Abstract: The present invention relates to A device for supplying hydraulic power, the device comprising two hydraulic circuits jointly feeding multi-cylinder hydraulic power transmission means in which each cylinder is connected to a single one of the hydraulic circuits independently of the others. Each hydraulic circuit includes a hydraulic pressure and flow rate generator and a pressure control module controlling said hydraulic pressure and flow rate generator so as to regulate the pressure of said fluid flowing in said hydraulic circuit as a function of said pressure of said fluid flowing in each hydraulic circuit and possibly as a function of one or more parameters external to said device.

Abstract: Embodiments of the disclosure include a redundant control system for a vehicle. The redundant control system includes first and second actuator pistons mechanically coupled to one another and disposed in respective first and second fluid chambers. The first and second actuator pistons are movable by first and second primary stages. One of the primary stages includes a bypass valve with a pilot valve actuatable in response to movement of the first actuator piston.

Abstract: A control valve for a multi-stage hydraulic actuator includes a valve body defining a translation axis, a spool disposed within the valve body and movable along the translation axis, and a flange. The flange is fixed relative to the spool and has an aperture disposed externally of the valve body to removably fix the spool to a spool of a redundant control valve independently connected to the multi-stage hydraulic actuator for mitigating force fights between actuators coupled to the control valve.

Abstract: To provide an actuator device for a flight control surface which can reduce a stress applied to the flight control surface when one of two actuators is operated. The present invention relates to a hydraulically-operated actuator device 30 which drives a flight control surface of an aircraft 1, including a first actuator 31A that is provided with a first piston rod 39A, and drives an aileron body 11; a second actuator 31B that is provided with a second piston rod 39B, and drives the aileron body 11 when the function of the first actuator 31A is lost or reduced; and a single second connection fitting 41 to which the first piston rod 39A and the second piston rod 39B are both connected, wherein the first actuator 31A and the second actuator 31B are connected to the aileron body 11 via the second connection fitting 41.

Abstract: A system for accurately and reliably controlling an electric oil pump includes a control portion adapted to control rotation speed of the motor of the electric oil pump, a regulator valve including a valve body provided with a plurality of ports, a valve spool inserted in the valve body and an elastic member adapted to apply elastic force to the valve spool, and a switch mounted on one side of the valve body including first and second contact points, wherein the control portion increases the rotation speed of the motor when the switch is on and maintains the rotation speed of the motor when the switch is off.

Abstract: A floating piston actuator for use with multiple hydraulic systems includes a housing and a piston assembly. The piston assembly includes an elongate shaft or ram, at least one secured piston coupled to the ram, and a set of moveable pistons moveably disposed within the housing chamber on the ram such that the set of moveable pistons are translatable relative to a longitudinal axis of the ram. The set of moveable pistons form at least three hydraulically separate actuator cylinders where each of the three hydraulically separate actuator cylinders are disposed in fluid communication with a corresponding pressurized fluid source. The floating piston actuator allows hydraulic redundancy while maintaining a similar length compared to existing multi-system actuators. The floating pistons can be arranged in multiple configurations to allow operation with a hydraulic system failure without force fight or binding and with a higher output force than conventional multi-system actuators.

Abstract: A hydraulic actuator includes, but is not limited to a first outflow and a second inflow and outflow as well as a closure device for closing the second inflow and outflow in the direction of outflow. The first outflow an outflowing hydraulic fluid is subjected to flow resistance. When a switching position is reached, the second inflow and outflow is closed in the direction of outflow so that the hydraulic fluid has to be discharged through the first outflow while overcoming the flow resistance. This damps the movement of the hydraulic actuator in the region of an end position.

Abstract: A double redundancy electro hydrostatic actuator system includes two hydraulic pumps; two fail safe valves connected with the two hydraulic pumps, respectively; one dual tandem hydraulic cylinder connected with the two fail safe valves and having a piston rod, wherein the piston rod is moved by switching supply and discharge of the fluid; two switching valves connected with the two fail safe valves; two accumulators connected with the two switching valves and the two hydraulic pumps, respectively; and two chambers connected with the two switching valves, respectively. Each of the two accumulators accumulates the fluid from a corresponding one of the two hydraulic pumps, and sends the fluid to a corresponding one of the two fail safe valves. The two chambers receive the fluid from the two fail safe valves, respectively.

Abstract: A driver is disclosed for powering a pneumatically operated implantable device, such as an artificial heart with a left and a right ventricle. The driver includes a pair of compressors that each has a first and a second compression chamber. In a first mode of operation, both the first and the second compressor power the left and right ventricle of the artificial heart. In the event of a malfunction in the second compressor, the left and right ventricles of the artificial heart may be powered by the first compressor. Similarly, if a malfunction occurs in the first compressor, the artificial heart may be fully powered by the second compressor.

Abstract: A hybrid actuator assembly includes an actuator housing, an electromechanical actuator, and a hydraulic actuator. The electromechanical actuator is disposed at least partially within the actuator housing and is adapted to be controllably energized. The electromechanical actuator is configured, upon being controllably energized, to supply a first drive force. The hydraulic actuator is disposed at least partially within the actuator housing and is adapted to receive pressurized hydraulic fluid. The hydraulic actuator is configured, upon receipt of pressurized hydraulic fluid, to supply a second drive force.

Abstract: The hydraulic apparatus includes: at least a pumping device for pumping a fluid at a first pressure; at least a user device of the fluid at the first pressure; at least an emergency supply device connectable to the user device activating a connection; at least an activation device of the connection that can be operated at a second pressure of the fluid different from the first pressure and interposed between the user device and the emergency supply device, the activation device having an emergency configuration wherein both the pumping device and the emergency supply device are connected to the user device.

Abstract: A wing driving apparatus is made up of a flight controller part for generating a drive signal, first and second servo actuators, a first controller unit having a first drive circuit, and a second controller unit having a second drive circuit. The first controller unit includes a follower signal generator circuit for generating a follower signal. The second servo actuator includes a solenoid valve for invalidating a control to the second serve actuator based on the drive signal from the second drive circuit in response to the follower signal, whereby the second second servo actuator follows the steering wing when the first drive circuit is able to operate the first servo actuator to drive the steering wing.

Abstract: A hydraulic circuit for a hydraulic excavator having a motor drive which acts on at least two closed drive circuits which are connected in parallel, each have a hydraulic pump and a hydraulic motor and which operate on a common output drive, connecting lines being provided between the hydraulic pump and the hydraulic motor of a respective drive circuit, is intended to be improved such that mutual contamination of the components of different driving means with particles in the event of damage is largely avoided and it is also made easier to ascertain the damage. This is achieved by the connecting lines (L11, L12; L21, L22) of each drive circuit (A1, A2) being arranged only between the hydraulic pump (P1, P2) and the hydraulic motor (HM1, HM2) of the respective drive circuit (A1, A2) in such a way that there is no hydraulic connection between the different drive circuits (A1, A2), the respective drive circuit (A1, A2) each having its own control valve (S1, S2) connected to it.

Abstract: A self-centering motor (16) includes a piston (130) which is disposed in a housing (112) and is movable in opposite directions from a centered condition. A pair of centering members (160 and 162) are disposed in the housing (112) to effect movement between the piston (130) and the housing toward the centered condition upon the occurrence of a predetermined condition, such as failure of a pump (44) to supply fluid under pressure. The members (160 and 162) which effect movement of the piston (130) to the centered condition are normally disposed in an overlapping relationship which enables the motor (16) to have a compact construction. In one embodiment of the invention, the members (160 and 162) which effect movement between the piston (130) and the housing (112) toward the centered condition include an inner centering member (162) and a cylindrical outer centering member (160) which extends around the inner centering member.

Abstract: The invention relates to a low-vulnerability device for the operation of a lifting and propulsing helicopter rotor by means of a cyclic plate mechanism, in which the non-rotating plate (5) is coupled at four points (1, 2, 3, 4) to four hydraulic actioning servocontrols each comprising a power jack (9), an anchoring system (10) and a servocontrol-distributor (41, 42), three servocontrols being used when normally working, the fourth being used in back-up in the event of a failure of one of the other three. Each power jack (9) is supplied by an independent hydraulic circuit which comprises the servocontrol-distributor (41, 42) operated by a mechanical input, connected to the cockpit by linkage (13), and a disengageable anchoring system.

Abstract: The present invention provides a kind of pneumatic combined with hydraulic brake chamber, especially relating to a powerful hydraulic brake chamber which is highly stable, ready to provide high-pressure and high-speed actuation and easy to be assembled, dismantled and maintained powerful hydraulic. Said pneumatic type brake chamber is consisted of the following major parts:______________________________________ a cylinder body, a cylinder cover, a central shaft, a shaft sleeve, a piston, a helical spring, a connecting rod, a coupling device, and an alarm device, ect. ______________________________________in which, the pneumatic mechanism is constructed by said cylinder body, cylinder cover, shaft sleeve, piston and helical spring; the hydraulic mechanism is constructed by said central shaft, shaft sleeve, piston and helical spring; and the connecting mechanism is constructed by said connecting rod and the coupling device.

Abstract: A system reduces force fight between hydraulic actuators (22, 24) operated on independent hydraulic circuits (29, 49) which position a control surface (20) of an aircraft. Each circuit includes a hydraulic supply (30, 50). A pressure equalization valve (70) is connected to first sides (42, 62) of the actuators. In the event of a pressure imbalance, a spool (82) shifts in the pressure equalization valve. Movement of the spool enables fluid from the circuit supply to be delivered through the equalization valve to the actuator at the lower pressure, rapidly eliminating the imbalance.

Abstract: A bidirectional flow communication passageway is provided by the present invention in a multiple-circuit fluid pressure responsive system on a motor vehicle to allow a gradual reduction of pressure in a parking brake circuit which is a part of such system. The passageway is restricted to limit such bidirectional flow to a predetermined level. The pressure reduction permitted is sufficient to activate a parking brake valve in such parking brake circuit when a defect occurs in an operating service brake circuit which is also a part of such system.

Abstract: A bidirectional flow communication passageway is provided by the present invention in a multiple-circuit fluid pressure responsive system on a motor vehicle to allow a gradual reduction of pressure in a parking brake circuit which is a part of such system. The passageway is restricted to limit such bidirectional flow to a predetermined level. The pressure reduction permitted is sufficient to activate a parking brake valve in such parking brake circuit when a defect occurs in an operating service brake circuit which is also a part of such system.

Abstract: An emergency supply system for maintaining the emergency flight control of a high-performance aircraft of aerodynamically unstable design having three energy systems, namely, two identical hydraulic systems, connected in parallel for redundancy, for actuation of the control surfaces of the aircraft required for its ability to fly, and an electric on-board system having at least one generator, a rechargeable battery and a non-rechargeable emergency battery, the three energy systems being interconnectible in terms of energy by a power transmission unit, and wherein the two hydraulic systems are divided into subsystems associated with single or several rudder functions which, if necessary, can be disconnected singly.

Abstract: A power assisted steering system and a steering assembly for such a system. The steering assembly has a steering output comprising an arm 6 displaceable through a toothed sector 7 by a racked piston nut 3 drivingly engaging a worm shaft 7 rotatable by a steering input shaft 12. The piston 3 and its cylinder 2 provides a first servomotor for power assisting the steering output. The first servomotor is powered by a first hydraulic system 16 comprising a rotary valve 10 which is responsive to the steering input to control fluid pressure to the first servomotor. The steering system also includes a second hydraulic system 25 comprising an axially responsive spool valve 21 which controls fluid pressure to operate a second servomotor 28 coupled to the steering output arm 6. The rotary and axially responsive valves 10 and 21 are axially coupled together by the shaft 7 which is axially displaceable to control operation of the valve 21.

Abstract: A gas pressure actuator for effecting the reciprocation of the stem of a valve subject to high-pressure loading comprises a tubular housing secured to the valve bonnet and defining a main cylinder chamber connected in axially series relationship with an auxiliary piston chamber which, in turn, communicates with a secondary fluid pressure chamber containing a compressible spring. A rod-like actuator is slidably and sealably mounted within the actuator housing and carries a main piston which cooperates with the main cylinder chamber in sliding and sealable relationship. The auxiliary piston chamber slidably and sealably mounts an auxiliary piston which is movable independently of the main piston. The actuating movement of the main piston produced by the introduction of gas pressure into the main cylinder produces an axial movement of the actuating rod and a compression of the spring. The spring-containing secondary chamber defined by the actuator housing is filled with a virtually non-compressible fluid.

Abstract: A control actuation system for an aircraft including an electromechanically controlled, hydraulically powered actuator for driving a main control valve of a dual hydraulic servo-actuator control system. The actuator includes a tandem piston connected to the main control valve which is controllably positioned by a staged valve of relatively short stroke whereby a force motor of minimum size and energy requirements may be used to directly drive the valve. The staged valve includes a linearly movable valve plunger for simultaneously controlling the differential application of fluid pressure from respective hydraulic systems on opposed pressure surfaces of respective piston sections to cause movement of the piston in response to relatively short axial movement of the valve plunger as long as at least one hydraulic system remains operative.

Abstract: The invention is directed to a multi-motor actuation system for a power drive unit. The system includes three independently hydraulically controlled motors adapted to be drivingly coupled to a power drive unit output. Two of the said motors are normally active at all times and the third motor acts as a back-up motor to provide redundancy for the two normally active motors. A hydraulic failure detection mechanism is controllingly coupled to the three independently hydraulically controlled motors. The hydraulic failure detection mechanism is responsive to any failure of one of the normally active hydraulically controlled motors to thereby cause the third motor to be coupled to the power drive unit. The failure detection mechanism is additionally responsive to a failure of both normally active hydraulically controlled motors to cause the third motor to take over the functions of both of the normally active hydraulically controlled motors.

Abstract: A redundant control actuation system for an aircraft including an electro-mechanically controlled, hydraulically powered actuator for driving a main control valve of a servo-actuator control system. The actuator includes a tandem piston connected to the main control valve and a force motor driven tandem pilot valve axially movable in the piston for simultaneously controlling the differential application of fluid pressure from respective hydraulic systems on opposed pressure surfaces of respective piston sections to cause movement of the piston in response to relative axial movement of the pilot valve as long as at least one hydraulic system remains operative. The piston pressure surfaces are sized and arranged to minimize force unbalance on the piston due to pressure variations in the hydraulic systems. Also, a pilot valve centering spring device may be provided to minimize undesirable transient motions during system turn on and shut down.

Abstract: An electro-mechanical direct drive valve servo system for an aircraft including a drive mechanism that couples the rotary output motion of a rotary force motor to linear motion at a sliding-type valve. The drive mechanism includes a pair of axially spaced rotary members connected to the force motor and a wobble member journaled between and canted by the rotary members with axial thrust bearings interposed between axially aligned opposed planar faces of the rotary and wobble members. A radial output arm on the wobble member is connected to the valve and is constrained for arcuate nutating movement whereby controlled rotation of the rotary member effects nutating movement of the wobble member and output arm which movement effects controlled linear movement of the valve. Additional control inputs such as braking and recentering function inputs are accommodated by the drive mechanism at its input end to take advantage of the mechanism's inherent gearing force ratio.

Abstract: In a pressurized-fluid operated steering gear system for a ship of the kind in which a plurality of actuators (piston-and-cylinder or rotary vane) are disposed in opposed pairs to turn the tiller arm when a diametrically opposed pair is pressurized and the other diametrically opposed pair is relieved of pressure the improvement that there is located in the cylinder, or arcuate chamber, of each actuator a free moving member which separates two distinct pressurized fluid inlets of said cylinder or chamber. If there is no pressure delivery from one inlet the member moves to one end of the cylinder or chamber so that the actuator is worked by pressure solely from the other inlet.

Abstract: Hydraulic apparatus (7), for use where a hydraulic actuator (42) is powered by a first hydraulic supply (40) or selectively and alternatively by a second hydraulic supply (41) independent of the first, which, when a fault occurs, will establish whether the actuator or the first hydraulic supply is at fault, and if it is the first hydraulic supply will isolate that supply and select the second hydraulic supply, but if it is the actuator will ensure that both supplies are isolated. Moreover, the apparatus will establish whether the actuator fault is tolerable and if it is, will select the second supply. By the arrangement described a second hydraulic supply is selected when the first fails, but if the actuator is at fault the second supply will only be selected if that fault is tolerable; if the second supply were to be selected if the actuator was intolerably faulty, failure of the second supply would follow in rapid succession.

Abstract: A hydraulic interlock system is disclosed wherein several pumps may be used to activate a plurality of hydraulic circuits while preventing activation of a single hydraulic circuit by more than one pump simultaneously.

Abstract: A power assisted steering gear assembly having a first fluid system 5 comprising a first pressure operated device such as a double acting piston and cylinder, a first valve for controlling fluid flow to the first pressure operated means in response to a steering input in shaft 2 and a first fluid pump 7. The first pressure operated means can be a conventional power assisted steering gear 1 imparting rotation to a drop arm 8. A second fluid system 20 comprises second valve means controlling fluid flow from a second pump 26 to a second piston and cylinder device incorporated in a ram unit 12. The second valve in the ram unit 12 is responsive to displacement of the drop arm 8 and reacts to determine power assistance provided by the system 20 to a steering maneuver, such power assistance being additional to that provided by the system 5. Displacement of the ram unit 12 controls movement of a steering linkage through drag link 38.

Abstract: A ship's steering gear of the type operated by liquid under pressure incorporates two liquid systems each containing a pump fed from its own supply tank and a thruster unit capable of providing by itself steering action on a steering member. The two systems are interconnected by way of an isolating valve device. Each tank contains a liquid detecting device arranged on a drop of liquid level in that tank first to close the isolating valve device and on further drop of liquid level to stop the pump fed from the tank and start the pump in the other liquid system if it is not operating already.

Abstract: A fluid motor control system (11) assures that automatic changes of motor displacement, which are initiated by occurrence of a predetermined operational condition in the system (11), result in a change of motor speed of the desired magnitude. Flow adjustment elements (76) respond to a displacement increase by reducing the flow of working fluid available to the motor or motors (12, 13) and respond to a motor displacement reduction by increasing the available flow. In one specific form, the system (11) controls a pair of right and left side vehicle drive motors (12, 13) and automatically increases motor displacements while reducing the fluid flow supplied to the motors (12, 13) to reduce travel speed during a turn of travel direction.

Abstract: A circuit for hydrostatically operable devices, especially hydraulic dredges, with at least two working circuits each of which comprises a plurality of hydraulic cylinders and/or hydraulic motors as well as a hydraulic pump while, depending on the requirement, the delivery of the pertaining hydraulic pump is conveyed to each hydraulic cylinder or hydraulic motor and while by means of a plurality of tie lines the deliveries of the remaining hydraulic pumps are selectively conveyed to one of two or more selected hydraulic cylinders or hydraulic motors. The deliveries of the hydraulic pumps flow to the tank after having passed through the control valves associated with the hydraulic cylinders and controlling each of the hydraulic pumps.

Abstract: An improved electrohydraulic servovalve has first and second valve spools mounted for independent sliding movement relative to a body in response to a common command signal. The valve has a first drive mechanism operatively arranged to cause a desired motion of one valve spool in response to the command signal, and has a second drive mechanism operatively arranged to cause a desired simultaneous similar motion of the other valve spool in response to the command signal. The improvement comprises a differential position sensing mechanism arranged to sense the relative positions of the two valve spools and operative to produce an output related to the difference therebetween, and an indicating device supplied with such output and operative to indicate substantially dissimilar relative positions of the spools.

Abstract: A linear fluid actuator having two pistons and two cylinder chambers in tandem to provide redundancy when supplied from independent pressure sources. The actuator is balanced in that the actuator output force is equal in extend or retract positions. The two cylinder chambers are made from separate housings to prevent crack propagation between the chambers and dual piston rod construction is provided to enhance redundancy.

Abstract: A hydraulic control system has two fluid supply circuits which control fluid pressure supplied to respective chambers of a fluid-controlled actuator, each chamber having an individual piston mounted on a common actuator rod. In normal operation, a major part of the pressure is supplied to the actuator by the first circuit in accordance with control signals derived from an external source. The second circuit supplies pressure to its respective chamber at a lower level in accordance with control signals derived from the differential pressure across the piston in that chamber, the pressure supplied by the second circuit acting to reduce the differential pressure across the piston. The system also includes a control unit that responds to malfunction of the first circuit or error in the control signals supplied to the first circuit, by disconnecting the first control circuit from control of the actuator, such as by equalizing pressure across the piston in the first chamber.

Abstract: An improved jam-proof control including a cylinder-piston assembly in which the piston is controllably positioned within the cylinder to perform the control function and in which the piston rod which extends through the cylinder wall is enveloped by a deformable sleeve so that when the piston rod is deformed by sharp impact, the piston rod is permitted to continue to reciprocate within the housing due to the deformation, either due to frangibility or softness, of the piston rod sleeve.

Abstract: A device for controlling hydraulic motors as in an aircraft "fly-by-wire" system wherein redundant hydraulic motors and controls are required to protect against failure of portions of the system or device. The device includes two master valves for controlling flow of fluid to and from the motors, one controlled by electrical signals from a command station and the other controlled mechanically through manual or automatic operation. There is a transfer valve for selecting which of the master valves is to be operable and to provide for smooth transition of control from the electrically controlled valve to the mechanically controlled valve.

Abstract: A hydraulically actuated gate valve having a hermetically sealed piston head adapted to receive a remotely operable actuator for overriding the valve to open the gate.

Abstract: A vehicle brake booster and master cylinder assembly has a vacuum suspended booster section which is controlled by movement of the vehicle brake pedal. A hydraulic booster section is in series with the vacuum suspended booster section, and a master cylinder unit is in series with the hydraulic booster section. The assembly is so interconnected that the master cylinder can be operated manually when there is no or insufficient power pressure to operate either booster section. It may also be operated by actuating the vacuum suspended booster section, and, when no hydraulic pressure is available to the hydraulic booster section, this operation may be followed by manual actuation. It may be operated by initially actuating the hydraulic booster section when there is no vacuum available for initially operating the vacuum suspended booster section, followed by manual actuation as needed.

Abstract: A fluid supply circuit for supplying three motors includes means for sequentially connecting two of the motors to the supply conduit of the third motor as the pressure in the supply conduit rises through first and second threshold levels. The circuit includes a manual override for suppressing the automatic sequential action. The circuit is applied to the control of the booms and bucket of a hydraulic excavator, and provides for semi-automatic digging.

Abstract: A control system for a fluid powered actuator arrangement which includes two drivingly interconnected hydraulic actuator devices, comprises two control valves which are movable in unison to apply operating pressure to the respective devices. The control valves being reponsive to four electro-hydraulic pilot valves, each of which is controlled by four nominally identical electrical input signals. The control system includes means for monitoring the electrical input signals and the operating pressures, and for isolating or rendering inoperative parts of the system in response to several combinations of malfunction indication.

Abstract: A booster having a vacuum powered booster section and a hydraulic powered booster section which are normally actuated together to supply boosted force to a master cylinder. When the air valve of the vacuum booster section is operated to cause atmospheric air to enter the variable pressure chamber of the vacuum booster, it also engages and moves the hydraulic booster control valve to restrict hydraulic fluid flow therethrough, causing the hydraulic booster section control valve to be actuated to create a hydraulic pressure differential across the power wall of the hydraulic booster section. Both booster sections deliver boosted force through the output member of the hydraulic booster section to the master cylinder. Either booster section is operable when for any reason there is no power available for actuation of the other booster section.

Abstract: The self-actuating fluid holding system includes a fluid pump and two fluid valves and two fluid motors all fluid-flow connected together. The valves are arranged to sense the proportionate flow therethrough and to the two motors, and when the flow is out of proportion, such as when one of the connecting lines or a connection breaks to permit the fluid to leak, then the valves have shut off closures which protect the system against fluid leakage.