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.

An electric-powered fail-safe actuator for use with a valve, where the actuator stores potential energy for conversion to kinetic energy to close or open the valve to the fail-safe position.

In a compressed air supply system for a first compressed air consumer circuit such as an air spring system of a vehicle, a first compressed air line leads to the first compressed air consumer circuit and a distribution line leads to further consumer circuits. A priority valve arrangement is disposed between the first compressed air line, wherein the first compressed air line comprises no safety valve. The first compressed air consumer circuit can therefore be filled at a higher priority, and achieve operational readiness quickly in air spring processes such as lifting or raising activities.

A hydraulic actuator includes an energy recuperation device which harvests the energy generated from the stroking of a shock absorber. The energy recuperation device can function in a passive energy recovery mode for the shock absorber to store recovered energy as fluid pressure or it can be converted to another form of energy such as electrical energy.

There is provided a die cushion device that includes a cushion pad, a hydraulic cylinder configured to lift the cushion pad, and a hydraulic closed circuit connected to a die cushion pressure creation chamber of the hydraulic cylinder. The hydraulic closed circuit includes a pilot drive type logic valve that is operable as a main relief valve at the time of the die cushion operation, and a pilot relief valve configured to create pilot pressure for controlling the logic valve. Hydraulic oil is filled in the hydraulic closed circuit, in a pressurized manner, and the hydraulic oil in the hydraulic closed circuit is pressurized by only die cushion force applied from the cushion pad through the hydraulic cylinder, in one cycle period of the cushion pad.

An injection moulding system, water jet cutting machine or other industrial system has a synthetically controlled variable displacement fluid working machine which outputs hydraulic fluid to one or more fluid consumers, such as rams or hydraulic motors, through hydraulically stiff fluid retaining volumes and receives hydraulic fluid back from one or more fluid consumers through the same or other said hydraulically stiff fluid retaining volumes. Individual piston cylinder assemblies can be allocated to different outputs. There may be no valve between the machine and the consumers. A working chamber of the machine can be caused to undergo a motoring cycle to enable the machine to output more power than is received from a motor driving the machine. An accumulator can be used to provide a source of hydraulic compliance. The machine can be controlled using pressure control, flow control, feed forward control or variable power/variable power limit control.

The construction machine includes: a control valve that switchingly supplies hydraulic fluid from a hydraulic pump to a hydraulic actuator; a control valve drive device that supplies pilot secondary hydraulic fluid to the control valve in accordance with an operation of an operation lever device; a pilot hydraulic pump that supplies pilot primary hydraulic fluid to the control valve drive device; a pressure accumulation device that recovers return hydraulic fluid returned from the hydraulic actuator. The construction machine further includes: a check valve provided in a line between the pilot hydraulic pump and the control valve drive device; a pressure reducing valve that supplied the hydraulic fluid accumulated in the pressure accumulation device; a flow rate reduction device; and a controller that controls the flow rate reduction device in accordance with the pressure in the line between the check valve and the control valve drive device.

A drive train (1) includes an internal combustion engine (2) and working hydraulics (4) having at least one hydraulic pump (7). When operated as a pump, the hydraulic pump (7) sucks hydraulic fluid from a tank (9) and delivers into a delivery line (10) that leads to the working hydraulics (4). When operated as a motor, the hydraulic pump (7) is supplied with hydraulic fluid from a hydraulic accumulator (25). The drive train (1) has a charge pump (20) to supply a charging circuit (23). The charge pump (20), when operated as a pump, sucks hydraulic fluid out of the tank (9) and delivers into a charge pressure line (22) that leads to a charging circuit (23), and the charge pump (20) when operated as a motor is supplied with hydraulic fluid from the hydraulic accumulator (25).

A hydraulic system is disclosed for assisting starting of a machine having an engine. The hydraulic system may include a work tool, a pump driven by the engine to pressurize fluid, and an actuator configured to receive pressurized fluid from the pump and move the work tool. The hydraulic system may also include an accumulator configured to selectively receive pressurized fluid from the pump and from the actuator, an electric starter configured to start the engine, and a motor selectively supplied with fluid from the accumulator to assist the electric starter in starting the engine.

This invention relates to a device for the recuperation of hydraulic energy in a working machine with at least one differential cylinder and to a corresponding working machine.