The present disclosure relates to a hydraulic circuit for a forklift, and more particularly, to a hydraulic circuit for a forklift which is capable of preventing an engine from being stopped due to surge pressure that instantaneously occurs when a lift cylinder reaches an end stroke and thus cannot be operated any further when the lift cylinder is extended. According to the hydraulic circuit for a forklift according to the exemplary embodiment of the present disclosure, which is configured as described above, the accumulator is provided on the hydraulic line through which the working fluid is provided to the lift cylinder, and as a result, the accumulator may quickly absorb surge pressure when the surge pressure is produced in the lift cylinder or the hydraulic line.

A pneumatic control device includes a functional assembly that has an interruption valve device for the selective opening or interruption of at least one main working channel used for the pneumatic control of a pneumatic actuator. The functional assembly also contains a manually actuatable valve device that is connected to the interruption valve device by means of at least one auxiliary working channel and which enables manual pneumatic control of the connected actuator, if the at least one main working channel is interrupted by the interruption valve device at the same time. A process control device can also be equipped with a control device of this type.

A hydraulic actuator circuit is disclosed for use with first and second shock absorbers, which each may include a piston disposed within a housing. The piston helps define upper and lower working chambers. The circuit may have a motor, a first pump, driven by the motor, and is associated with the first shock absorber and the motor. A second pump, driven by the motor, may be associated with the second shock absorber. A first accumulator communicates with both of the first and second pumps. A first switch valve may assist in controlling fluid flow into the chambers of the first shock absorber. A second switch valve may assist in controlling fluid flow into the chambers of the second shock absorber.

The linear actuator comprises a double-chamber solenoid pump comprising at least one pump coil, a multi-way valve and at least one pump armature that can be moved by energizing the at least one pump coil and is provided with a switching armature by means of which the multi-way valve can be switched and which can be moved by energizing the at least one pump coil. In the method, both the switching armature and the pump armature are moved by energizing the pump coil.

In a fluid circuit for an air cylinder connected to a switching valve provided with exhaust ports, a head-side pressure chamber is connected to the switching valve by a first pipe, and a rod-side pressure chamber is connected to the switching valve by a second pipe. A first restrictor is disposed at a connection point between the first pipe and the switching valve or in the vicinity of a first output port of the switching valve, and a second restrictor is disposed at a connection point between the second pipe and the switching valve or in the vicinity of a second output port of the switching valve.

A hydrodynamic compression tool comprises an electrical motor, which can be powered by a control circuit, a hydraulic pump which can be actuated by the motor so as to increase the pressure of a hydraulic liquid acting on an actuating piston, two jaws, which can be mutually moved by the actuating piston between an open position and a closed position for carrying out the compression or the cut, an actuating button, which acts on a switch of the control circuit to actuate the motor, a return device which returns the jaws to the open position by a return of the hydraulic fluid from the actuating piston towards the hydraulic pump through a return valve, and a mechanism for delaying the opening of the return valve via the return device, so as to allow verification of the position of the jaws before the return of the jaws to the open position.

A header assembly for an agricultural harvesting machine comprises a first frame assembly, a second frame assembly that supports a cutter, and is movable relative to the first frame assembly, a float cylinder coupled between the first frame assembly and the second frame assembly, an accumulator, a controllable reservoir, and fluidic circuitry. The fluidic circuitry comprises a first conduit forming a first fluid path that provides a flow of pressurized fluid under pressure to the float cylinder, so the float cylinder exerts a float force on the second frame assembly, a valve mechanism that is actuatable to inhibit fluid flow along the first fluid path between the accumulator and the float cylinder, a second conduit forming a second fluid path fluidically coupled to the controllable reservoir, the controllable reservoir being controllable to add fluid to the float cylinder.

To provide a drift-prevention valve device, a blade device, and a working machine capable of operating an actuated unit and preventing the machine body from drifting with a simple configuration. The drift-prevention valve device is provided with a non-return valve 41 that allows the flow of hydraulic oil from a control valve 28 to a head chamber 34h of a blade cylinder 34 and blocks the flow of the hydraulic oil in the reverse direction; and a piston accommodation part 42 separately disposed from an accommodation part 70 of the non-return valve 41, configured to movably accommodate a power piston 43. The power piston 43 defines a first piston chamber 42p1 communicating with a rod chamber of 34r of the blade cylinder 34 and a second piston chamber 42p2 for drain positioned on a poppet 71 side of the non-return valve 41 and communicating with a tank 52. The power piston 43 is connected to the poppet 71 of the non-return valve 41, so that the power piston 43 can be operated by the difference between the urging force of the poppet 71 by a spring 72 of the non-return valve 41 and a rod chamber pressure of the blade cylinder 34.

A hydraulic system including a first cylinder conduit configured to couple to a cylinder, an auxiliary conduit configured to couple to a case drain conduit, and a pressure regulator coupled to the first cylinder conduit and to the auxiliary conduit. The pressure regulator may block fluid flow to the auxiliary conduit if a first fluid pressure is less than or equal to a threshold pressure and enable fluid flow if the first fluid pressure is greater than the threshold pressure. The hydraulic system further includes a supplemental conduit with a check valve that directs fluid from the auxiliary conduit to a reservoir. The check valve blocks fluid flow if a second fluid pressure is less than or equal to a third fluid pressure, and enables fluid flow if the second fluid pressure greater than the third fluid pressure.

The present invention pertains to a split ring assembly for adjusting the throughput of a fluid of a hydraulic valve comprising an elastomeric element being adapted to mount a split ring around a hydraulic ram, wherein the elastomeric element is arranged around the outward circumference of the split ring, wherein the throughput of the fluid is adjustable depending on the degree to which the throughput of hydraulic fluid is limited by the split ring.