The present disclosure provides a pneumatically drivable actuator for setting a position of a valve closure element in a valve, comprising a piston, which is moveable in a pressure chamber by influence of a drive gas, and a locking mechanism for mechanically locking the piston relative to the pressure chamber. The actuator further comprises a ventilation device for venting the drive gas from the pressure chamber while the piston is mechanically locked relative to the pressure chamber, such that pressurization of the pressure chamber is prevented. A method of locking a valve closure element relative to a valve body of a valve that is controllable by a pneumatically driven actuator is also disclosed.

An apparatus includes a drive mechanism, a first cylinder comprising a first piston coupled to the drive mechanism, and a second cylinder comprising a second piston. The first cylinder includes a first fluid reservoir and a second fluid reservoir, with the first piston disposed between the first fluid reservoir and the second fluid reservoir. The second cylinder includes a third fluid reservoir and a fourth fluid reservoir, with the second piston disposed between the third fluid reservoir and the fourth fluid reservoir. The apparatus further includes a first fluid line coupling the first fluid reservoir to the fourth fluid reservoir, and a second fluid line coupling the second fluid reservoir to the third fluid reservoir. The first piston comprises a threaded portion disposed in a threaded aperture of the first cylinder.

A cylinder device includes: a first piston (8) inserted in a first cylinder hole (4) so as to be movable in an axial direction, a piston rod (7) being hermetically inserted in the first piston (8), the first piston (8) being fixed to the piston rod (7); a second piston (10, 37) inserted in a second cylinder hole (5) so as to be movable in the axial direction, the piston rod (7) being inserted in the second piston (10, 37); and a partition wall (13) dividing a cylinder hole (6) into the first cylinder hole (4) and the second cylinder hole (5), the partition wall (13) being movable in the axial direction.

Disclosure herein are hydraulic systems and method of use thereof. The hydraulic systems can include a hydraulic cylinder and a manifold. The hydraulic cylinder can have a first end and a second end. The hydraulic cylinder can include a first port, a second port, and a third port. The first port can be located proximate the first end. The second port cane be located proximate the second end. The third port can be located in between the first port and the second port. The manifold can include a first valve and a second valve. The first valve can be in fluid communication with the first port and the third port. The second valve can be in fluid communication with the second port and the third port.

A vented pressurized gas-powered actuator includes a housing having a central longitudinal axis and an inner surface. The inner surface has a constant radius between first and second planes extending perpendicular to the axis. At least one vent groove extends from the inner surface in a direction away from the axis. The at least one groove has a first end intersecting the first plane.

Examples described here include a device that has a housing defining a cavity, and a force sensor. The device also includes a first hydraulic actuator positioned in the cavity, and a second hydraulic actuator positioned in the cavity. The first and second hydraulic actuators move between respectively relaxing modes and thrusting modes along respective longitudinal axes. The longitudinal axis of the first hydraulic actuator is substantially parallel to the longitudinal axis of the second hydraulic actuator. The device also includes a first actuated member coupled to the first hydraulic actuator, and a second actuated member coupled to the second hydraulic actuator.

A hydraulic system including a first cylinder conduit configured to couple to a cylinder, a second cylinder conduit configured to fluidly coupled to the cylinder, and a bypass conduit fluidly coupled both to the first cylinder conduit upstream of the cylinder and to the second cylinder conduit downstream of the cylinder. The bypass conduit is configured to enable intermittent fluid flow of a hydraulic fluid from the first cylinder conduit to the second cylinder conduit while bypassing at least a portion of the cylinder.

The hydraulic actuator comprises: a hydraulic input cylinder having an input piston; a hydraulic output cylinder, which is hydraulically coupled to the input cylinder; and a pressure-limiting valve, which limits the output cylinder with respect to pressure in dependence on the usability of a force on the input piston. The method is a method for operating such a hydraulic actuator, wherein the drive actuator is deflected with deflections having a deflection duration at a deflection frequency for the duration of an acting or a non-acting phase of the hydraulic actuator, wherein the deflection duration defines a movement stiffness of the hydraulic actuator and the deflection frequency defines the resulting deflection speed of the hydraulic actuator.

A method for selectively coupling or uncoupling a coupling with a release, arranged between the supply conduit and a cylinder, on the basis of pressure in a supply conduit. The method includes providing an operating pressure prevailing in the supply conduit in order to provide hydraulic liquid to the cylinder on the basis thereof, and providing an uncoupling pressure prevailing in the supply conduit for the purpose of activating shut-off valves in the supply conduit and on the cylinder, and activating a release which uncouples the coupling. A coupling for respectively coupling and uncoupling a supply conduit which is connected to the coupling to/from a cylinder, as well as to an assembly including a pump, a cylinder, a supply conduit between the pump and the cylinder, and such a coupling.

An object is to provide a cylinder device which can be used successfully over a long period of time. The cylinder device includes a cylinder, a piston, an external cylinder, a tank and first piping. The piston is slidably inserted into the cylinder. The piston divides an interior of the cylinder into a rod-side chamber and a piston-side chamber. The external cylinder is disposed outside the cylinder and covers the cylinder. The tank is formed in a space between the cylinder and the external cylinder and stores an operating fluid. The first piping constitutes part of a first passage through which passes the operating fluid supplied to and discharged from the rod-side chamber or the piston-side chamber. The first piping has two ends one of which has a larger outer diameter than the other end. The first piping is disposed in the tank.