Adjustable wheelbase wheelchair

摘要

A multi-wheeled vehicle having adjustable wheelbase dimensions. The preferred embodiment is a wheelchair which affords on-the-fly adjustment of width. The linkage between the two side frames of the present wheelchair is of two cross members in a horizontal X configuration, one end of each cross member being pivotally affixed to one side frame on one side of the wheelchair, with the respective other end of each cross member being slidably engaged with the opposite side frame. The cross members are pivotally attached to each other at a point of intersection. This structure allows a wheelchair of the present design to be easily expanded and contracted in width during use, with the rider in-place, and avoids the necessity of incremental changes between uses, such as is required by wheelchairs of present design. Yet, such a wheelchair is structurally quite stable with respect to any tendency of the side frames to toe-in under torque applied by weight on the seat.