A new means of achieving a valve float position in a closed centered hydraulic control valve. The valve has a main spool position whereby pressure compensator load sense control pressure is drained to tank through the main spool. Secondly, a pin acts on the pressure compensator to prevent the main pump flow from reaching the main section spool. Finally, the new spool position adds a connection from the consumer to tank, enabling a float position.

A work machine includes a mechanical arm and a hydraulic actuator coupled to the mechanical arm to move the arm between a first position and a second position. A valve is in fluid communication with the hydraulic actuator for supplying fluid to the hydraulic actuator. A pump is configured to discharge fluid to the valve. An engine is operatively connected to the pump. A coolant system is in thermal communication with the engine and includes a temperature sensor. A controller is in communication with the pump and the temperature sensor. The controller is configured to transmit a control signal to the pump to modify a flowrate of the pump and to adjust the flowrate of the pump in response to a signal from the temperature sensor that a temperature is at or above a set temperature value.

A compensator device includes a hydraulic cylinder with a first end, a second end and an inner cylinder rod extending axially from the second end; and a piston rod with a piston movable axially within the cylinder. The inner cylinder rod has an end with a blocking diameter. The piston rod is generally hollow and includes a cavity to receive the blocking diameter of the inner cylinder rod.

A braking system including a brake actuator, a control valve, a control assembly, and at least one pressure sensor. The control valve is disposed to direct hydraulic fluid to the brake actuator at a rate corresponding to a magnitude of a control signal. The control assembly includes a mixed-mode control system. The at least one pressure sensor is configured to measure a pressure of the hydraulic fluid to the brake actuator. The control assembly is configured to determine a position of the brake actuator. The mixed-mode control system is configured to determine a position command and a pressure command. The mixed-mode control system is configured to adjust the magnitude of the control signal based on at least one of the position command and the pressure command so as to reposition the brake actuator from a first position to a second position.

A single stage flapper type servovalve comprises a valve housing comprising a bore, a pair of opposed nozzles arranged in the bore and a flapper element arranged between the pair of nozzles. The valve housing further comprises a plurality of fluid ports for communicating a working fluid to and from the nozzles and in fluid communication with the housing bore. The valve housing and the nozzles are both made from a stainless steel material.

In a spinning machine or winder comprising at least one pneumatic device (7) including a supply line (8) for a first pressure (P.sub.1), a regulating line (9) for an operating pressure (P.sub.2), a valve system (10), a manometer (13), and a data processing unit (14), the regulating line (9) is connected to the manometer (13) in such a way that the operating pressure (P.sub.2) is measured by the manometer (13). The valve system (10) comprises a first valve (11), which is connected to the supply line (8), or a first path (17) of a directional control valve (16) for feeding a pressure medium into the regulating line (9), and a second valve (12), which is connected to a surrounding atmosphere, or a second path (18) of a directional control valve (16) for draining the pressure medium from the regulating line (9), wherein the data processing unit (14), which is connected to the manometer (13) and to the valve system (10), is designed for opening the first valve (11) or the first path (17) and closing the second valve (12) or the second path (18) if the operating pressure (P.sub.2) is less than a first set value, and opening the second valve (12) or the second path (18) and closing the first valve (11) or the first path (17) if the operating pressure (P.sub.2) is greater than the first set value or a second set value, wherein the first pressure (P.sub.1) is greater than the operating pressure (P.sub.2).

Provided is a safety valve (10) comprising a body (12) which defines an incoming fluid passage (14) and a return fluid passage (20). The incoming fluid passage (14) generally enables a fluid to pass from a fluid reservoir (18) through the body (12) to the tool head (16). The return fluid passage (20) generally enables a fluid to return from the tool head (16) through the body back to the fluid reservoir (18). The body (12) further comprises a diverter (22) which is displaceable between an active position and an inactive position. When the diverter (22) is in the active position, the diverter (22) redirects the fluid via a shunting passage (24) from the incoming fluid passage (14) to the return passage (20) to prevent operation of the tool head (16). Conversely, when the diverter is in the inactive position, fluid is allowed to pass freely through the incoming and return passages (14) and (20), respectively, to allow operation of the tool head (16).

A new means of achieving a valve float position in a closed centered hydraulic control valve. The valve has a main spool position whereby pressure compensator load sense control pressure is drained to tank through the main spool. Secondly, a pin acts on the pressure compensator to prevent the main pump flow from reaching the main section spool. Finally, the new spool position adds a connection from the consumer to tank, enabling a float position.

A valve system for use with a cylinder having an extensible rod, includes first and second valve assemblies, each including an inlet/outlet port configured to selectively be coupled with a source of pressurized gas, a check valve biased toward a closed state and having a check valve body at least partially receivable within a first port of the cylinder, a flow control valve positioned in series between the inlet/outlet port and the check valve, and an inlet pilot port connected with the check valve for opening the check valve when supplied with pressurized gas. First and second pilot lines extend to the respective inlet pilot ports from respective outlet pilot ports of the opposite ones of the first and second valve assemblies. When pressurized gas is supplied to the inlet/outlet port of a valve assembly, pressurized gas is also supplied to the opposite inlet pilot port.

The invention provides a hydraulic circuit for feeding an actuator (1) comprising first and second chambers (5, 6), the circuit comprising a slide valve (10) with a slide (16) that is movable between first and second extreme positions (18, 19) on either side of a stable central position (17) so that: in the central position, it connects the chambers (5, 6) of the actuator to a return port; in the first extreme position (18), it connects the first chamber (5) to a feed port and the second chamber to the return port; and in the second extreme position (19), it connects at least the second chamber (6) to the feed port.

According to the invention, the hydraulic circuit includes pressure-maintaining means (20) for maintaining pressure in the first chamber of the actuator while the slide is passing through the central position on being moved from the first extreme position to the second extreme position.