592505 A self-powered person carrier such as a wheelchair is disclosed. The person carrier comprises a vehicle (100) including a chassis, a pair of separately driven front wheels (105, 107), a pair of castor wheels at the rear and a seat for the person. The vehicle includes an internal combustion engine (103) driving at least one controllable hydraulic pump module (110) capable of supplying hydraulic oil in either direction to two reversible hydraulic motors (105A, 107A) each directly driving one of the two front wheels. The at least one controllable hydraulic pump module (110) has a first control shaft or pintle for controlling the amount and direction of hydraulic fluid supplied to the first reversible hydraulic motor and having a second control shaft or pintle for controlling the amount and direction of hydraulic fluid supplied to the second hydraulic motor. Forward or backward components of movement of a single pivotally mounted control knob (116) are translated by a translation mechanism (117) into equal movements of the control shafts and side to side components of movement of the knob (116) are translated into differing movements of the control shafts so that the vehicle may be steered. Embodiments with both mechanical and electrical translation mechanisms (117) are disclosed.
