Disclosed is a railway braking system including a control device having a valve with a body having a cavity and a slide having an internal chamber, supply notches and drainage notches each having an overall passage cross-section for a pressure medium having a shape exhibiting an apex, and being movably mounted in the cavity, between a supply position where the supply notch is opposite a supply groove of the body, and a drainage position where the drainage notch is opposite a drainage groove of the body; the device being configured to allow a substantially stable control configuration, wherein the pressure value of the medium is limited, and wherein the slide is positioned in the cavity such that a control notch of the slide is opposite a control groove of the body while the supply and drainage notches are respectively at a distance from the supply and drainage grooves.

A hydraulic control system for blowout preventers systems, frack valves and chokes, and related wellhead and control equipment used in oil and gas well drilling operations. The hydraulic control system can include one or more hydraulic control valves or pressure regulators including an internal, linear slider and pairs of seal rings. Lapped and polished surfaces of the seal rings and sliders can form a dynamic metal-to-metal seal within the hydraulic control valves or pressure regulators.

A hydraulic boosting and regulating system includes an intensifier circuit and a regulator and employs low leak, low crossover valves.

A braking system for a vehicle may include a regulating device disposed between a braking device and a pressure agent source that causes the braking device to move. The regulating device may include a slide having an internal chamber with a supply port, a venting port, and a regulating port opening into the internal chamber and through which a pressure agent from the pressure agent source may flow. The regulating port can be located between the supply port and the venting port. Each of the supply port and the venting port may have a general cross-section for passage of the pressure agent substantially having a shape with at least one apex.

A hydraulic control system for blowout preventers systems, frack valves and chokes, and related wellhead and control equipment used in oil and gas well drilling operations. The hydraulic control system can include one or more hydraulic control valves or pressure regulators including an internal, linear slider and pairs of seal rings. Lapped and polished surfaces of the seal rings and sliders can form a dynamic metal-to-metal seal within the hydraulic control valves or pressure regulators.

A quick coupler circuit includes a cylinder to attach and/or detach an attachment to and/or from a construction machine by expansion and/or contraction, a flow pump to supply fluid to the cylinder, a valve through which fluid for operating the cylinder passes, a spool valve which includes a spool, to move along an axial direction, and to form a pressure at a node of the flow pump according to movement of the spool, an electronic proportional pressure reducing valve to control the spool valve, a switch to perform an ON/OFF operation, and a controller to output a control current to the electronic proportional pressure reducing valve in response to the operation of the switch. The controller is maintains control current which it outputs during the switch's ON operation for a predetermined period of time after the switch's OFF operation.

A track-type loader machine includes a main frame, laterally spaced track roller frames, an equalizer bar pivotally mounted to the main frame and attached to the roller frames, a work implement movably connected to the main frame by a plurality of linkages, and at least one cross-slope actuator which connects one of the roller frames to the main frame. The at least one cross-slope actuator is configured to tilt the work implement and the plurality of linkages in conjunction with the main frame relative to a pivoting axis of the equalizer bar.

A tillage implement has a frame with a center section and first and second outer wing sections hingedly attached to respective outer ends of the center section. Controlling a pressure in a secondary side of a hydraulic circuit enables adjustment of the downward pressure precharge provided by hydraulic cylinders based on a desired stiffness of the implement. Flow from a hydraulic supply through a pressure-reducing valve puts the downward pressure precharge on gauge wheels. Once this desired downward pressure precharge has been achieved, flow from the hydraulic supply is shut off and a check valve holds the pressure such that the hydraulic cylinders hold the gauge wheels in the desired position.

A hydraulic system of a vehicle includes a hydraulic pump with variable delivery capacity. The hydraulic pump is controllable as a function of a load and operatively connected to a drive of the vehicle. The system includes a first brake system for reducing a speed of the vehicle by at least one friction brake, and a permanent brake system being independent of the first brake system and configured to reduce the speed of the vehicle. The permanent brake system includes a first retarder circuit which cooperates with the hydraulic pump such that kinetic energy is removed from the vehicle by the permanent brake system via the hydraulic pump in order to decelerate the vehicle.

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.