Abstract: A portable hydraulic power unit includes a frame, a fluid tank supported by the frame, and a manifold supported by the frame. The fluid tank is configured to store a supply of hydraulic fluid for powering a hydraulically-driven tool. A reciprocating pump is mounted on the exterior of the fluid tank and on the exterior of the manifold. The reciprocating pump is secured to the fluid tank and the manifold with fasteners extending through a cylinder body of the reciprocating pump.

Abstract: Provided is a slewing-type working machine capable of reducing back pressure generated during slewing.

Abstract: The Remotely Controlled Vehicle Pedal Actuator is a pneumatically powered tool for use in the motor vehicle repair and maintenance industry that enables a mechanic to solely, remotely, and repetitively depress and retract a vehicle accelerator, clutch or brake pedal. The device comprises a pneumatic linear actuator (commonly termed an air cylinder) that is pneumatically connected to a foot, hand or electronically activated pneumatic valve and a pneumatic power source. One end of the actuator is attached to a vehicle steering wheel with the opposite end attached to the vehicle accelerator, clutch or brake pedal. Activating the pneumatic valve pressurizes the actuator causing the actuator rod arm to extend and depress the vehicle pedal. Deactivating the pneumatic valve depressurizes the actuator causing the actuator rod arm to withdraw and retract the vehicle pedal.

Abstract: A drive control system of a crawler vehicle has a lever, a hydraulic distributor for feeding pressurized oil over a feed line to a hydraulic actuator. The hydraulic actuator can engage and release a central clutch. A cable has a first end fixed to a rod of the hydraulic actuator, and a second end connected to the hydraulic distributor. The cable activates and deactivates the hydraulic distributor, depending on the position of the rod. A main pulley is integral with the lever about which the cable is wound.

Abstract: To improve the separation efficiency of a gas-liquid separator in the gas-liquid separator and an air conditioner, the gas-liquid separator having a vessel with an inlet pipe and an outlet pipe is arranged such that an exit end section of the inlet pipe is formed to be closed or to have a gap, an expanded end section having a width greater than the diameter of that portion of the inlet pipe which crosses a container of the gas-liquid separator is provided, and that a lateral hole is formed in a side face of the expanded end section. Refrigerant vapor and refrigerant liquid are efficiently separated from each other at the expanded end section, and this improves separation efficiency of the gas-liquid separator.

Abstract: Provided is an apparatus provided in a working machine to lower a load, comprising a hydraulic pump, a hydraulic actuator, a manipulation device having a manipulation member, a meter-in flow control device, a meter-out flow control device, a back pressure valve, a regeneration fluid passage branched from the meter-out fluid passage at a position upstream of the back pressure valve and merged with the meter-in fluid passage, and a check valve. The meter-in flow control device controls a meter-in flow rate in a region of the meter-in fluid passage upstream of a merging point with the regeneration fluid passage. The meter-out flow control device controls a meter-out flow rate in a region of the meter-out fluid passage upstream of a branching point of the regeneration fluid passage so as to make the meter-out flow rate be greater than the meter-in flow rate.

Abstract: A hydraulic system includes an actuator, a pump, rod side and cap side fluid connections between the pump and the rod and cap side chambers, respectively, at least one selectively actuatable regeneration valve that selectively provides flow from the cap side fluid connection to the rod side fluid connection, and a controller. The controller controls the pump to selectively vary the flow rate of the pump in response to a commanded motion to control movement of the piston. The controller actuates the regeneration valve during a retraction of the piston into the cylinder when pump is acting as a motor.

Abstract: A hydro-mechanical transmission for an agriculture vehicle, such as a tractor. The transmission includes an input shaft, a hydrostatic unit driven by the input shaft, a mechanical transmission driven by the hydrostatic unit and/or the input shaft, and a valve assembly having a pressure control valve assembly to control an output speed of the hydrostatic unit. A mechanical shift control valve assembly is coupled with the mechanical transmission to selectively engage one of the gear sets of the mechanical transmission and adjust the hydrostatic unit speed.

Abstract: A heavy-construction machine (1) including a working implement (5) having one or a number of arms (6) articulated with regard to the chassis (2) of the machine. An assembly consisting of at least one hydraulic cylinder (7) that causes the working implement (5) to move relative to the chassis (2) is provided together with a hydraulic circuit that supplies these cylinders based on the control commands issued by a hydraulic manipulator. The machine is capable of operating according to two distinct modes of which one is a lifting mode and the other is a loading mode. In each mode, cylinder travel can be freed when the manipulator is in a predetermined position corresponding to a position referred to as floating control. The machine further includes a mechanism for rendering the floating control position of the manipulator inactive when the machine is operating in lifting mode.

Abstract: A hydraulic control device includes a first oil path; a second oil path; a third oil path; an engagement pressure generation unit; a signal pressure generation unit; and an internal pressure switching unit that switches between a non-reduced pressure state where locking occurs due to the signal pressure inputted and a source pressure is outputted unchanged as internal pressure to the first oil path, and a reduced pressure state where the signal pressure is not inputted and a hydraulic pressure is regulated to a constant pressure from the source pressure, based on a feedback pressure of the internal pressure and an urging force of a first urging unit, and outputted as the internal pressure to the first oil path.

Abstract: A power plant produces power by using high pressure gas to push a piston. The power plant uses a supply device to provide the high pressure gas to a cylinder and controls an admission valve and an exhaust valve to admit and exhaust the high pressure gas for pushing the piston and rotating a crank member to produce power.

Abstract: A hydraulic control device of construction machine is provided with a control valve lying between a hydraulic pump and a hydraulic actuator for opening and closing a meter-in control flow path, and a flow rate control valve lying between a pump discharge line on the upstream side of the above control valve and a tank. The above flow rate control valve receives a pump pressure and a load sensing pressure corresponding to a pressure on the downstream side of the meter-in control flow path as a pilot pressure, and is activated for opening and closing so as to maintain a constant differential pressure therebetween. The above flow rate control valve is maintained in a closed state by a pilot pressure switching valve when the load sensing pressure is low. The above control valve opens a bypass line when the meter-in control flow path is closed.

Abstract: A valve assembly for load pressure-independent control of consumers is disclosed, which includes a main valve having a directional element and a metering throttle part. The valve assembly includes a shut-off valve for leakage-free shutting off of a work line leading to the consumer. This shut-off valve is designed with a pilot valve whereby a pressure chamber of the shut-off valve acting in the closing direction may be relieved towards a tank or a low-pressure source. The pilot valve is, in accordance with the invention, controlled open by a main slide of the main valve.

Abstract: A quick coupler for coupling an implement to a work machine is provided with a control system that substantially prevents inadvertent and unintended release of the implement from the machine. Inadvertent and unintended release of the implement is prevented by requiring two separate switches to be actuated to release the implement. Actuation of one switch supplies pressurized fluid to a fluid circuit connected to an actuator operable to release the implement from the machine. However, the pressurized fluid supplied in response to actuation of the one switch is not sufficient to activate the actuator. Concurrent actuation of a second switch raises the pressure of the fluid supplied to the actuator fluid circuit to a level sufficient to activate the actuator, thus releasing the implement.

Abstract: An hydraulic control arrangement which is chiefly used for a mobile working machine, especially for a wheel loader, and has at least one hydraulic cylinder with the aid of which a working tool can be moved, a directional control valve for controlling the pressure-fluid channels between the hydraulic cylinder, a pressure-fluid source and a tank, a hydraulic accumulator which can be connected to the pressure-fluid source via a filling line, and a control valve with the aid of which a connection between the hydraulic accumulator and the hydraulic cylinder can be controlled to open and close. The aim of such a hydraulic control arrangement is to avoid undesired movements of the hydraulic cylinder. This is achieved wherein the fact that the hydraulic accumulator can be filled up only when the directional control valve is actuated.

Abstract: A tree-harvester operating system for controlling in particular the tree-feeder motors (5), the crosscut saw (6) and the cylinder (18) operating the function of the feeder and the limbing blades, especially in grapple processors. A simple operating system has been achieved by taking advantage of a two-direction feeding of pressurized oil by means of two delivery lines (2) and (3). By preventing the rotation of the tree-feeder motors (5) and by allowing at this time only one flow direction of pressurized oil to the crosscut saw, it has thus been possible to utilized the pressurized oil drive opposite to this flow direction of the saw (6) separately for the cylinder (18) which operates the function of the feeder and the limbing blades, the direction of movement of the cylinder (18) depending on the position of valve (15).

Abstract: A hydrostatic transmission control system including a variable displacement pump driving a constant displacement motor arranged in a hydraulic circuit having a controlled by-pass valve interconnected for positioning the pump swash plate in two established positions corresponding respectively to a stand still position or a full speed position of the motor. A thermosensitive element is coupled to the valve control spool for bypassing the flow of the pump in the event of motor jamming.

Abstract: The operation of a 4-way, open-center, three position hydraulic valve is coordinated with the operation of the pump for the hydraulic system in which the valve is controlling flow. As the valve is moving from its open-center position to either one of its other two operative positions, a switch maintains the power circuit for the pump open and closes that circuit to activate the pump after the valve has assumed one of the other two positions.

Abstract: The invention relates to an assisted hydraulic control, especially for steering all types of vehicles, and comprising a double-acting receiver or hydraulic cylinder, the piston of which forms two chambers in the cylinder, the piston rod extending into one of the chambers only and having no counter-rod extending into the other chamber. The first chamber thus has a smaller effective section than the second chamber, and the resulting asymmetry of operation of the piston and therefore of the steering is compensated by an arrangement in which the distributor valve means of the control, which couples a return conduit to the second of two actuating conduits in a first working position, isolates the return conduit and connects together the second of two pilot conduits, the second actuating conduit and the first actuating conduit in the second working position.