Abstract: A construction machine including a pump, a pressure sensor measuring a pressure, and a work cylinder including a rod operable to extend and retract. The work cylinder has a bore chamber, a rod chamber, a bore chamber pressure sensor, a bore pressure, a rod chamber pressure sensor, and a rod pressure. The machine includes an input moveable between neutral, extension, and retraction positions, and a sensor to measure the position. The machine includes a controller programmed with an algorithm to control movement of the work cylinder on the basis of the detected position of the operator input. The algorithm is configured to confirm that the pump pressure exceeds the bore side chamber pressure as a prerequisite to setting a command that controls movement of the work cylinder for rod extension, in response to identification of the operator input in the rod extension position.

Abstract: A construction machine including a variable displacement pump, and a boom cylinder including a rod operable to extend and retract to move a boom of the construction machine. A first chamber of the boom cylinder is configured to be supplied with fluid from the pump during rod extension while fluid is removed from a second chamber of the boom cylinder. The second chamber of the boom cylinder is configured to be supplied with fluid from the pump during rod retraction while fluid is removed from the first chamber of the boom cylinder. The construction machine has an active ride control mode in which a valve between the boom cylinder and the pump remains open, and the pump is configured to actively damp pressure fluctuations in the boom cylinder by variation of a displacement setting.

Abstract: 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.

Abstract: 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.