HYDRAULIC CONTROL CIRCUIT FOR A MASTER CYLINDER WITH MULTIPLE LIMIT POSITION

Abstract of the Invention An hydraulic circuit includes a master cylinder and at least one slave cylinder connected in series circuit. An auxiliary discharge conduit with a solenoid-actuated valve is provided to selectively permit the master cylinder to extend its full useful range after the slave cylinders are fully extended. Under normal operation the valve is closed so that the cylinders may extend together. When the slave cylinders reach full extension, the main control valve is kicked out of its detent and the system locks up in that position. If the operator wants the master cylinder to extend further to a second limit position, he opens the solenoid-actuated valve and again operates the main control valve to extend the master cylinder. The system insures that the main control valve will be released from the detent position when the slave cylinder is fully extended at the first limit position of the master cylinder.