Abstract: An apparatus controls the movement of a ripper for a machine. Tilt and lift cylinders controllably actuate the ripper. Hydraulic control valves control the flow of hydraulic fluid to the respective cylinder. An auto-return button produces an auto-return signal in response to being depressed by the machine operator. A controller receives the auto-return signal and delivers a ripper control signal to the hydraulic control valves to automatically raise the ripper to a predetermined position.

Abstract: A blade control system includes a directional control valve, a fluid regeneration valve and a selector valve for selectively controlling fluid flow between a pump and first and second hydraulic cylinders and between the cylinders. With the valves positioned at preselected operative positions, pressurized fluid from the pump is directed to the head end chamber of the first cylinder, fluid expelled from the rod end chamber of the first cylinder is diverted to the head end chamber of the second cylinder, and fluid expelled from the rod end chamber of the second cylinder is combined with the fluid being directed to the head end chamber of the first cylinders to provide two stages of fluid regeneration for increasing the extension speed of the cylinder.