air into the cylinder through the cylinder handle. The outlet valve controls the release of the pressurized air from the cylinder through the handle.

Abstract: A hydraulic system comprises a pump having a fluid feed end a fluid release. Hydraulic actuator has an advance port and a retract port A directional converter is fluidically coupled between the pump and the hydraulic actuator. The converter has a housing having a plurality of fluid passages that terminates in a pump outlet port, a pump inlet port, a first actuator port, and a second actuator port. A plurality of valves is disposed within the fluid passages. The plurality of valves has a first position and a second position. In the first position, a fluid flow direction at the first actuator port is into said housing from the actuator and a second fluid direction and a second actuator port is out of the housing. When the switches are in a second position the fluid flow direction is out of the housing at The second actuator port.

Abstract: A hydro-pneumatic spring support arrangement, particularly for a vehicle axle with at least one hydraulic spring support cylinder arranged between vehicle chassis and vehicle axle, having a cylinder chamber and a rod end chamber each connected with at least one pressure accumulator and can be selectively connected by valve arrangements with a pressure source and a tank. To influence the ratio of the square of the spring rate to the axle loading and to make the spring rate conform to ballasting, vehicle, or operating conditions, the valve arrangement associated with the rod end chamber is provided with at least one first electromagnetic valve which connects the rod end chamber with the pressure source and is provided with a second electromagnetic valve which connects the rod end chamber with the tank. A pressure sensor is provided, particularly a rod end chamber pressure sensor, the signals of which are utilized for the control of the first and the second electromagnetic valves.

Abstract: In series between pump and tank are two throttle devices, one of which includes a controllable throttle valve having a piston, of which one side supports a valve head, which forms the boundary of an annular gap between an inflow duct and an outflow duct. A hydraulic control path extends from the inflow duct through the throttle opening to the tank, running through a precontrol bore in the piston. To prevent an unwanted leakage fluid stream, one end of the precontrol bore at the annular gap in the region of the inflow duct is positioned so that it remains opened for a closed annular gap, and the other end of the precontrol bore on the other side of the piston is arranged where the piston, in response to the controllable throttle valve being completely opened, pushes against a stop face and, in so doing, automatically closes this other end.

Abstract: Disclosed is an actuator system for positioning a piston within a cylinder and comprising a compressed air source, a positioner, and first and second pneumatic valving modules. The first and second pneumatic valving modules respectively comprise first and second volume boosters to amplify the flow of compressed air, first and second derivative boosters to alternately supply and exhaust compressed air into and out of the first and second ends at high flow rates, and first and second commutators to selectively allow the compressed air to flow respectively between the volume boosters and the derivative boosters. A safety valve opens at a predetermined pressurization level such that the first and second commutators may be energized. A volume tank provides compressed air to each one of the first and second pneumatic valving modules upon energization of the first and second commutators.

Abstract: The flow of fluid to a hydraulic actuator is controlled by a valve assembly which operates in different metering modes at various points in time. The metering mode to use in selected in response to the hydraulic load that acts on the valve associated with the hydraulic actuator. Specifically the load is determined and then compared to threshold levels associated with the different metering modes to choose the metering mode for use a given point in time.

Abstract: A fluid control system may include a pump, a tank, and an actuator. A valve assembly may be configured to control fluid communication between the actuator, the tank, and the pump. An energy recovery circuit, including a pressure transformer, may be fluidly coupled to the actuator in parallel with the valve assembly.

Abstract: In an electrohydraulic lifting control device (S) for stacker trucks, which comprises, for lifting control, an electrically operable three-way flow regulator (R1) in a lifting branch (1) between a pressure source (P) and a hydraulic cylinder (Z) as well as, for lowering control, an electrically operable two-way flow regulator (R2) in a lowering branch (2) which branches off from the lifting branch (1) and leads to the reservoir, a redundancy switching element (A) is provided, which is actively electrically operable between closed and open positions, said redundancy switching element (A) being provided between the control pressure circuit of the two-way flow regulator (R2) and/or the control pressure circuit of the three-way flow regulator (R1) and the reservoir (T).

Abstract: The present invention includes a system for providing an improved controlled airflow within a vacuum booster system. The system includes a vacuum booster assembly having a primary chamber and a secondary chamber, and an outer tube having a first end and a second end, the first end in communication with the secondary chamber of the vacuum booster assembly. The system additionally includes an airflow control assembly operably coupled to the second end of the outer tube, and an inner tube, concentric to the outer tube, having a first end and a second end, the first end operably coupled to the airflow control assembly, the second end in communication with the primary chamber of the vacuum booster assembly. In the system, air flows from the primary chamber of the vacuum booster assembly to the airflow control assembly within the inner tube and air flows from the airflow control assembly to the secondary chamber of the vacuum booster assembly within the outer tube.

Abstract: An actuator including a pneumatically distended elastomer membrane that is pressurized and depressurized using electrostatically actuated flap valves laminated onto a printed circuit board. The flap valves close only at zero pressure gradients and flows so that elevated closing and hold-off pressures are achieved. Fluid expelled from the elastomer membranes during collapse are vented through a wall of the actuator. An air jet object mover utilizes an array of the pneumatic actuators as valves to open and close air jet vents. A fiber optic micro-switch utilizes pneumatic actuators to position a mirror.

Abstract: A pneumatic control system is provided for positioning a piston within a cylinder and comprises a positioner for regulating the flow of compressed air into and out of first and second ends of the cylinder. First and second large boosters force compressed air into the respective first and second ends. First and second small boosters and first and second quick exhaust valves collectively exhaust compressed air out of the respective first and second ends. First and second small and large booster check valves interposed between the directional valve and the respective first and second small and large boosters are oriented such that the flow of compressed air through the signal lines and into the first and second small and large boosters may be blocked for increasing the sensitivity of the positioning of the piston.

Abstract: A hydraulic regeneration system for a work machine is provided. The hydraulic regeneration system includes a first hydraulic actuator having a first chamber and a second chamber, a second hydraulic actuator having a third chamber and a fourth chamber, and a source of pressurized fluid. A first directional control valve is disposed between the source of pressurized fluid and the first chamber of the first hydraulic actuator and the third chamber of the second hydraulic actuator. A second directional control valve is disposed between the source of pressurized fluid and the second chamber of the first hydraulic actuator and the fourth chamber of the second hydraulic actuator. An accumulator may also be used to store pressurized fluid and selectively supply pressurized fluid to increase the efficiency of the work machine.

Abstract: A control system for operating a hydraulic system includes a user input device which generates an input signal indicating desired movement of a hydraulic actuator. A mapping routine converts the input signal into a velocity command indicating desired actuator velocity. A valve opening routine transforms the velocity command into a flow coefficient which characterizes fluid flow through the valve assembly and from the flow coefficient produces a set of control signals designating levels of electric current to apply to valves within the valve assembly. A pressure controller regulates pressure in the supply line in response to the velocity command. When the hydraulic system has a plurality of functions, the control system adjusts each velocity command to equitably apportion fluid to each function when the aggregate flow being demanded by the functions exceeds the total flow available from a source.

Abstract: A fluid control system is disclosed that includes a first double-acting actuator and a second double-acting actuator. A first independent metering valve has a first control port connected to the first double-acting actuator, a second control port connected to the second double-acting actuator, first and second independently operable valves disposed between the inlet port and the first and second control ports, and a first check control mechanism having a main check valve between the inlet port and the first and second independently operable valves. The first check control mechanism controls the main check valve to allow the first and second actuators to operate in either an independent function mode or a regenerative function mode.