Abstract: A valve for regulating the flow of fluid through an access port in a fluid chamber includes a body having a first end and a second end, the second end being located in the access port and the first end protruding outside of the access port. An axial bore extends from the first end to the second end, an injection fitting is formed at the first end of the body in fluid communication with the axial bore, and the second end of the body includes a selective sealing interface. The body forms a sealing interface with a threaded inner wall surface of the access port. A one-way valve assembly is positioned within the axial bore, and is arranged to permit a flow of fluid therethrough in a downstream direction and prevent the flow of fluid therethrough in an upstream direction. A bypass passageway extends from the selective sealing interface separate from the axial bore. A connecting passageway connects the bypass passageway with the axial bore upstream of the one-way valve assembly.

Abstract: A valve arrangement includes a spool movable in first and second strokes. A first biasing member has a first spring constant and a first preload, and a second biasing member has a second spring constant lower than the first spring constant and a second preload higher than the first preload. The first biasing member and not the second biasing member biases the spool toward the center position through the entire first stroke and is deflected during movement of the spool from a center position to an intermediate position within the second stroke. The first and second biasing members are deflected during movement of the spool from the intermediate position to an end of the second stroke.

Abstract: A spring loaded track tensioning assembly for a track on a track driven vehicle has a spring subassembly that is retained on a spring shaft under a preload with a first fixed spring retainer and a second slidable spring retainer. The spring shaft has an outer end that extends beyond the second spring retainer and the outer end is slidably received in a bore in a piston or actuator shaft of a grease cylinder, with the end of the actuator shaft bearing on the second spring retainer. The grease cylinder contacts and applies a force to the second spring retainer, for initial positioning of the tensioning assembly, and additional loads on the first spring retainer that compress the spring cause the outer end of the spring shaft to slide in the bore of the actuator shaft as the second spring retainer slides along the spring shaft.

Abstract: A valve for regulating the flow of fluid through an access port in a fluid chamber includes a body having a first end and a second end, the second end being located in the access port and the first end protruding outside of the access port. An axial bore extends from the first end to the second end, an injection fitting is formed at the first end of the body in fluid communication with the axial bore, and the second end of the body includes a selective sealing interface. The body forms a sealing interface with a threaded inner wall surface of the access port. A one-way valve assembly is positioned within the axial bore, and is arranged to permit a flow of fluid therethrough in a downstream direction and prevent the flow of fluid therethrough in an upstream direction. A bypass passageway extends from the selective sealing interface separate from the axial bore. A connecting passageway connects the bypass passageway with the axial bore upstream of the one-way valve assembly.

Abstract: A circuit or system having application for operating an implement or attachment for a power machine is disclosed. The circuit includes a first or primary valve, a second or auxiliary valve connected in series with the first valve and a supplemental line connected in parallel with the second valve to provide fluid to a supplemental system in parallel with the second valve.

Abstract: A pair of pivoting parts are held together with a pin, with a first part, such as a rod end of a hydraulic actuator, positioned between two flanges of a bracket, with the flanges having surfaces mating with sides surfaces of the rod end. A seal is placed in each of a pair of recesses on the opposite side surfaces of the rod end to provide an annular seal around the surface of the pin as the parts pivot, and also having a flange forming a side seal that seats on one of the mating surfaces of the bracket at a location spaced outwardly from the pin and extending annularly around the pin. The seal portion engaging the pin is spaced inwardly from the respective side surface of the bracket, and the outer annular lip seals a space surrounding the pin to form a pocket to receive grease that is used to lubricate the pin relative to the rod end.

Abstract: A valve arrangement includes a spool movable in first and second strokes. A first biasing member has a first spring constant and a first preload, and a second biasing member has a second spring constant lower than the first spring constant and a second preload higher than the first preload. The first biasing member and not the second biasing member biases the spool toward the center position through the entire first stroke and during movement of the spool from a center position to an intermediate position within the second stroke. The first and second biasing members act in series to bias the spool toward the center position during movement of the spool from the intermediate position to an end of the second stroke.

Abstract: A pair of pivoting parts are held together with a pin, with a first part, such as a rod end of a hydraulic actuator, positioned between two flanges of a bracket, with the flanges having surfaces mating with sides surfaces of the rod end. A seal is placed in each of a pair of recesses on the opposite side surfaces of the rod end to provide an annular seal around the surface of the pin as the parts pivot, and also having a flange forming a side seal that seats on one of the mating surfaces of the bracket at a location spaced outwardly from the pin and extending annularly around the pin. The seal portion engaging the pin is spaced inwardly from the respective side surface of the bracket, and the outer annular lip seals a space surrounding the pin to form a pocket to receive grease that is used to lubricate the pin relative to the rod end.

Abstract: A fluid pressure cylinder assembly is provided with a sensor for sensing the extension of a piston rod from a tubular cylinder. The tubular cylinder has a base block that seals the end of the tubular cylinder with an inner wall. The inner wall has a threaded bore for receiving the sensor housing, which has an elongated sensor rod passing into an axial bore in the piston rod. The piston rod carries a sensor element that moves relative to the elongated sensor rod. The inner wall is at an inner end of an access bore in the base block. The sensor is threaded into a bore in the inner wall using a socket that has a slot to permit a sensor lead to extend to the exterior of the socket and out of the access bore so the lead rotates with the socket in the access bore while the sensor is tightened in place. The base block is provided with a slot that extends to the exterior of the base block so that when installed the sensor lead can be extended out through the slot for connection to suitable controls.

Abstract: An extension cylinder is provided and includes an elongated tube having a distal end, a proximal end, and a first fluid opening formed proximate the proximal end. The extension cylinder also includes an elongated rod that is telescopically received within the elongated tube through the distal end thereof. The elongated rod has a second fluid opening formed proximate a rod distal end. A fluid communication tube is disposed between, and enables fluid communication between, the first and second fluid openings. The fluid communication tube includes a length that varies depending on how far the elongated rod is extended or retracted from the distal end of the elongated tube.

Abstract: A control apparatus controls movement of a lift arm and tool on a skid steer loader. Power actuators are coupled to the lift arm circuit and the tool circuit for moving the lift arm and tool along a path. A sensor is coupled to the skid steer loader for sensing a desired parameter and providing a signal indicative of the desired parameter. A power interrupter is coupled between the power actuators for the lift arm and tool and the sensor and interrupts power to the actuators based on the signal. A manually operable bypass mechanism is coupled to the power interrupter and the power actuators and is used to bypass the power interrupter to allow movement of the lift arm.

Abstract: An auxiliary coupler pressure relief hydraulic system for off-road vehicles including a battery, an engine, an engine ignition system, a reservoir of hydraulic fluid, and a pump for providing hydraulic fluid under pressure. Quick couplers couple hydraulic fluid to an attachment mounted to the vehicle. An electro-hydraulic spool valve is connected to a source of pilot pressure and controls the flow of hydraulic fluid to the quick couplers in response to valve actuating signals. Forward and reverse auxiliary control switches are coupled to the spool valve and provide valve actuating signals resulting in fluid flow to the quick couplers in forward and reverse directions. Also included is an ignition switch having RUN, OFF and RELIEF positions.

Abstract: A detent mechanism for a hydraulic control valve, having a detent position in which a detent member is in engagement with a groove and a spring urges the detent member into the groove so that a predetermined force is required to move the detent member out of the groove. A second spring loaded detent member is provided which requires the application of another predetermined force in order to move the mechanism into the detent position. The springs for both of the detent members can be readily changed to adjust the forces required to operate them.