Abstract: A power driven wheel chair is described which includes a rear wheel support frame and at least two ground engaging rear wheels mounted in spaced relation to opposed sides of the rear wheel support frame. A front wheel support frame is pivotally secured to the rear wheel support frame for pivotal movement about a substantially horizontal axis. At least two ground engaging front wheels are mounted in spaced relation to opposed sides of the front wheel support frame. A drive motor provides motive force to at least one wheel of one of the pairs of at least two ground engaging wheels. A chair is mounted on one of the rear wheel support frame and the front wheel support frame. The wheel chair, as described, has added stability as relative pivoting of the rear wheel support frame and the front wheel support frame maintains the wheels in contact the ground at all times.

Abstract: A reversible variable speed drive mechanism is disclosed formed of an engine crankshaft and a balancing shaft parallel to the crankshaft. A second pulley is non-rotatably secured to a first end of the balancing shaft. The second pulley is coupled to a first pulley at a first end of the crank shaft by a belt. The second pulley has a belt supporting circumference which is adjustable such that the speed of the balancing shaft is adjustable by altering the circumference around which the belt travels. A planetary gear assembly is coupled to a second end of the crankshaft. The balancing shaft sprocket is coupled by a chain to a sprocket on the planetary yoke such that the rotation of the planetary yoke is coupled to the rotation of the balancing shaft. By altering the rotational speed of planetary yoke relative to an input gear, the output gear can be made to rotate in a first direction, in a second direction or assume a neutral stationary position. A locking sprocket is rotatably mounted on the balancing shaft.