Patent ID: 7311160
Filing Date: 2007-12-25
Classification: A61G,Y10S

Abstract:
1. A foldable wheelchair comprising: a foldable X-shared chair frame for having a seat on the X-shaped chair frame; a pair of auxilary power units respectively having motors and decelerators at opposite rear portions of the foldable X-shaped chair frame; a pair of drive wheels respectively having cylindrical hollow drive wheel hubs on the opposite rear portions of the foldable X-shaped chair frame; a pair of wheel hub ratchet clutch devices respectively in the hollow drive wheel hubs for selectively engaging/disengaging the auxiliary power units with the drive wheel hubs and, thereby, the drive wheels; a pair of caterpillars respectively on opposite front portions of the foldable X-shaped chair frame; means for driving the caterpillars with the drive wheel hubs when the wheel hub ratchet clutch devices selectively engage the auxiliary power units with the drive wheel hubs, whereby to drive the foldable X-shaped chair frame with the drive wheels and caterpillars; a caster wheel at a symmetric center of the front portion of the foldable X-shaped chair frame; and means for lowering the caster wheel from a position above the caterpillars to a position below the caterpillars, whereby to raise the caterpillars from the drive thereof.