VEHICLE AND METHOD FOR OVERCOMING FLIGHTS OF STAIRS BY VEHICLE (VERSIONS) Russian patent published in 2003 - IPC

FIELD: vehicles for ascending stair flights. SUBSTANCE: according to first version, method involves setting average value of wheeled chair wheel base within the range of from L1 to L2, with telescopic frame being fixed, for providing optimal conditions for development of required draft by meshing of one pair of wheels sufficient for lifting other pair of wheels to subsequent stair; rotating all the wheels upon fixing of telescopic frame. According to second version, method of ascending vehicle with movable telescopic frame within the range of from L1 to L2 involves expanding frame, when rear wheels 5 are within their friction angles on stair and front wheels are rotating, until front wheels 4 are introduced within angle (α) of friction with subsequent stair; drawing together frame, with front wheels being within angles of friction until rear movable wheels are introduced within angles of friction with subsequent stair. Frame may be expanded to maximum extent for providing high-speed movement on open road. EFFECT: intensified ascending of wheeled chair on stairs and wider operational capabilities. 19 cl, 28 dwg