A pneumatic chamber 20 is configured to include a first pneumatic chamber 21 pressurizing a first piston 11 and a second pneumatic chamber 22 pressurizing a second piston 12. The first pneumatic chamber 21 communicates with the second pneumatic chamber 22. The hydraulic pressure generating unit 55 is internally provided with a hydraulic chamber 30, and the hydraulic chamber 30 is configured to have a first hydraulic chamber 31 pressurized by the first pneumatic chamber 21 via the first piston 11 and a second hydraulic chamber 32 pressurized by the second pneumatic chamber 22 via the second piston 12. The hydraulic pressure generating unit 55 is movable in a thrust direction in a cylinder 2, and the second hydraulic chamber 32 has a function of fixing the moving hydraulic pressure generating unit 55 in the cylinder 2 by causing a thin portion 15 to be elastically deformed in a radial direction due to hydraulic pressure. The first hydraulic chamber 31 outputs hydraulic pressure of the first hydraulic chamber 31, which is increased by the fixing, to an output rod 7.

An actuator device includes two drive units for an actuator output element. The first drive unit has a first piston chamber and a first piston displaceable therein and also first hydraulic means for displacing the piston. The second drive unit has a second piston chamber and a second piston displaceable therein and also second hydraulic or pneumatic means for displacing the piston. The second piston is joined to the actuator output element for conjoint movement therewith and can be coupled to the first piston for thrust, so that the second piston is displaceable in an outward direction by the first piston. The first drive unit is configured for a larger thrust force than the second drive unit, while the second drive unit is designed for a greater stroke speed than the first drive unit.

A coupling e.g. for an actuator, comprises a housing which is preferably in the form of a ring mounted around the end of the outer rod and which can be mounted to a component e.g. a cowl being deployed. Within the housing of the coupling is provided a ring disk. This is sized and arranged within the housing such that there is some clearance between the ring disk and the housing so as to permit some eccentric movement.

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 servo-control. The servo-control comprises at least one body as well as a power shaft and a control piston arranged in each body, the at least one body and the power shaft respectively forming two power members. One of the power members bears at least on end-stop member and the power member without an end-stop member bears a passivation actuator. The passivation actuator comprises a passivation shaft which bears an end-stop and a passivation piston, the passivation piston being arranged to be mobile in longitudinal translation in an enclosure, an elastic system being arranged between the passivation piston and the enclosure.

A hydraulic actuator including a barrel, a plunger piston, and a loose piston. The plunger piston is arranged inside the barrel and at a first axial end thereof includes a piston end element. The loose piston is arranged within the barrel, thereby partitioning the interior of the barrel into a first compartment and a second compartment. The piston end element partitions the interior of the barrel into a second and a third compartment. The hydraulic actuator includes a first opening for providing a hydraulic pressure into the first compartment, and a second opening for providing a hydraulic pressure into the second compartment or into the third compartment. The hydraulic actuator is configured such that the second compartment is in fluid connection with the third compartment.

A hydraulic cylinder may include a cylindrical body, a first piston rod coupled with a first end of the body, and a second piston rod coupled with a second end of the body. The first piston rod may include a cavity with an inner diameter, and the second piston rod may have an outer diameter that is smaller than the inner diameter of the cavity. The hydraulic cylinder is adjustable from a closed position, in which a length of the first piston rod is housed inside the body and a length of the second piston rod is housed inside the cavity of the first piston rod, to an extended position, in which the first piston rod extends through the first end of the body and the second piston rod extends through the second end of the body.

A hydraulic lifting column comprising a base structure, a head structure and a lifting structure. The lifting structure comprising a hydraulic power unit and hydraulic linear actuators extending between the base structure and the head structure, the hydraulic power unit acting on the hydraulic linear actuators. The lifting structure comprising four linear actuator units with a mutually parallel, vertically oriented working direction. Each linear actuator unit comprising a double cylinder having two-cylinder bores arranged next to one another and two piston structures with piston rods oriented parallel to one another and extendable in opposite directions from the double cylinder. The four lower piston rods are connected to the base structure at the corners of a first quadrilateral and the four upper piston rods are connected to the head structure at the corners of a second quadrilateral.

Disclosed is a liquid chromatography solvent pump including a motor, a first piston, a second piston, and a variable output drive system coupling the motor to at least one of the first piston and the second piston. The variable output drive system includes a gearbox configured to provide a non-equal ratio between an input from the motor and an output delivered to at least one of the first piston and the second piston. The first piston and the second piston are configured to deliver a flow of solvent in a liquid chromatography system.

A liquid chromatography solvent pump includes at least one motor, a first piston, a second piston, and a continuously variable output drive system coupling the at least one motor to at least one of the first and second pistons. The first piston and the second piston are configured to deliver a flow of solvent in a liquid chromatography system.