Four-wheel drive wheelchair with compound wheels

• US 4,926,952 A
• Filed: 03/30/1989
• Issued: 05/22/1990
• Est. Priority Date: 05/01/1984
• Status: Expired due to Fees

• Current Assignee: Jeffrey Farnam
• Original Assignee: Jeffrey Farnam
• Inventors: Farnam, Jeffrey
• Primary Examiner(s): Nilson, Robert G.
• Application Number:
  US07/331,596
• Time in Patent Office: 418 Days
• Field of Search: 180/6.5, 180/7.1, 180/251, 180/907, 280/211, 280/242 WC, 301/5 R, 301/5 P
• US Class Current: 180/6.5
• CPC Class Codes: A61G 2203/14 Joysticks
• CPC Class Codes: A61G 5/046 at least three driven wheels
• CPC Class Codes: A61G 5/06 with obstacle mounting facilities, e.g. for climbing stairs, kerbs or steps
• CPC Class Codes: A61G 5/10 Parts, details or accessories
• CPC Class Codes: A61G 5/1051 Arrangements for steering
• CPC Class Codes: B60B 19/003 Multidirectional wheels
• CPC Class Codes: B60B 2380/12 Ball bearings
• CPC Class Codes: B60Y 2200/84 Wheelchairs
• CPC Class Codes: Y10S 180/907 Motorized wheelchairs

Abstract

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.

Claims

1. 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.

2. A vehicle comprising:

a frame;

a pair of rear wheels, said rear wheels being fixed to rotate relative to a rear portion of said frame in first and second parallel planes;

a pair of front wheels, said front wheels being fixed to rotate relative to a front portion of said frame in third and fourth parallel planes which are substantially parallel to the first and second planes; and

a plurality of compound wheel members mounted for rotation in at least two rows about a peripheral edge of each of said front wheels, with a space defined between said rows, said compound wheel members being oriented so as to allow rolling movement of said respective front wheel in a direction which is substantially transverse to the planes, whereby the vehicle may be steered with a minimum of resistance, and whereby a smooth support surface is provided for engaging an underlying support surface.

3. 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 to 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 provide flotation which is substantially equal to the flotation of said treads on said rear wheels, whereby said front and rear wheels provide 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 motors and controls for applying forward or rearward drive power to each set of connected wheels so that said vehicle may be steered differentially;

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.

4. A vehicle comprising:

a frame;

a pair of rear wheels, said rear wheels being fixed to rotate relative to a rear portion of said frame in first and second parallel planes;

a pair of front wheels, said front wheels being fixed to rotate relative to a front portion of said frame in third and fourth parallel planes which are substantially parallel to the first and second planes; and

a plurality of compound wheel members mounted for rotation about a peripheral edge of each of said front wheels and oriented so as to allow rolling movement of said respective front wheel in a direction which is substantially transverse to the planes, whereby the vehicle may be steered with a minimum of resistance, wherein the tread of each of said rear wheels provides 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 rear wheels, whereby said front and rear wheels provide substantially the same flotation for said vehicle on outdoor terrain.

5. A four-wheel drive vehicle comprising:

a frame;

a pair of non-compound first end wheels mounted near a first end and on opposite sides of said frame for supporting the first end thereof, each of said first end wheels mounted for rotation in a fixed plane relative to the side of said frame;

a pair of second end compound wheels mounted near the second end and on opposite sides of said frame for supporting the second end thereof, each of said wheels mounted for rotation and a fixed plane relative to the edge of said frame and providing a substantially continuous traction providing surface with respect to wheel rotation in said plane and supporting the second end of said vehicle to roll substantially freely transverse to said plane from side to side, the tread of each of said first end wheels providing flotation for each of said second end wheels on outdoor terrain and further wherein the tread of each of said second end compound wheels provides flotation which is substantially equal to the flotation of said treads on said first end wheels, whereby said second end and first end wheels provides substantially the same flotation for said vehicle on outdoor terrain;

differential steering means including first means for connecting the second end and first end wheels on one side of said frame to turn in unison, second means for connecting the second end and first end wheels on the other side of said frame to turn in unison and motorized drive means including one or more motors and controls for applying forward or rearward drive power to each set of connected wheels so that said vehicle may be steered differentially;

whereby the second end 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 second end 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.