초록 ▼

A four-wheel drive wheelchair is disclosed, the wheelchair includes a frame and seat for supporting a user in an upright position and a pair of rear wheels mounted on opposite sides of the frame for supporting the rear end thereof. Front compound-wheels are mounted on opposite sides of the frame for

A four-wheel drive wheelchair is disclosed, the wheelchair includes a frame and seat for supporting a user in an upright position and a pair of rear wheels mounted on opposite sides of the frame for supporting the rear end thereof. Front compound-wheels are mounted on opposite sides of the frame for supporting the front end thereof with each of the wheels capable of rotating in a plane parallel to the side of the frame in a conventional manner and including castor wheels mounted around the perimeter thereof to permit the front end of the wheelchair to roll substantially freely from side to side in addition to forward and backward. Drive for the wheels is provided by sprocket and chain, with the front and rear wheels on each side interconnected to turn in unison and driven by differential control whereby the wheelchair may be steered differentially, by joystick control.

대표청구항 ▼

A four-wheel drive vehicle comprising: a frame; a pair of non-compound rear wheels mounted near the rear end and on opposite sides of said frame for supporting the rear end thereof, each of said rear wheels mounted for rotation in a fixed plane parallel to the side of said frame; a pair of front com

A four-wheel drive vehicle comprising: a frame; a pair of non-compound rear wheels mounted near the rear end and on opposite sides of said frame for supporting the rear end thereof, each of said rear wheels mounted for rotation in a fixed plane parallel to the side of said frame; a pair of front compound wheels mounted near the front end and on opposite sides of said frame for supporting the front end thereof, each of said wheels mounted for rotation in a fixed plane parallel to the side of said frame and providing a substantially continuous traction-providing surface with respect to wheel rotation in said plane and supporting the front end of said vehicle to roll substantially freely transverse to said plane from side to side, the tread of each of said rear wheels providing flotation for each of said rear wheels on outdoor terrain and further wherein the tread of each of said front compound wheels provides flotation which is substantially equal to the flotation of said treads on said front wheels, whereby said front and rear wheels provides substantially the same flotation for said vehicle on outdoor terrain; differential steering means including first means for connecting the front and rear wheels on one side of said frame to turn in unison, second means for connecting the front and rear wheels on the other side of said frame to turn in unison and motorized drive means including one or more electrical motors and control circuits for applying forward or rearward drive power to each set of connected wheels so that said vehicle may be steered differentially, said motorized drive means further including rechargeable batteries for supplying drive power thereto; whereby the front wheels play an active role in the driving, steering and braking of the vehicle, so that powered four-wheel drive and four-wheel differential steering is provided, said front compound wheels permitting the vehicle to be turned with substantially less power than that which is required to turn a skid steer four-wheel drive vehicle.