CYLINDER DEVICE

PURPOSE:To allow two sets of cylinder devices t perform four ways of operations through ON, OFF control of two selector valves, by devising oil hydraulic circuits between both side chambers of a piston in the two sets of cylinder devices and the two selectror valves. CONSTITUTION:For selector valves 30, 34 at OFF (a state as shown) position, pressure fluid is fed to chambers 4A, 4B from a communcation passage 31, while chambers 5A, 5B are released to a low pressure source, and each piston rod 3A, 3B are extensibly moved. Then for the selector valves 30, 34 at ON position, pressure fluid is fed to the chambers 5A, 5B while the chambers 4A, 4B are released to the low pressure source, and each piston rod 3A, 3B is contractibly moved. Further for the selector valve 30 at ON and the selector valve 34 at OFF position, each chamber 4A, 4B and 5A, 5B are released to the low pressure source, and each rod 3A, 3B can be manually moved. Reversely for the selector valve 30 at OFF while the selector valve 34 at ON position, the pressure fluid is fed only to the chambers 4A, 5A, 5B, and only the rod 3A is extensibly moved.