Methods of modifying a GM Powerglide low range servo assembly for high line pressure applications as well as replacement components for Powerglide low range servo assemblies and replacement low range servo assemblies.

This disclosure includes hydraulic apparatuses and methods for redundant actuation of a hydraulic device. Some apparatuses include a hydraulic device having a first hydraulic actuator and a second hydraulic actuator, wherein each of the first and second hydraulic actuators comprises at least a first hydraulic cavity, a second hydraulic cavity, and a piston. Some apparatuses also include a controller coupled to the hydraulic device. In some embodiments, the controller is configured to receive hydraulic fluid from a fluid source via at least two parallel hydraulic lines coupled to the controller, select a first hydraulic line of the at least two parallel hydraulic lines, and transfer the hydraulic fluid from the selected first hydraulic line to a first cavity of the first hydraulic actuator to apply pressure to a first piston to actuate the hydraulic device.

This disclosure includes hydraulic apparatuses and methods for redundant actuation of a hydraulic device. Some apparatuses include a hydraulic device having a first hydraulic actuator and a second hydraulic actuator, wherein each of the first and second hydraulic actuators comprises at least a first hydraulic cavity, a second hydraulic cavity, and a piston. Some apparatuses also include a controller coupled to the hydraulic device. In some embodiments, the controller is configured to receive hydraulic fluid from a fluid source via at least two parallel hydraulic lines coupled to the controller, select a first hydraulic line of the at least two parallel hydraulic lines, and transfer the hydraulic fluid from the selected first hydraulic line to a first cavity of the first hydraulic actuator to apply pressure to a first piston to actuate the hydraulic device.

The present invention regards a fluid actuator arrangement comprising a first and second cylinder of a cylinder arrangement, a piston rod arrangement, a first and second piston device associated with the piston rod arrangement, wherein respective first and second piston device divides respective first and second cylinder into a first and second chamber provided for connection to a valve device of a fluid supply device. The first piston device comprises a piston rod engagement and disengagement device, which is adapted to engage or disengage the first piston device to/from the piston rod arrangement. The invention can be put into use for aircraft, such as commercial aircraft designed for long distance flights, for construction industry, jacking systems for oil well drilling and service platforms, agricultural equipment industry, marine industry, crane manufacture industry, and others.

The invention relates to a hydraulic drive (1) comprising a working cylinder (2) and a travel cylinder (3) which is mechanically connected to the working cylinder (2). The working cylinder (2) and the travel cylinder (3) each comprise an upper and a lower cylinder chamber (21, 22, 31, 32), and all four cylinder chambers (21, 22, 31, 32) of the working and travel cylinder (2, 3) are connected to one another in a suitable manner in a closed pressure circuit (4) which is filled and prestressed with a hydraulic fluid (F). A rotational speed-variable hydraulic machine (5) with a first and second pressure connection (51, 52) is arranged in the pressure circuit (4) in order to conduct the hydraulic fluid (F) between the individual cylinder chambers (21, 22, 31, 32) of the working and travel cylinder (2, 3) during the operation (B) of the hydraulic drive (1). At least one first and second distributing valve (6, 7) are arranged in the pressure circuit (4) such that the respective valve switch positions (61, 62, 71, 72, 73) which are suitable for the different operating phases of the hydraulic drive (1) together with the suitably driven hydraulic machine (5) allow a common movement of the work and travel cylinder (2, 3) in one or the other piston movement direction (R1, R2). For this purpose, preferably only the first and the second distributing valve (6, 7) are arranged in the pressure circuit (4). The hydraulic drive (1) requires a minimum number of components, maintains a low installation complexity, improves the energy efficiency, can be constructed in a compact manner, and can be operated in a sufficiently variable manner.

A triple piston fluid pressure cylinder is disclosed with a parallel arrangement of the pistons that allows a combination of the first two stages of the cylinder into one stage so that the first two stages of the cylinder are working into the same common space.

As the result of that arrangement the overall length of the triple pistons cylinder is reduced by a significant amount.

The saved length may be used to increase the stroke of the cylinder.

The piston body assembly is built around the piston arrangement, and is composed of a cylinder tube with one head end cover and one rod end cover and one middle fixed pistons.

The middle fixed piston is extended through an extension tube to an extension fixed piston.

The invention relates to a crane comprising a base for attaching the crane to a harvester or similar work machine, a main boom having two ends, one end pivoted to the base, an articulated boom having two ends, one end pivoted to the said main boom , an actuator cylinder for moving the main boom relative to the base having a cylinder part, a second actuator cylinder for moving the articulated boom relative to the main boom, a pressure cylinder in connection with one actuator cylinder, arranged to follow this actuator cylinder in order to produce pressure for the second actuator cylinder, wherein the pressure cylinder is arranged to form an essentially coaxial multi-chamber cylinder with the actuator cylinder to be followed.

An apparatus for actuating a valve includes a first actuator having a first actuator housing and second actuator with a second actuator housing. A first plate is positioned within the first actuator housing and a second plate is positioned within the second actuator housing. An intermediate stem extends from a first pressure chamber of the first actuator housing to the second plate. A pressure media path extends through the intermediate stem and a second seal nut that extends into the second plate, the pressure media path providing fluid communication between the first pressure chamber, and a second pressure chamber of the second actuator housing. An injection port is open into one of the first pressure chamber and the second pressure chamber. The first plate and the second plate are movable in response to pressure media injected into the injection port, for actuating the valve.