A plurality of detection valves (12 and 13) are provided to a housing (1), and at least one air passage (14 and 15), which communicatively connects the detection valves (12 and 13) to each other in series, are provided to the housing (1). One or some of the detection valves (12 and 13) are each configured as a throttle detection valve (13) including a throttle passage (56a).

An actuator includes a housing defining an inlet port, a piston and a return spring disposed within the housing, and an elastically deformable element. The return spring is configured to apply a biasing force to the piston to move the piston to a spring return position. A first fluid pressure applied to the inlet port moves the piston against the biasing force of the return spring to a first actuated position in which the piston indirectly engages a stop portion of the actuator housing. A second fluid pressure, greater than the first fluid pressure, applied to the inlet port moves the piston against the elastically deformable element to compress the elastically deformable element to move the piston to a second actuated position beyond the first actuated position.

Systems and methods for hydraulic droop control of an aircraft wing. One embodiment is a hydraulic droop panel system for an aircraft wing. The hydraulic droop panel system includes a first hydraulic actuator attached to a flap of the aircraft wing, and a second hydraulic actuator attached to a droop panel of the aircraft wing and fluidly coupled with the first hydraulic actuator. The second hydraulic actuator is configured to move the droop panel to a droop position corresponding with movement of the flap and the first hydraulic actuator.

A piston structure body includes: a piston that includes a through hole, an inner circumferential portion, and an outer circumferential portion, the through hole being a hole that is formed to penetrate the piston axially through a center of a first face that is an end face on one end side in an axial direction, the inner circumferential portion defining the through hole and connected to the first face, the outer circumferential portion disposed to surround the inner circumferential portion and connected to the first face; and a piston rod that is inserted through the through hole. A first end face that is an end face of the inner circumferential portion on a back face side of the first face is positioned more closely to the first face than a second end face that is an end face of the outer circumferential portion on the back face side.

A landing gear system for an aircraft includes a retractable landing gear assembly, a hydraulic actuator for actuating movement part, for example a bogie of the landing gear assembly, and an accumulator associated with the actuator. The accumulator comprises a volume of pressurised gas separated from hydraulic fluid by a separator piston. Travel of the separator piston beyond a certain position is indicative of a fault. The accumulator includes a snubbing device that acts to slow movement of the separator piston beyond that position. A monitoring system measures the time taken for the movement of the landing gear part effected by the hydraulic actuator. If the measured time is longer than a threshold time, that is indicative of a possible fault in the accumulator, that might, without the snubbing, remain undetected and/or hidden from view.

The present disclosure discloses a hydraulic machine including a support assembly and a main cylinder device connected with the support assembly. The main cylinder device includes at least two main cylinder assemblies and at least two piston rods respectively. The at least two piston rods are opposite to each other and move along opposite directions and on the same straight line. A support worktable device is disposed on the support assembly and spaced with the main cylinder device. At least two pressing mechanisms are formed between the support worktable device and the at least two main cylinder assemblies or between the support worktable device and the at least two piston rods. The at least two pressing mechanisms are configured for pressing work pieces simultaneously.

A centering apparatus for bi-directionally pivotable hopper doors. The apparatus is coupled between a frame of a hopper car and a bell crank of a hopper door. The apparatus includes a housing with a piston extending from one end. An end of the piston within the housing includes a piston head. A pair of coil springs are disposed within the housing on opposite sides of the piston head and counteract one another to bias the piston head toward the center of the housing and thus bias the hopper door toward a closed state. In a second configuration the apparatus includes a double-acting actuator with a pair of independent piston assemblies. An actuation system coupled to the actuator maintains the actuator and an associated hopper door in a closed position in a normal state and returns the hopper door to the closed position upon a failure in the system.

A pneumatic cylinder with a piston rod movable to fully extended, intermediate and fully retracted positions. The cylinder may have a first head engaging one end of a first tube with a first piston slidably received therein, an intermediate connector engaging the other end of the first tube and one end of a second tube with a second piston slidably received therein, and a second head engaging the other end of the second tube. The piston rod may be attached to the second piston for movement therewith and extend through the intermediate connector, first piston, first tube, and the first head to the exterior thereof.

A hydraulic cylinder (1) which acts as a cylinder hollow rod in an outer hydraulic cylinder (10) is disclosed comprising an inner rod (4) with a piston (2) and piston-gland (3) wherein the cylinder hollow rod (1) is held longitudinally displaceably in the cylinder housing (10). The system additionally has a cylinder base (5) and a fibre cover (14) on the outer casing of hydraulic cylinder (10). The system also has ports for fluid (11, 12 and 13) corresponding to four chambers, (67, 8 and 9 respectively). According to the invention, when pressure is applied to chamber (7), the internal rod (4) extends into the chamber (6), displacing its mass and dramatically increases the pressure in Chamber (6). This displacement is effectively an internal pump which can be activated multiple times within a given stroke of rod (1).

Manual hydraulic override pumps for use with actuators are described herein. An example apparatus includes a manifold including a reservoir port to be fluidly coupled to a reservoir of fluid, a pump port to be fluidly coupled to a pump, a first actuator port to be fluidly coupled to a first chamber of an actuator, and a second actuator port to be fluidly coupled to a second chamber of the actuator. The example apparatus also includes a rotor disposed in a cavity formed in the manifold. The rotor is rotatable between a first actuating position in which the rotor fluidly couples the first actuator port and the pump port, and a second actuating position in which the rotor fluidly couples the second actuator port and the pump port.