Powered wheelchair

• US 7,562,728 B1
• Filed: 10/12/2006
• Issued: 07/21/2009
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: Allan Alfred Voigt
• Original Assignee: Allan Alfred Voigt
• Inventors: Voigt, Allan Alfred
• Primary Examiner(s): Ellis; Christopher P
• Assistant Examiner(s): SWENSON, BRIAN L
• Application Number:
  US11/580,333
• Time in Patent Office: 1,013 Days
• Field of Search: 180/22, 180/24.01, 180/65.1, 180/907, 180/908
• US Class Current: 180/65.1
• CPC Class Codes: A61G 5/045 Rear wheel drive
• 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: Y10S 180/907 Motorized wheelchairs

Abstract

An apparatus for urging a person of limited physical ability from a first location to a second location includes a self-propelled type of wheelchair that has two driven wheels disposed under the chair. A pair of preferably front-disposed castors is included. Together, the pair of castors and the two driven wheels define a first plane that the wheelchair is disposed on when the wheelchair is on a level surface. A pair of additional driven wheels is provided that are elevated with respect to the first plane. The additional driven wheels can be disposed either in front of or behind the two driven wheels. Together, the two driven wheels and the pair of additional driven wheels define a second plane. When the wheelchair is disposed along a sufficient incline, it tilts from the first plane into the second plane. At that time, contact with the surface is made by the pair of additional driven wheels, whereby the pair of additional driven wheels provides an additional motive force to help propel the wheelchair.

Claims

1. An improvement to a powered wheelchair that includes at least three wheels and wherein two of said three wheels are driven wheels, and wherein a third of said at least three wheels is free spinning and wherein a bottom of said at least three wheels define a first plane, and wherein said bottom of said at least three wheels of said powered wheelchair are disposed on said first plane when said wheelchair is disposed on a generally planar and level surface, the improvement comprising:

including two additional driven wheels with said wheelchair in addition to said two driven wheels, and wherein said two additional driven wheels are disposed above said first plane, and wherein said two driven wheels each supply a motive force to urge said wheelchair on said level surface when said wheelchair is disposed on said first plane;

wherein said wheelchair is adapted to pivot about an axis passing through a center of said two driven wheels from said first plane to a second plane when said wheelchair is disposed on a generally planar and inclined surface that includes a sufficient degree of incline thereto, and wherein a bottom of said two driven wheels and a bottom of said two additional driven wheels define said second plane, and wherein said bottom of said two driven wheels and said bottom of said two additional driven wheels are disposed on said inclined surface when said wheelchair is disposed on said second plane,

wherein when said wheelchair is disposed on said second plane said two driven wheels each supply a motive force to urge said wheelchair on said inclined surface, and wherein when said wheelchair is disposed on said second plane said two additional driven wheels each supply a motive force to urge said wheelchair on said inclined surface, and wherein when said wheelchair is disposed on said second plane said two driven wheels and said two additional driven wheels provide four-wheel drive capability for urging said wheelchair on said inclined surface when said wheelchair is disposed on said second plane;

wherein said two driven wheels include a left driven wheel and a right driven wheel, and wherein said two additional driven wheels include a left additional driven wheel and a right additional driven wheel, and wherein drive means is provided to mechanically link said left additional driven wheel to said left driven wheel and to mechanically link said right additional driven wheel to said right driven wheel sufficient so that said left additional driven wheel always rotates in a direction that is equal to that of said left driven wheel whenever said left driven wheel is rotating and wherein said right additional driven wheel always rotates in a direction that is equal to that of said right driven wheel whenever said right driven wheel is rotating;

wherein a first motive source that is used to rotate said left driven wheel independently with respect to said right driven wheel is also used to rotate said left additional driven wheel independently with respect to said right additional driven wheel, and wherein a second motive source that is used to rotate said right driven wheel independently with respect to said left driven wheel is also used to rotate said right additional driven wheel independently with respect to said left additional driven wheel;

wherein said first of said two driven wheels and said second of said two driven wheels provide differential steering of said wheelchair when said wheelchair is disposed on said first plane, and wherein said first of said two additional driven wheels and said second of said two additional driven wheels do not provide differential steering of said wheelchair when said wheelchair is disposed on said first plane;

wherein said first of said two driven wheels and said second of said two driven wheels provide differential steering of said wheelchair when said wheelchair is disposed on said second plane, and wherein said first of said two additional driven wheels and said second of said two additional driven wheels provide differential steering of said wheelchair when said wheelchair is disposed on said second plane; and

wherein when said wheelchair is disposed on said inclined surface and on said second plane said third of said at least three wheels is not disposed on said inclined surface.

2. The improvement of claim 1 wherein said at least three wheels of said powered wheelchair includes four wheels and wherein said four wheels are disposed on said first plane when said wheelchair is disposed on said level surface.

3. The improvement of claim 2 wherein said four wheels include said at least two driven wheels.

4. The improvement of claim 3 wherein a center of said two driven wheels is disposed behind a center of a remaining two of said four wheels and wherein a center of said two additional driven wheels is disposed behind said axis passing through said center of said two driven wheels, and wherein said remaining two of said four wheels do not supply a motive force to urge said wheelchair on said surface.

5. The improvement of claim 4 wherein said center of said two additional driven wheels is disposed behind said axis passing through said center of said two driven wheels and wherein said two additional driven wheels are disposed between a track of said two driven wheels.

6. The improvement of claim 5 wherein said center of said two additional driven wheels are disposed behind said axis passing through said center of said two driven wheels, and wherein said two additional driven wheels are disposed between said track of said two driven wheels.

7. The improvement of claim 3 wherein said two additional driven wheels include a diameter that is the same as that of said two driven wheels, and wherein said two additional driven wheels are adapted to rotate at the same rate as said two driven wheels rotate.

8. The improvement of claim 3 wherein said two additional driven wheels include a diameter that is less than that of said two driven wheels, and wherein said two additional driven wheels are adapted to rotate at a greater rate than said two driven wheels rotate.

9. The improvement of claim 3 wherein said two additional driven wheels include a diameter that is greater than that of the two driven wheels, and wherein said two additional driven wheels are adapted to rotate at a slower rate than said two driven wheels rotate.

10. The improvement of claim 1 wherein a bottom of said pair of additional driven wheels and a bottom of said two driven wheels are disposed on said second plane when said wheelchair is disposed on said inclined surface.

11. The improvement of claim 1 wherein a center of said two additional driven wheels is disposed behind said axis passing through said center of said two driven wheels.

12. The improvement of claim 1 wherein a center of said two additional driven wheels is disposed forward of said axis passing through said center of said two driven wheels.

13. An improvement to a powered wheelchair that includes at least three wheels, wherein two of said at least three wheels are driven wheels, and wherein a third of said at least three wheels is free spinning, and wherein a bottom of said at least three wheels define a plane that said wheelchair is disposed in when said wheelchair is disposed on a planar and level surface, and wherein said two driven wheels include a left driven wheel and a right driven wheel, and the improvement comprising:

including a left additional driven wheel and wherein a center of said left additional driven wheel is disposed behind a center of said left driven wheel, and including means for mechanically coupling said left driven wheel of said wheelchair to said left additional driven wheel wherein said left additional driven wheel rotates in the same direction as said left driven wheel, and including a right additional driven wheel and wherein a center of said right additional driven wheel is disposed behind a center of said right driven wheel, and including means for mechanically coupling said right driven wheel of said wheelchair to said right additional driven wheel wherein said right additional driven wheel rotates in the same direction as said right driven wheel;

wherein said wheelchair is adapted to pivot about an axis passing through a center of said two driven wheels from said first plane to a second plane when said wheelchair is disposed on a generally planar and inclined surface that includes a sufficient degree of incline thereto, and wherein a bottom of said two driven wheels and a bottom of said left additional driven wheel and said right additional driven wheel define said second plane, and wherein said bottom of said two driven wheels and said bottom of said left additional driven wheel and said right additional driven wheel are disposed on said inclined surface when said wheelchair is disposed on said second plane,

wherein when said wheelchair is disposed on said second plane said two driven wheels each supply a motive force to urge said wheelchair on said inclined surface, and wherein when said wheelchair is disposed on said second plane said left additional driven wheel and said right additional driven wheel each supply a motive force to urge said wheelchair on said inclined surface, and wherein when said wheelchair is disposed on said second plane said two driven wheels and said right additional driven wheel and said left additional driven wheel provide four-wheel drive capability for urging said wheelchair on said inclined surface when said wheelchair is disposed on said second plane;

wherein a first motive source that is used to rotate said left driven wheel independently with respect to said right driven wheel is also used to rotate said left additional driven wheel independently with respect to said right additional driven wheel, and wherein a second motive source that is used to rotate said right driven wheel independently with respect to said left driven wheel is also used to rotate said right additional driven wheel independently with respect to said left additional driven wheel;

wherein said left driven wheel and said right driven wheel provide differential steering of said wheelchair when said wheelchair is disposed on said first plane, and wherein said left additional driven wheel and said right additional driven wheel do not provide differential steering of said wheelchair when said wheelchair is disposed on said first plane;

wherein said left driven wheel and said right driven wheels provide differential steering of said wheelchair when said wheelchair is disposed on said second plane, and wherein said left additional driven wheel and said right additional driven wheel provide differential steering of said wheelchair when said wheelchair is disposed on said second plane; and

wherein when said wheelchair is disposed on said inclined surface and on said second plane said third of said at least three wheels is not disposed on said inclined surface.

14. A method for increasing the versatility of a self-propelled type of wheelchair that includes at least three wheels and wherein two of said three wheels are driven wheels and wherein a third of said at least three wheels is free spinning, and wherein a bottom of said at least three wheels are disposed on a first plane and wherein said bottom of said at least three wheels define said first plane and wherein when said wheelchair is disposed on a level surface it is disposed in said first plane, the method being comprised of the steps of:

providing two additional driven wheels with said wheelchair in addition to said two driven wheels; and

elevating said additional driven wheels above said first plane when said wheelchair is disposed in said first plane;

wherein said two additional driven wheels are disposed above said first plane, and wherein said two driven wheels each supply a motive force to urge said wheelchair on said level surface when said wheelchair is disposed on said first plane;

wherein said wheelchair is adapted to pivot about an axis passing through a center of said two driven wheels from said first plane to a second plane when said wheelchair is disposed on a generally planar and inclined surface that includes a sufficient degree of incline thereto, and wherein a bottom of said two driven wheels and a bottom of said two additional driven wheels define said second plane, and wherein said bottom of said two driven wheels and said bottom of said two additional driven wheels are disposed on said inclined surface when said wheelchair is disposed on said second plane,

wherein when said wheelchair is disposed on said second plane said two driven wheels each supply a motive force to urge said wheelchair on said inclined surface, and wherein when said wheelchair is disposed on said second plane said two additional driven wheels each supply a motive force to urge said wheelchair on said inclined surface, and wherein when said wheelchair is disposed on said second plane said two driven wheels and said two additional driven wheels provide four-wheel drive capability for urging said wheelchair on said inclined surface when said wheelchair is disposed on said second plane;

wherein said two driven wheels include a left driven wheel and a right driven wheel, and wherein said two additional driven wheels include a left additional driven wheel and a right additional driven wheel, and wherein first drive means is provided to mechanically link said left additional driven wheel to said left driven wheel and second drive means is provided to mechanically link said right additional driven wheel to said right driven wheel sufficient so that said left additional driven wheel always rotates in a direction that is equal to that of said left driven wheel whenever said left driven wheel is rotating and wherein said right additional driven wheel always rotates in a direction that is equal to that of said right driven wheel whenever said right driven wheel is rotating;

wherein a first motive source that is used to rotate said left driven wheel independently with respect to said right driven wheel is also used to rotate said left additional driven wheel independently with respect to said right additional driven wheel, and wherein a second motive source that is used to rotate said right driven wheel independently with respect to said left driven wheel is also used to rotate said right additional driven wheel independently with respect to said left additional driven wheel;

wherein said first of said two driven wheels and said second of said two driven wheels provide differential steering of said wheelchair when said wheelchair is disposed on said first plane, and wherein said first of said two additional driven wheels and said second of said two additional driven wheels do not provide differential steering of said wheelchair when said wheelchair is disposed on said first plane;

wherein said first of said two driven wheels and said second of said two driven wheels provide differential steering of said wheelchair when said wheelchair is disposed on said second plane, and wherein said first of said two additional driven wheels and said second of said two additional driven wheels provide differential steering of said wheelchair when said wheelchair is disposed on said second plane; and

wherein when said wheelchair is disposed on said inclined surface and on said second plane said third of said at least three wheels is not disposed on said inclined surface.