A wheelchair for climbing stairs and curbs, comprising:
- a chair seat;
- paralleling elevating levers adjacent each side of said chair, said levers including a plurality of parallel bars substantially horizontally oriented, said chair fastened to said lever bars, whereby the levers are free to pivot vertically in parallel abut said chair fastening while the chair seat remains always substantially horizontal;
- a first pair of linear bearings, one adjacent each side of said chair, said bearings having an outer race slide to which one end of said parallel lever bars is pivotably fixed such that said bearings remain substantially horizontally oriented parallel to the chair seat, and an inner race slide connected through a vertical support member to a first frame means, vertically pivotable about said connection, upon which are mounted a plurality of wheelchair-supporting and transporting wheels, which frame, upon pivoting causes vertical articulation of said wheels, whereby said chair may be supported in a level position with some of the wheels resting on one stair tread or surface and others on another stair or surface at a different elevation;
- a second pair of linear bearings, one adjacent each side of said chair, said bearings having an outer race slide to which the opposite end of said parallel lever bars is pivotally fixed such that said bearings remain substantially horizontally oriented parallel to the chair seat, and an inner race slide connected through a vertical support member to a second frame means, vertically pivotable about said connection, upon which are mounted a plurality of chair-supporting feet means, which frame, upon pivoting, causes vertical articulation of said feet, whereby said chair may be supported in a level position with some of the feet resting on one stair tread or surface and with others on another stair or surface at a different elevation;
- means for adjusting the height of said wheels, while said feet support said chair, between a chair-supporting position and an elevation at least one stair riser high;
- means for locking said elevated wheels in a position when said wheels are articulated substantially to the slope of said stairs;
- means for adjusting the height of said feet, while said wheels support said chair, between a chair-supporting position and an elevation at least one stair riser high;
- and
- means for locking said elevated feet in a position when said feet are articulated to substantially the slope of said stairs,
- wherein stairs are climbed by backing said wheelsupported wheelchair up to the bottom stair of said stairs, adjusting said feet downwards to support said chair, adjusting the wheels upwards more than one-half a stair riser in height, whereby said chair is elevated about one-half that of the wheels by operation of said elevating levers connected through slide bearings and frame to said wheels, articulating said wheels such that those wheels closest to the first stair are at least slightly higher than said stair tread, sliding said wheels by means of said first linear slide-bearing inner race slide toward said stairs until wheels sufficient to support the chair are resting on the ground level and the first stair tread, locking said wheels from rotation and lowering said wheels downward into chair-supporting contact with said ground level and said first stair tread, sliding by means of said first and second slide-bearing outer race slides said chair seat toward said first stair until substantially centered over said wheels, adjusting said feet in elevation upwards more than one-half of a stair riser in height, whereby said chair is elevated by operation of the elevating levers connected through slide bearings and frame to said feet, articulating said feet such that those feet closest to the first stair are at least slightly higher than said stair tread, sliding said feet by means of said second linear slide-bearing inner race toward said stairs until feet sufficient to support the chair are resting on the ground level and the first stair tread, adjusting and locking said feet downward into chair-supporting contact with said ground level and first stair tread, wherein said sequence of operation less the articulation steps is repeated until said stairs are climbed and said wheels are again in supporting and transporting position on level ground.