A gangway comprises a fixed platform and a support structure connected to the fixed platform in a manner that allows the support structure to rotate with respect to the fixed platform between a raised stowed position and a lowered deployed position. A self-raising assembly is operative to rotate the support structure from the deployed position to the stowed position. The self-raising assembly includes at least one fluid actuated cylinder connected between the fixed platform and a distal end of the support structure. A raising actuator is usable by an operator to cause operation of the cylinder in a manner that rotates the support structure toward the stowed position.

A piston rod and a rod cover which constitute this hydraulic cylinder are configured from aluminum or an aluminum alloy. An alumite coating film is formed on at least a part of the inner wall surface of the rod cover that constitutes a rod insertion hole, and a diamond-like carbon coating film is formed on the outer wall surface of the piston rod, said diamond-like carbon coating film being in sliding contact with the alumite coating film.

A cylinder device for a hydraulic lifting device has a housing and a piston rod axially movable relative to the housing. A rotary element is mounted on the housing in such a way that a rotary movement of the rotary element relative to the housing is possible and an axial movement of the rotary element relative to the housing is prevented. The piston rod has a movement transmission element, wherein the movement transmission element translates an axial movement of the piston rod into a rotary movement of the rotary element. A sensor unit is attached to the housing, which detects the rotary movement of the rotary element. Furthermore, a hydraulic lifting device with such a cylinder device, a chassis of a mobile device with a lifting device and a mobile device with a chassis are provided.

The various embodiments herein provide a coaxial hydraulic actuator assembly for an aircraft hydraulic system for providing the dual redundancy operations in normal and emergency operations. The embodiments herein adopt a coaxial hydraulic cylinder based actuator system comprising a conventional fixed cylinder with a moving piston actuator. The fixed cylinder with a moving piston actuator is located in a first region. The fixed cylinder with the moving piston actuator is manufactured in tandem with a moving cylinder with fixed piston actuator. The moving cylinder with a fixed piston actuator is located in a second region. The fixed piston actuator in the second region is also referred to as actuation rod. Further, the coaxial hydraulic cylinder based actuator system comprises a first adapter and a first cap for the first region. Similarly, a second adapter and a second cap are provided for the second region.

A hydraulic cylinder enclosing a cavity, the cylinder containing a thru hole, an inner cylinder surface, and a longitudinal axis, and a piston within the cavity and movable relative to the cylinder in parallel to the longitudinal axis between a first and second positions. The piston includes a rod extending through the thru hole, the piston attached to the rod and in sealed engagement with the inner cylinder surface, and dividing the cavity into low and high pressure cavities, and each of the low and high pressure cavities containing a hydraulic fluid. The hydraulic cylinder further including a flexible bladder within the high pressure cavity containing a gas and preventing the gas from mixing with hydraulic fluid in the high pressure cavity. The flexible bladder is attached to an end of the cylinder, and is expandable within the high pressure cavity so that when the piston is in the first position, the flexible bladder and the gas are compressed, and as the piston moves toward the second position, the flexible bladder and the gas fill at least a portion of the high pressure cavity.

A gas cylinder includes supply passages for supplying, to an accommodation chamber, a part of gas supplied to a second port. When the pressure in a first pressure chamber is equal to or lower than a prescribed pressure, a valve element closes a discharge flow passage by the biasing force of a spring member and the pressure in the accommodation chamber. When the pressure in the first pressure chamber exceeds the prescribed pressure, the valve element is moved by the pressure in the first pressure chamber, against the biasing force and the pressure in the accommodation chamber, to thereby open the discharge flow passage.

A tilting pump apparatus includes a pump operation unit arranged between a mudguard, which is configured to obstruct foreign objects entering from a front side, and a tilting pump, which is configured to be rotated for generating hydraulic pressure to transmit movement of the mudguard generated by depressing the mudguard as rotational force for rotating the tilting pump.

The invention relates to a hydraulic cylinder, for example for use with a hydraulic tool, which hydraulic tool is provided with a frame and an element which is movable with respect to the frame by means of the hydraulic cylinder.

A hydraulic tool which is operated by means of a hydraulic cylinder as described above is known from, for example, European patent no. 0641618. This patent discloses a frame which is coupleable to a jib of an excavator or the like and to which an assembly of two jaws can be coupled. One of the jaws is pivotable with respect to the other jaw by means of a hydraulic adjusting cylinder (a double-acting piston/cylinder combination).

The invention relates to a method for producing a piston rod unit, or a shaft, in lightweight construction, with a rod which is hollowly-drilled by means of a deep bore into the rod shank, and the resulting rod opening is closed subsequently by means of a forging process.

A fixed crank driving mechanism is provided, and belongs to the field of a crank driving mechanism, including a servo motor provided at one side of a fixed template, where the servo motor is in transmission connection with a rotating shaft, each end of two ends of the rotating shaft is connected with a crank, a tip end of the crank is movably connected with an elbow-shaped transmission arm, the elbow-shaped transmission arm is movably connected with a piston rod of an oil cylinder through a connecting seat, the connecting seat and the oil cylinder are fixedly provided on a movable template, the movable template is movable along guide posts, and one end of each of the guide posts is vertically and fixedly connected with the fixed template. The fixed crank driving mechanism reduces the weight of the movable template and the load of the servo motor.