Abstract: A hydraulic advancement/postponement assembly is operably coupled to a first ejector plate and to a second ejector plate. The hydraulic advancement/postponement assembly includes a first hydraulic cylinder having a first housing defining a first volume and a first piston, the first housing connected to the first ejector plate and the first piston connected to a fixed element. The hydraulic advancement/postponement assembly includes a second hydraulic cylinder disposed in fluid communication with the first hydraulic cylinder, the second hydraulic cylinder having a second housing defining a second volume and a second piston, the second housing connected to the first ejector plate and a second piston connected to the second ejector plate.

Abstract: Braking systems and methods having above atmospheric pressure applied to the working hydraulic fluid of the braking system. In certain preferred arrangements, the braking system includes at least one source of pressure, which pressurizes a fluid. The pressurized fluid acts on respective pressure surfaces of the master plunger(s) and the slave piston(s) that are opposite the active or working surfaces of the master plunger(s) and the slave piston(s).

Abstract: An example aircraft includes (i) a landing gear having a chassis, an axle, and wheels mounted to ends of the axle; (ii) a hydraulic actuator including a cylinder, a first piston coupled to the chassis, and a second piston coupled to the axle; and (iii) a directional control valve including: inlet ports configured to be fluidly coupled to a source of pressurized fluid, tank ports configured to be fluidly coupled to a tank, and workports configured to be fluidly coupled to the hydraulic actuator.

Abstract: A liquid supply device which supplies liquid to a target object, comprises a cylinder having both ends closed; a piston which comparts an inner space of the cylinder into a first space and a second space, and is relatively slidable on an inner wall surface of the cylinder; a piston rod which extends to penetrate an end portion of the cylinder and has a tip end portion connected to the piston; a frame member to which a portion of the piston rod which is located outside the cylinder is fastened; a drive section which causes the cylinder to reciprocate in a direction in which the piston rod extends; a first flow line which is in communication with the first space to flow the liquid therethrough; and a second flow line which is in communication with the second space to flow the liquid therethrough.

Abstract: A positioning system is provided for use in remotely-controlled surgical procedures. Also provided are methods of manufacture and use of such a positioning system. The positioning system may hold an instrument, and may provide multiple degrees of freedom of movement to the instrument. The positioning system may be coupled to a control unit, such that manipulation of the control unit results in movement of the positioning mechanism, thereby eliminating the need to manually hold and position the instrument. According to some aspects, the positioning system may be hydraulically actuated.

Abstract: The invention relates to a hydrostatic drive comprising a first and a second hydraulic pump (11, 12) and a dual-acting hydraulic cylinder (2). The dual-acting hydraulic cylinder (2) comprises a first working chamber (7) and a second working chamber (8). The first working chamber (7) is defined by a first piston surface (4) of a working piston (3) and the second working chamber (8) is defined by a second piston surface (5) of the working piston (3). The first working chamber (7) is connected to a first connection (13) of the first hydraulic pump (11) and a first connection (14) of the second hydraulic pump (12). The second working chamber (8) is connected to a second connection (16) of the second hydraulic pump (12). A second connection (15) of the first hydraulic pump (11) is connected to a hydraulic fluid reservoir.

Abstract: Hydraulic systems are disclosed for operating a press comprising a press ram, a press cylinder including a primary side for activating the press ram and press ram return cylinders for returning the press ram, and at least one flow amplifier comprising a piston including a primary side and a secondary side, the primary side of the piston including a large piston area and a secondary side of the piston having a small piston area, the primary side of the piston being connected to the primary side of the press cylinder and the secondary side of the piston being connected to the press ram return cylinder, at least a portion of the hydraulic system comprising the connection between the primary side of the piston and the primary side of the press cylinder is pressurized.

Abstract: A pair of flexible actuators according to the present invention is supported by a fixture made of a hard rubber at base ends of the flexible actuators. Each flexible actuator includes a movable unit that is capable of bending, a pump unit integrally connected to the movable unit at an end thereof, to control transfer of work fluid sealed in the movable unit, and a pump driver that controls driving of the pump unit. The movable unit includes two long and narrow tubes that each have an accordion wall, a core that maintains the tubes in parallel with each other, and a thin-film-bag-like cover that covers the tubes. The tube, which comes into contact with an object, is made of a soft material. The movable unit that is provided with the tube softly comes into contact with the object at a plurality of plane-contact portions of action of the movable unit, thereby holding the object without scratching the same.

Abstract: A double acting hydraulic system including a master cylinder and a slave cylinder. Each of two slave cylinder spaces has a nipple boring (12, 22), for a nipple valve (40, 50), with an internal section in a form of a seat (16, 26) cooperating with an end (41, 51) of the nipple valve. A sealing section (19, 29) in each nipple boring located outside the seat slidingly and sealingly abuts a sealing section (44, 54) of the respective nipple valve. There is an annular space between each nipple valve and nipple boring, between the seat and the sealing section; and a connecting channel (35) provides communication between the annular spaces. One of the nipple valves has a nipple channel (60) with one opening (61) into the corresponding annular space and a second opening (62) to outside the nipple boring; and a device (63) that cooperates with the nipple channel to prevent fluid flow from outside the nipple boring to the annular space.

Abstract: A fastener installation tool of the push/pull type including an air piston driving a hydraulic piston and further including a head piston driven by the hydraulic piston and coacting with the hydraulic piston to form a closed loop hydraulic circuit. The hydraulic piston is a compound piston including a primary piston and a secondary piston mounted in a blind bore in the upper end of the primary piston. When hydraulic pressures in the closed loop hydraulic circuit exceed a predetermined limit, the secondary piston moves downwardly, against the bias of an internal spring, relative to the primary piston to reduce the overall volume of the compound piston and thereby reduce the pressure in the closed loop hydraulic circuit.

Abstract: The generation of electricity via a steam turbine-driven generator is improved by mixing high-pressure fuel gas with the steam supplied to the turbine. The turbine discharge is separated into gas and steam condensate. The gas is burned to convert the condensate into the steam supplied to the turbine. Maximum benefits of such operation are attained by conducting the combustion of the separated gas with a porous fiber burner to suppress the formation of air pollutants.

Abstract: An electro-hydraulic actuator assembly comprises a master piston-and-cylinder 32, 42 connected to be driven by a rotary actuator 56 and hydraulically connected to a slave master piston-and-cylinder 12 coupled to an output member, e.g. a throttle linkage rod 10, for automatic control of the displacement of the member 10. An override for manual control of the member 10 is provided by a valve 60 which, when opened, hydraulically shortcircuits the member 10 by equalizing pressures on the two sides of the slave piston 16. To re-establish automatic control and synchronize master and slave, a (possibly remote) controller 80 shuts the valve 60 and drives the actuator 56 until master and slave pistons both attain end positions; if necessary, by reopening valve 60 for a short time and continuing to drive the actuator 56.

Abstract: A hydraulic master and slave cylinder assembly of the type in which a piston is positioned in the master cylinder, a piston rod is connected to the piston and extends out of the input end of the master cylinder, a piston is positioned in the slave cylinder, a piston rod is connected to the slave cylinder piston and extends out of the output end of the slave cylinder, a first conduit extends between the output end of the master cylinder and the input end of the slave cylinder, and a second conduit extends between the input end of the master cylinder and the output end of the slave cylinder.

Abstract: The hydraulic brake adjuster (10) intensifying and piston assembly (30) include an exterior pressure device (11) which is disposed separate from a piston (32). The exterior pressure device (11) includes a differential area piston (12) receiving actuation fluid pressure and an outlet (26) which communicates fluid pressure to the piston assembly (30). The piston assembly (30) includes a piston bushing (40) received within the piston (32) to define substantially therebetween a pair of longitudinal pressure chambers (50, 95), a recessed piston (60) received within the piston bushing (40) to define therebetween an axial pressure chamber (70), the axial pressure chamber (70) communicating with one (50) of the pair of longitudinal pressure chambers (50, 95), and the one longitudinal pressure chamber (50) receiving actuation fluid pressure. A piston valve (90) is located within an interior opening (97) in the piston (60), the interior opening (97) communicating with the axial pressure chamber (70).

Abstract: A hydraulic apparatus for remotely controlling the operative mode selector of a motor vehicle automatic transmission. The apparatus comprises a master cylinder having an input member operatively connected to the transmission operative mode selection or shift lever placed at the disposal of the motor vehicle operator, and a slave cylinder mounted on or proximate the transmission casing and having an output member connected to the transmission operative mode selector, the master cylinder and the slave cylinder being placed in fluid communication through flexible conduits such that each displacement of the master cylinder piston as a result of displacement of the master cylinder input member causes a corresponding displacement of the slave cylinder piston coupled to the slave cylinder output member.

Abstract: A technique for pumping an output fluid, especially a particle-laden abrasive liquid. This technique utilizes an output pump and a drive pump which are interconnected through a common chamber containing a drive fluid, specifically water. The output pump includes an output piston within its own pumping chamber for pumping the output liquid by causing the output piston to move through a complete forward stroke. The drive pump includes a drive piston within its own chamber and means for causing the output piston to move the drive piston through its own complete forward stroke. This pressurizes the drive fluid within the common chamber in a way which causes the output piston to move in the forward direction of its stroke. The two pumps are configured such that the forward stroke of the drive piston defines a greater swept volume than the forward stroke of the output piston, thereby to ensure that the output piston will always move through its entire forward stroke before the drive piston.

Abstract: An improved pneumatic-hydraulic actuated single action pull type installation tool for installing pull type fasteners is disclosed which includes a continuously pressurized fluid reservoir operative to maintain a minimum positive pressure on the hydraulic circuit during operation so as to protect the integrity of the hydraulic circuit during normal operating pressure fluctuations and to reduce the possibility of air being drawn into the hydraulic system during sudden pressure drops in the actuating pressure chamber which may occur at the time the pintail portion is separated from the fastener. Further, the reservoir provides a source of make up hydraulic fluid to replace any fluid which may be lost due to leakage. Suitable valves are provided to enable the reservoir to selectively communicate with both driving and return portions of the hydraulic circuit while still enabling selective pressurization thereof.

Abstract: A hydraulic circuit (32), for example, remotely controls a work element (14) and contains first apparatus (34), such as a master cylinder (42), which passes a fluid pressure signal through a fluid pathway (38, 40) in response to an input signal. Second apparatus (36), such as a slave cylinder (44), correspondingly delivers an output signal for controlling the work element (14). Temperature variation can cause fluid volume changes which disrupt synchronized operation of the master and slave cylinders (42, 44). Third apparatus (74) positions the fluid pathways (38, 40) in fluid communication with a tank (28) in the absence of the fluid signal. If the signal passes through one pathway (38, 40), that pathway (38, 40) is automatically blocked from communication with the tank (28). Thus, when the fluid signal is absent from the fluid pathways (38, 40), volume compensation occurs because of dilution of the fluid in the circuit (32) with the tank fluid.

Abstract: Centering and cooling equipment for a hydraulic vibration generator, with a pulsation generator pressurizing a cylinder containing a movable piston, composed of a feed system and a flushing system. The feed system includes spring-loaded non-return valves connecting a fluid reservoir to feed pipes connecting the pulsation generator to the cylinder chambers, and operates to supply cool pressure fluid from the reservoir when pressure in the cylinder chambers falls below a predetermined level. The flushing system includes a control bush/control plunger unit, bush and plunger of which are respectively connected to the piston and cylinder or vice versa, the plunger cooperating with channels in the bush to connect either feed pipe to a return passage according to the off-center position of the plunger in the bush. This system operates to withdraw a quantity of pressure fluid, dependent on pressure and stroke, from the cylinder chambers with each piston stroke.

Abstract: A three-cylinder hydraulic system providing position feedback for controlling powered machinery is described wherein an operator moves a control handle and the various working elements of the machinery respond to follow the path of the control handle, the freedom of movement of which is limited by the ability of the machinery to respond. The system consists of a control station comprised of an assemblage of linkages resembling the machinery to be controlled. Associated with each movable element on both the control station and machine, and with each lever or switch on the machine, are double-acting hydraulic cylinders or rotary actuators. The three cylinders thereby associated with each particular working element and its actuation are connected hydraulically so that the control station cylinder hydraulically manipulates the cylinder that moves the lever or switch that actuates that working element on the machine.

Abstract: Hydraulic input-output device working with a hydraulically unbalanced system. This is made possible according to the present invention by in a useful way taking advantage of the pressures, which arise upon actuation in a hydraulically unbalanced system, in that the created fluid differential can be translated to a fluid flow towards or away from a fluid accumulator.

Abstract: A position-transmitting equipment especially suitable for transmitting steering commands in a small watercraft comprises a transmitter unit in which a cylinder is reciprocable endwise in a housing in accordance with position information to be transmitted. The cylinder is divided internally into two working chambers by a transverse partition. A gland at each end of the cylinder seals about a tubular plunger fixed to the housing so that reciprocation of the cylinder differentially adjusts the working chamber volumes, without risk of jamming and the need for close tolerances. The housing, cylinder and plungers can all be made of plastics material. The plungers provide communication via conduits to a double-acting actuator constituting a receiver unit. The equipment optionally includes a recuperator unit to maintain a selected working fluid pressure in the system.

Abstract: A fluid pressure transducer device including first fluid pressure responsive means and second fluid pressure responsive means which together define a sealed volume of fluid. The first fluid pressure responsive means is exposed to first and second input fluid pressures and responsive to variations in one or both thereof to vary the volume of the sealed volume as a function of the first input fluid pressure modified by the pressure ratio of the second input fluid pressure to the first input fluid pressure. The second fluid pressure responsive means is responsive to the changes in the sealed volume of fluid and produces an output force signal in response thereto. There may be provided a variable volume chamber containing a temperature responsive element vented to the sealed volume of fluid to cause an increase or decrease in the sealed volume to compensate for temperature variations of the sealed volume of fluid.

Abstract: A shutoff valve in a line containing fluid under pressure which after being closed is held closed by another fluid under pressure. The other fluid is one such as air which is available at the valve.

Abstract: A valve mechanism disposed between two pressure sides of a system making it possible for excess pressure device to leave one side of the system to a pressure medium source during a working period of the system. This excess pressure may either be caused by a temperature rise or by a change in the internal volume of the system.

Abstract: A pressure differentially controlled valve for use in a two stage servomotor to prevent reversion from the second stage to the first stage. A first valve initially moves to transfer the output of a servomotor from a first piston to a second piston. A pressure differential responsive second valve prevents the output of the second piston chamber from being communicated to the first piston chamber by moving thereafter with the first valve until an input force is terminated.

Abstract: A closed circuit hydraulic control system for an hydraulic motor including a cylinder, a piston movable in such a cylinder, and a rod connected to one side of the piston, such cylinder having a blind end and a rod end through which the rod extends. A reversible circulating pump having two ports is provided for supplying fluid under pressure to the blind end and to the rod end respectively of the cylinder. A first tubing interconnects the blind end of the cylinder to one port of the reversible pump, whereas a second tubing interconnects the rod end of the cylinder to the other port of the reversible circulating pump. Means are provided to accommodate the volume of fluid displaced by the rod as the piston is moved toward the blind end of the cylinder.

Abstract: A hydraulic clutch system comprising a first piston and cylinder assembly including a piston rod for causing a first piston to move within a first enclosure in response to actuation of a vehicle clutch pedal or the like, a second piston cylinder assembly including a second piston movable within a second enclosure from a non-actuated position to an actuated position to operate a vehicle clutch mechanism, a fluid circuit including a hydraulic conduit communicating fluid from one end of the first enclosure to the second enclosure and operable to bias the second piston from the non-actuated position toward the actuated position, a fluid reservoir communicable with the fluid circuit, and a valve operative in response to preselected movement of one of the pistons within the associated of the enclosures for communicating the reservoir with the conduit.

Abstract: A hydraulic linkagae for transmitting reciprocating motion comprising a master unit, a slave unit, the master and slave units each comprising a pair of interconnected rod pistons reciprocally moveable within the cylinders in opposite directions by a force applied to the pistons, hydraulic lines connecting one master cylinder to one slave cylinder for transmitting motion from master to slave, a reservoir, a pair of one-way pressure valves mounted in opposite directions and in parallel between the reservoir and each master-slave connection so that volumetric increases in the fluid in the system will be forced out through a first valve of each valve pair and to the reservoir, and volumetric decreases in the fluid in the system will draw fluid from the reservoir through a second valve of each valve pair, thereby providing volume change compensation.