Patent ID: 7025157

Claim:
A material handling vehicle, comprising: a drive system controlled by the operator to drive the material handling vehicle in a selected direction; a steering mechanism coupled to the drive system and controlled by the operator to select a direction of motion, the steering mechanism being moveable along an arc between a substantially horizontal position and a substantially vertical position; a brake coupled to the drive system to prevent motion of the material handling vehicle; an angular position indicator activated by the steering mechanism as the steering mechanism is moved along said arc and providing a control signal comprising at least two bits, the control signal indicating an angle of movement of the steering mechanism; and a controller for receiving the control signal and for selectively placing the material handling vehicle in one of a plurality of successive driving states based on the angle of movement of the steering mechanism, and wherein the controller verifies that a transition between successive driving states is a valid transition based on the previous driving state of the material handling vehicle as the steering mechanism is moved, and applies the brake if the transition is not a valid transition.