Abstract: A rack assembly for a cooking appliance includes a rack operable between a stowed position and a deployed position. At least one telescoping actuator is operable between a retracted position and an extended position. At least one connector has a first end coupled to a distal end of the telescoping actuator and a second end coupled to the rack. The rack is adjusted from the stowed position to the deployed position as the telescoping actuator adjusts from the retracted position to the extended position.

Abstract: A work vehicle includes: a hydraulic operation apparatus for operating an actuator; a main controller configured to generate a command current in accordance with an amount of operation of the operation apparatus; an electromagnetic proportional control valve configured to generate command pilot pressure in accordance with the command current; and a main valve configured to adjust a flow rate of hydraulic oil for operating the actuator based on the command pilot pressure. The electromagnetic proportional control valve is provided in a pilot oil passage that connects a pilot pump and a main valve, and configured to utilize hydraulic pressure supplied from the pilot pump to generate command pilot pressure. The operation apparatus is provided in an operation apparatus oil passage that is different from the pilot oil passage.

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: A double valve includes a first unitary valve assembly and a second unitary valve assembly. Each unitary valve assembly includes a first outlet port, a second outlet port, and a spool. A first pilot assembly and a second pilot assembly are coupled to the first unitary valve assembly and the second unitary valve assembly, respectively. A plate is coupled to the unitary valve assemblies and includes a passage to provide a first common outlet passage that is coupled to the respective first outlet ports of the unitary valve assemblies and a second common outlet passage that is coupled to the respective second outlet ports of the unitary valve assemblies. When the spools are in a first position, fluid flows through the first common outlet passage, and when the spools are in a second position, the fluid flows through the second common outlet passage.

Abstract: A stack valve 1 includes a boom direction switching valve 11 (first direction switching valve) connected to an unloading path 21 and a service valve 13 (second direction switching valve) connected to the unloading path 21 at the downstream of the boom direction switching valve 11. At changeover positions 11a and 11c at which the unloading path 21 on the upstream side is connected to one of the supply and discharge paths 29 and 30 and the other one of the supply and discharge paths 29 and 30 is connected to the unloading path 21 on the downstream side, the boom direction switching valve 11 is connected to a boom valve tank return path 27 which connects the other one of the supply and discharge paths 29 and 30 with the tank path 22.

Abstract: A hydraulic control system for an aircraft landing gear system has a hydraulic pressure source connected to a hydraulic fluid pressure transmission line, and at least one hydraulic actuator for extending and/or retracting a landing gear. A supply valve and a direction valve are arranged in series along the hydraulic fluid pressure transmission line. The supply valve and direction valve are adjustable to control the hydraulic pressure supplied to the at least one hydraulic actuator. The control system also controls uplock actuators.

Abstract: A hydraulic control system includes a source of pressurized hydraulic fluid for providing a pressurized hydraulic fluid, a main line circuit in fluid communication with the source of pressurized hydraulic fluid, a regulation valve in communication with the source of pressurized hydraulic fluid, the regulation valve moveable between a plurality of positions, and a lubrication valve in communication with the regulation valve, the lubrication valve moveable between a plurality of positions. A lubrication circuit and a cooling circuit are in communication with the lubrication valve.

Abstract: In a method for controlling a valve system controlling an actuator, the first direction of motion of the actuator is controlled solely by the first and the second valve series; or, its second direction of motion is controlled solely by the third and the fourth valve series; and an error caused by a fault situation in the control of the actuator is compensated for by using, for the control of the first direction of motion, also the third valve series, the fourth valve series, or both of them; or, an error in the control of the actuator caused by a fault situation is compensated for by using, for the control of the second direction of motion, also the first valve series, the second valve series, or both of them.

Abstract: A proportional pressure controller includes a body having inlet, outlet, and exhaust ports. A fill valve communicates with pressurized fluid in the inlet port. A dump valve communicates with pressurized fluid from the fill valve. An inlet poppet valve opens by pressurized fluid through the fill valve. An exhaust poppet valve when closed isolates pressurized fluid from the exhaust port. An outlet flow passage communicates with pressurized fluid when the inlet poppet valve is open, and communicates with the outlet port and an exhaust/outlet common passage. A fill inlet communicates between the inlet passage and fill valve, and is isolated from the outlet flow passage, exhaust/outlet common passage, and outlet and exhaust ports in all operating conditions of the controller.

Abstract: An anti-saturation valve assembly (51) for use in a hydraulic system having priority (17) and auxiliary (25) load circuits, the priority circuit providing a priority load signal (19). The anti-saturation valve assembly includes a pressure sensor portion (61) which senses a decrease between pump pressure (23) and the priority load signal (19), and generates a force on a pressure reducing portion (63) to reduce, correspondingly, a pilot pressure (59): The reduced pilot pressure to a pilot valve (35) results in reduced flow to a pilot-operated main control valve (27) in the auxiliary load circuit (25), thus providing anti-saturation protection for the circuit, without throttling a main flow path and wasting substantial hydraulic power.

Abstract: The invention relates to a hydraulic control arrangement for supplying a pressure medium to at least one consumer. The forward line and/or the return line of the consumer comprises a distributing valve that can be continuously controlled and that has two switch positions, and a lowering brake valve that can be placed in an open position due to the pressure in the supply line. The distributing valve is in an open neutral position and can be displaced, electrically or electrohydraulically, from said neutral position into the direction of the second switch position thereof.

Abstract: An actuator control device includes a meter-in solenoid valve (V1) and a meter-out solenoid valve (V2) that control the supply and discharge of a working fluid relative to an anti rod-side oil chamber (4a), a meter-in solenoid valve (V3) and a meter-out solenoid valve (V4) that control the supply and discharge of the working fluid relative to a rod-side oil chamber (4b), a plurality of maps defining characteristics of opening areas of the meter-in solenoid valves (V1, V3) and the meter-out solenoid valves (V2, V4) relative to an actuator speed command, and a controller programmed to determine an operating condition of the actuator on the basis of a detection result from a detector that detects operation information relating to the actuator, and select a map to be used in control from the plurality of maps in accordance with the operating condition of the actuator.

Abstract: In a shifting unit (1) for a vehicle transmission gearbox, the switching unit comprising valves which are connected between with one another by a pressure supply line conduit (58) and by a pressure exhaust line (60) associated with a switch chamber (10) of a switch cylinder (2). The switch chamber (10) of switch cylinder (2) has exhibits at least one opening valve (26) and at least one closing valve (28) through additional valves (62, 64, 66, 68); and the pressure supply line (58) and the pressure exhaust line (60) are separately closed, opened, blocked and/or swapped.

Abstract: A flow control valve includes a pressure compensating valve and a first switching valve. The pressure compensating valve is configured to enlarge an opening area of a variable orifice between a load pressure line and a compensating pressure line when a pressure of working fluid of the compensating pressure line is smaller than a first set pressure, and narrow the opening area of the variable orifice when the pressure of the working fluid of the compensating pressure line is larger than the first set pressure. The first switching valve is configured to switch between a meter-out operation and a neutral operation by an external operation, wherein the working fluid of the compensating pressure line is drained in the meter-out operation, the working fluid of the compensating pressure line is not drained in the neutral operation. The load pressure line guides the working fluid to be supplied to an actuator.

Abstract: A hydraulic system is disclosed. The hydraulic system includes a source of pressurized fluid, a low pressure source, and a plurality of actuators. The hydraulic system also includes a plurality of valves configured to selectively communicate fluid to and from the plurality of actuators. The hydraulic system further includes a first valve disposed downstream of the plurality of valves. The first valve is configured to communicate fluid from the source of pressurized fluid toward the low pressure source.

Abstract: A circuit or system having application for operating an implement or attachment for a power machine is disclosed. The circuit includes a first or primary valve, a second or auxiliary valve connected in series with the first valve and a supplemental line connected in parallel with the second valve to provide fluid to a supplemental system in parallel with the second valve.

Abstract: An anchor structure of a rotation directing valve is used on a housing made from a composite material for pneumatic tools. A valve bushing in the housing is set under a cylinder. The rotation directing valve held by the valve bushing is to control a pneumatic motor in clockwise or counterclockwise rotation by moving it back and forth to alter the flow direction of compressed air. The anchor structure formed on the valve bushing anchors the rotation directing valve while the pneumatic motor rotates clockwise or counterclockwise.

Abstract: The valve arrangement for the activation of a structural element has three inlet switching valves through which a pressure-loaded medium can be conducted. These inlet switching valves are connected on their inflow side to a pressure supply by inflow lines and are arranged parallel to one another in flow terms. Moreover, the valve arrangement has a connection element, which is connected to outflow sides of all the inlet valves by pressure lines. A control line acted upon by the medium is connected to the pressure supply. The three switching-valve groups can be activated by the control line, and in each case two switching valves and in each case one inlet switching valve are assigned to each switching-valve group. A activation valve can be interposed in each case between a switching-valve group and the control line. Three outflow lines for the medium can be arranged between an outflow location for the medium and the connection element.

Abstract: The invention relates to a fluid circuit for load displacement, having a fluid supply line for conveying fluid from a fluid tank by means of a fluid pump to at least one fluid store of a consumer, and having a fluid return line, through which fluid can be returned, driven by the consumer, from the store to the tank, a valve being provided in the fluid supply line which allows a fluid supply flow to pass through from the tank to the store and blocks a fluid return flow from the store to the tank, the fluid circuit also comprising at least one switchable valve which can be switched between a return flow passage position and a return flow blocking position, and being distinguished by the fact that the switchable valve is in that section of the fluid return line which is separate from the fluid supply line.

Abstract: An anti-saturation valve assembly (51) for use in a hydraulic system having priority (17) and auxiliary (25) load circuits, the priority circuit providing a priority load signal (19). The anti-saturation valve assembly includes a pressure sensor portion (61) which senses a decrease between pump pressure (23) and the priority load signal (19), and generates a force on a pressure reducing portion (63) to reduce, correspondingly, a pilot pressure (59): The reduced pilot pressure to a pilot valve (35) results in reduced flow to a pilot-operated main control valve (27) in the auxiliary load circuit (25), thus providing anti-saturation protection for the circuit, without throttling a main flow path and wasting substantial hydraulic power.

Abstract: In a hydraulic driving device for an operating machine, when an output value of an operating device is in a first predetermined range, a pump is stopped and each of an open and closed valve and a hydraulic control valve is closed. When the output value goes beyond the first predetermined range, the pump is started and the open and closed valve is opened. When the output value goes beyond a second range greater than the first predetermined range, the hydraulic control valve is opened to supply a hydraulic fluid to an actuator.

Abstract: A straight traveling hydraulic circuit is provided. In case of performing a combined operation in which a fine operation of a working device and a fine traveling of a traveling device are simultaneously required, the straight traveling hydraulic circuit can allow the working device and the traveling device to operate independently, and thus prevent a declination or sudden traveling of the equipment. In case of performing the combined operation by simultaneously operating the traveling device and the working device, first and second center bypass shifting valves installed on the lowermost stream side of first and second center bypass passages are shifted by a pilot signal pressure that shifts a straight traveling valve installed on an upper stream side of the second center bypass passage, so that the degree of opening of the first and second center bypass passages is reduced to operate the working device and the traveling device independently.

Abstract: The invention concerns a valve arrangement for controlling a hydraulic drive, the supply and the outflow of the hydraulic drive being separately controllable. It is endeavoured to improve the valve arrangement in such a manner that it is intrinsically tight, at the same time having a relatively simple design. For this purpose, a pump pipe and a tank pipe are connected with a first control valve, the first control valve being connected by separate pipes with a second control valve and a third control valve connected in parallel with the second control valve, the second control valve being connected with a first working connection of the hydraulic drive and the third control valve being connected with a second working connection of the hydraulic drive, backflow preventers for preventing the flow from the hydraulic drive in the direction of the tank being connected in parallel with the second control valve and/or the third control valve.

Abstract: The invention concerns a valve arrangement for controlling a hydraulic drive having a first working connection (A) and a second working connection (B), and being connectable with or separable from a pressure source (P), the supply and the outflow of the hydraulic drive being separately controllable. It is endeavoured to improve the energetic efficiency of the valve arrangement. For this purpose, the first working connection (A) is connected with a first control valve and the second working connection (B) is connected with a second control valve, the first and the second control valves being connected with each other and with a third control valve, which is connected with a tank.

Abstract: The present invention relates to a control system and method for a hydraulic working machine characterized by having a construction wherein a flow discharge control valve is disposed in a discharge-side pipe line of a main flow control valve, the amount of operation of an operating lever is converted to a pilot pressure by a remote controlled valve, the pilot pressure is then input to a controller and is calculated into a pressure change speed as operation speed, in a pressure change speed calculator, further, the operation speed is calculated into an electromagnetic valve current in an electromagnetic valve current calculator, then the electromagnetic proportional valve current is output to an electromagnetic proportional valve from a command unit, and the degree of opening of the discharge flow control valve is controlled with a secondary pressure in the electromagnetic proportional valve.

Abstract: A seat valve body mounted in a hydraulic line between a pump line and feeder lines to control hydraulic fluid supplied to variable throttles and to auxiliarily control hydraulic fluid flowing in a load line comprises a first seat valve having a variable control throttle displaced by a difference between a load pressure of the load line and a discharge pressure of the hydraulic pump and varying an opening area from the pump line to the feeder lines based on a displacement amount thereof, a second seat valve having a pilot variable control throttle displacing with respect to the first seat valve, determining a displacement amount of the first seat valve, and varying an opening area based on a displacement amount thereof; and a pilot spool having a pilot variable throttle determining a displacement amount of the pilot variable control throttle of the second seat valve upon switching.

Abstract: The present invention relates to a control system and method for a hydraulic working machine characterized by having a construction wherein a flow discharge control valve is disposed in a discharge-side pipe line of a main flow control valve, the amount of operation of an operating lever is converted to a pilot pressure by a remote controlled valve, the pilot pressure is then input to a controller and is calculated into a pressure change speed as operation speed, in a pressure change speed calculator, further, the operation speed is calculated into an electromagnetic valve current in an electromagnetic valve current calculator, then the electromagnetic proportional valve current is output to an electromagnetic proportional valve from a command unit, and the degree of opening of the discharge flow control valve is controlled with a secondary pressure in the electromagnetic proportional valve.

Abstract: A hydraulic recovery system for a construction machine comprises a recovery valve for supplying at least a part of a hydraulic fluid from a rod-side line, through which the hydraulic fluid is drained from a rod-side hydraulic chamber of an arm hydraulic cylinder, to a bottom-side line through a variable throttle, and a throttle valve for returning the remaining part of the hydraulic fluid, which is not recovered, from the rod-side line to a hydraulic reservoir through a variable throttle. Opening areas of those variable throttles are controlled depending on an arm flow rate supplied from hydraulic pumps to the arm hydraulic cylinder.

Abstract: A hydraulic tool is operable in an open center (OC) and a closed center (CC) mode and includes a cylinder and a piston within the cylinder. The piston defines a drive chamber and a retract chamber. A valve spool selectively supplies and exhausts hydraulic fluid to and from the drive chamber and the retract chamber. An oil tube is coupled to the valve spool and extends through the piston and is in communication with the retract chamber. The oil tube includes at least one hole that can selectively communicate the drive chamber and the retract chamber. A selector sleeve is provided for switching between the OC and CC modes. In the OC mode when the tool is in the neutral mode, the valve spool is configured to supply the hydraulic fluid through the oil tube to the retract chamber such that movement of the piston can allow communication between the retract chamber and the drive chamber through the at least one hole in the oil tube.

Abstract: A hydraulic steering arrangement, having a steering value, which connects a steering motor with a pump, and which has a slide with two front sides, the slide being adjustable by means of a pressure fluid both through a hydraulic steering unit with a steering hand wheel and through an electro hydraulic steering unit with a control pressure generator. The two steering units have working connections and the front sides of the slide are connected with shuttle valves, each of which is connected with hydraulic steering unit on the one side and with the electro hydraulic steering unit on the other side. A valve arrangement connects the working connection of both steering units, which has the highest pressure, with one front side of the slide, and the working connection of both steering units, which has the lowest pressure, with the other front side of the slide.

Abstract: The present invention relates to a hydraulic controller for a working machine, capable of reducing a dead zone of a lever of the working machine and improving the manipulation handling thereof. The hydraulic controller is provided with a back pressure metering valve disposed in a bleed-off line and connecting a bleed-off opening and a tank for adding back pressure to the bleed-off opening; a proportional solenoid control valve for supplying control pressure to the back pressure metering valve; a pilot hydraulic sensor for detecting pilot hydraulic pressure; and a controller for receiving a pilot hydraulic signal from the pilot hydraulic sensor and for outputting a control signal to the proportional solenoid control valve to thereby control the back pressure metering valve.

Abstract: An assembly for reversing a fluid driven motor. The assembly includes a fluid driven motor, and a reversing valve that reverses inlet and exhaust porting to and from the fluid driven motor. An actuation device opens an actuation valve and a fluid supply valve. The actuation valve causes the reversing valve to reverse the inlet and exhaust porting to and from the fluid driven motor when the actuation device opens the actuation valve. The fluid supply valve allows fluid to flow through the fluid supply valve to the motor when the actuation device opens the fluid supply valve. The fluid supply valve also prevents fluid flow through the fluid supply valve to the fluid driven motor when the fluid supply valve is closed.

Abstract: A cut-off valve is mounted so that it can open and close an oil passage which leads a pressure oil discharged from a first pump into a hydraulic oil tank in a neutral state of a spool valve for boom. When an operating lever for boom and an operating lever for arm have simultaneously been operated to a boom raising side and an arm pulling side, respectively, the cut-off valve is closed in proportion to a boom raising or arm pulling pilot pressure. The cut-off valve is controlled using as a parameter a differential pressure between the arm pulling pilot pressure and the boom raising pilot pressure. By doing so, there is obtained a low gain operability in the crane work, while in the parallel pulling work there is obtained an operability of a relatively high gain which matches a quick motion of the arm.

Abstract: A hydraulic-pressure control system for a four-wheel drive vehicle with a hydraulic-pressure operated transfer clutch, which is responsive to a controlled clutch pressure applied thereto to distribute a driving torque passing from a transmission between main drive wheels and auxiliary drive wheels, comprises a pilot-operated directional control valve connected to the transfer clutch for cutting off a supply of hydraulic fluid of the controlled clutch pressure to the transfer clutch and for directing hydraulic fluid of the controlled clutch pressure to the transfer clutch. The system includes a clutch pressure control valve provided upstream of the directional control valve, which pressure control valve is responsive to an external pilot pressure for producing the controlled clutch pressure, and a duty-ratio controlled solenoid valve for decreasingly adjusting the external pilot pressure to be output to the pressure-reduction valve in accordance with an increase in a duty ratio.

Abstract: A fluid-operated brake actuator having a check valve in the spring chamber to equalize the pressure on opposite sides of an operating movable diaphragm. The check valve being double redundant and tamper resistant and comprising a tubular body having a first one-way valve disposed and one end of the tubular body and a second one-way valve disposed at an opposite end of the tubular body. A support plate is mounted to the tubular body to support the second valve and prevents the easy removal of the check valve from the brake actuator.

Abstract: A hydraulic system with a pressure source controllable via a load sensing signal, a pressure sink, at least two working sections, each having a hydraulic consumer and a control valve with a load sensing signal connection and at least one back-pressure valve arranged in a tank pipe between the control valve and the pressure sink. In such a system the pressure required from the pump in the neutral position must be as low as possible. On the other hand, however, oscillations should not occur, when an external force acts on another hydraulic consumer in the neutral position of a control valve. In the neutral position of the control valves the load sensing signal connection is therefore connected with the pressure sink via an auxiliary tank pipe by-passing the back-pressure valve.

Abstract: A pneumatic circuit for use in causing rapid, upward movement of a piston and cylinder device in a glass machine incorporates a supplementary valve which connects an upper part of the cylinder to exhaust for part of the upstroke, and through a restrictor valve to exhaust towards the end of the upstroke.

Abstract: Although a workpiece can be elevated or lowered according to the invention, the workpiece is prevented from rising or falling abruptly. When the workpiece is elevated with an external force, air supplied from the side of an auxiliary air supply chamber pushes down a pressure control piston. Since a difference in pressure between the side of a piston pressure chamber and the side of an auxiliary air supply chamber is small, air is prevented from flushing from the side of the auxiliary air supply chamber into the piston pressure chamber. When the workpiece is lowered with an external force, the pressure control piston is pushed up, thereby increasing the pressure in the piston pressure chamber. At the same time, a relief valve is opened and the piston pressure chamber is exhausted. By the provision of a relief valve, excess air is not exhausted from the piston pressure chamber. The pressure control piston is prevented from rising abruptly, and the workpiece can be gradually raised or lowered.

Abstract: Disclosed is a hydraulic control system of a transfer system for a machine tool, including a hydraulic pump for generating hydraulic pressure, a first directional control valve for controlling the flow direction of fluid from the hydraulic pump, a first flow speed control part located between the first direction control valve and a rotary cylinder to control the flow speed of fluid flowing therebetween, a second direction control valve controlling a flow direction of fluid fed from the first directional control valve and returned to a fluid tank, and a second flow speed control part for controlling flow speed of the returning fluid in accordance with a port variation of the second directional control valve.

Abstract: A fluid operated device has a high pressure fluid cylinder, a low pressure fluid cylinder and a plurality of valves which operate to fluidically connect the two cylinders to provide a compound fluidic device. The device utilizes the exhaust of the high pressure cylinder as input to the low pressure cylinder thereby increasing the amount of work obtained from the pressurized fluid. In the preferred embodiment, the fluid operated device is connected to a compressing cylinder which, through operation of the fluid operated device, increases the fluid pressure of a working fluid. The plurality of valves includes a pair of two-way valves and two quick exhaust valves to increase the cycle speed of the fluid operated device.

Abstract: A hydraulic control valve apparatus including a flow control valve having a pair of variable throttles, a feeder passage, a pair of load passages, directional control valve devices comprise a seat valve having a seat valve body movably disposed in a housing to form an auxiliary variable throttle in the feeder passage, and a control variable throttle (33) formed in the seat valve body for changing an opening area in accordance with an amount of movement of the seat valve body; (b) a pilot line (24, 29-31, 35-37) for communicating a portion (7C) of the feeder passage upstream of the auxiliary variable throttle with a downstream portion (7A, 7B) of the feeder passage through the control variable throttle to determine the amount of movement of the seat valve body in accordance with a flow rate of the hydraulic fluid passing through the pilot line; and (c) pilot flow control (400; 401; 403; 405; 406; 407; 408) having a pilot variable throttle (45) disposed in the pilot line and input (800; 52-59; 159, 54-59; 231A,

Abstract: A fluid operated device has a high pressure fluid cylinder, a low pressure fluid cylinder and a plurality of control valves which operate to fluidically connect the two cylinders to provide a compound fluidic device. The device utilizes the exhaust of the high pressure cylinder as input to the low pressure cylinder thereby increasing the amount of work obtained from the pressurized fluid. In the preferred embodiment, the fluid operated device is connected to a compressing cylinder which, through operation of the fluid operated device, increases the fluid pressure of a working fluid.

Abstract: A connector 5 having an outlet 4 for delivering a pressure oil to a power steering apparatus PS is secured in an opening of a valve receiving bore 2 in which a flow controlling spool valve 3 is received. The connector 5 includes an axial bore 5a which continues from the outlet 4 and in which a valve sleeve 10 is slidably fitted. The valve sleeve 10 has pressure oil passages 11, 12 therein in which orifices 13, 14, 15 are formed, and pressure differentials thereacross are utilized to operate the spool valve 3 in order to return an excess amount of flow. At its outer end, the valve sleeve 10 is formed with a flange 10b, and a restriction 20 is defined between the outer peripheral surface of the flange 10b and the internal peripheral surface of the valve receiving bore 2 for restricting the flow rate of the pressure oil. A pressure differential developed across the restriction 20 is effective to move the valve sleeve 10 to control the orifices 14, 15 so that the latter may be reduced.

Abstract: A switching arrangement for controlling the speed of hydraulic drives, wherein a speed of the drive is assigned to a corresponding flow rate of a hydraulic medium. The flow rate is determined by a preselected pair of phased nozzles placed in the inlet and outlet lines. The nozzle flow rates are selected such that switching between a series of nozzle pairs creates a smoothly changing speed of the hydraulic drive, thus eliminating jolting during starting and braking.

Abstract: A low breakout power transfer unit for transferring power between first and second hydraulic systems includes first and second pump/motor units to allow fluid flow between the first and second pump/motor units and the first and second hydraulic systems, respectively. The transfer unit includes a detection device for sensing fluid flow demand in the hydraulic systems and values for automatically isolating the pump/motor units from the hydraulic systems when the detection means senses substantially no fluid flow demands in a hydraulic system. The transfer unit includes a bypass device for each pump/motor unit for recirculating pumped fluid in excess of fluid flow demand.

Abstract: A regulator valve assembly adapted to be used in conjunction with a torque converter in a vehicular transmission having a pressurized hydraulic distribution system, a cooling system and a torque converter. The regulator valve assembly has a stepped valve chamber to receive a spool valve member for axial translation. The spool valve member defines first, second, third and fourth subchambers within the stepped valve chamber. Axial translation of the valve member effects selective communication between the subchambers. A first land on the spool valve member is interposed between the first and second subchambers. A second land is interposed between the second and third subchambers. A third land is interposed between the third and fourth subchambers, and a fourth land is exposed to the fourth subchamber. A first outlet communicates with the first subchamber. A first inlet and a second outlet communicate with the second subchamber. A second inlet and third outlet communicate with the third subchamber.

Abstract: A control arrangement for regulating the speed of a pressure cylinder increases the controllable flow volume through a proportional-action (control) valve, while avoiding a larger valve or two valves of the same type that must be connected in parallel. A control valve is used which has at least two flow paths connected in parallel. At least one controllable valve is connected in series with a first of the flow paths for the blocking or release of the delivery pipe. The connected first flow path and the controllable valve are connected in parallel to the second flow path.

Abstract: A hydraulic drive system has a consumer of hydraulic power connected to a pressure medium source, e.g., a hydraulic motor 1. The consumer can be actuated by a control valve 4 throttling in intermediate positions; its width of opening is determined by a pressure difference formed at the control valve 4. The pressure difference is derived from a control pressure to be prescribed and the load pressure of the consumer. The consumer can thus be driven with a definite power or a definite torque. To limit the movement speed of the consumer, it is proposed to reduce the control pressure as a function of the speed of movement. The control pressure is present in a control pressure line 7 or 8, which empty at a charging space of the control valve 4, active in the opening direction. A drain line 16 branches from the control pressure line 7 or 8, in which a multiway valve spring-loaded in the closing direction and throttling in intermediate positions is located.

Abstract: A compact and light flow dividing pump is disclosed. The pump includes a housing having an end plate attached to one end thereof. The end plate has a fluid suction port and a pair of fluid discharge ports. A pump mechanism is provided in the housing for receiving fluid through the suction port and discharging the received fluid through the discharge ports. A plurality of discharge passages are formed in the end plate between the pump mechanism and the discharge ports. A control valve is also provided in the end plate to control the flow rate of fluid in the discharge passages.

Abstract: This invention aims at providing a hydraulic circuit apparatus for supplying pressurized fluid into cylinders for a work implement arranged such that during normal operation of the work implement the flow rate of fluid discharged by a pump is controlled such that the difference between the discharge pressure of the pump and the load pressure is always kept constant, whilst during inching operation of the work implement the flow rate of fluid discharged by the pump is reduced.