PURPOSE: To facilitate each operation of advance, backward motion, driving direction, and braking by providing a lever that operates the control levers of right and left hydraulic pumps simultaneously and a pedal that neutralizes the control levers beside an operating lever that operates the control levers.

CONSTITUTION: Operating levers 4 and 4' are independently connected to the control levers 2 and 2' of right and left hydraulic pumps 1 and 1'. The end of levers 7 and 7' and the median point of 8 and 8' are fixed to the rotary axes 5 and 5' of the levers 4 and 4'. Rods 10 and 10' with long holes that form an isosceles triangle are provided at the levers 8 and 8' and the vertexes of the rods 10 and 10' are connected by means of a pin 25. Then the pin 25 is connected to a pedal 16. Besides, the levers 7 and 7' are connected to spring cylinders 11 and 11' through rods 9 and 9'. The holding levers 13 and 13' of both cylinders 11 and 11' are connected by means of a shaft 15 and an operating lever 18 is connected to the shaft 15. The operating lever 18 can be engaged with the engagement grooves 20a, 20b, and 20c of a fixed inhibiting plate 20.