Drive pump arrangement for working vehicle

Claim 1

A working vehicle having two pumps P1, P2 for driving hydraulic motors M1, M2 provided for opposite running devices 1, 1 respectively, a valve mechanism for bringing the vehicle into a low-speed state wherein a fluid is supplied from the pumps P1, P2 to the motors M1, M2 respectively or alternatively into a high-speed state wherein the combined fluid from the pumps P1, P2 is supplied to the motors M1, M2 in series, valves V2, V4 for reversibly rotating and stopping the motors M1, M2 respectively, and manual operating means 17, 17 provided for the valves V2, V4 respectively, the working vehicle comprising an operating assembly 15 provided for the valve mechanism and including a power supply circuit C for an electric operating unit 16 or 16a for bringing the valve mechanism into the high-speed state when energized, a manual switch S1, a safety switch S2 provided with a driven cam 18, the switches S1, S2 being connected in series with the power supply circuit C, the safety switch S2 being attached to one of the manual operating means 17, 17, and a cam-type operating member 19 provided for the driven cam 18 and attached to the other operating means 17, the safety switch S2 being closed when both the operating means 17, 17 are in a specific position relative to each other for running the vehicle straight, the safety switch S2 being opened when the operating means 17, 17 are brought out of the specific relative position to run the vehicle in a turning state.