PURPOSE: To perform steering operation by using two oil-pressure pumps by connecting the inlet port of one running switch valve connected in tandem with the first oil-pressure pump to the inlet port of the other running switch valve connected with the second oil-pressure pump.
CONSTITUTION: The direction switching valve 27 of a left-side running motor 5 is connected to the most downstream of the center bypass of the first oil- pressure pump P1, and the direction switching valve 23 of a right-side running motor 7 is connected in tandem to the second oil-pressure pump P2. A valve 41 is provided in the downstream of the center bypass 40 of the oil-pressure pump P2, and the upstream sides of the direction switching valves 23 and 27 of both the running motors are led to each other by a connecting pipe 30 with a switch valve 47. By this, during the running operation and the operation of various working actuators at the same time, the oil-pressure pump P1 and P2 can be mutually led to each other without interruption with the running of the body.
TAMURA SEIJI
HIRATA TOUICHI
| JPS5227128A | 1977-03-01 | |||
| JPS5175229A | 1976-06-29 |