Patent ID: 6802798
Filing Date: 2004-10-12
Classification: A63B,B62M,Y10T

Abstract:
An adjustable oval pedal trace extending crank mechanism comprising:a power transmitting shaft having two ends; a crank assembly fixed at an end of said shaft; a sun gear rigidly attached to a frame adjacent to said shaft; a planetary gear having half of the diameter of said sun gear; said planetary gear being rotatably attached to said crank assembly and meshed with said adjacent sun gear, said planetary gear having one end of a radially projecting arm connected thereto, said projecting arm having an extending arm rotatably fixed at the other end of said projecting arm; a slidable pedal crank retained on said crank assembly; the extending arm rotatably fixed on the slidable pedal crank of said crank assembly, the extending arm being driven to move back and forth by said projecting arm when said planetary gear rotates along with said sun gear; and the slidable pedal crank having the extending arm rotatably fixed to a position hole on the slidable pedal crank, said slidable pedal crank moving back and forth synchronically with the rotation of said crank assembly; said slidable pedal crank having a threaded hole at the end thereof to install a pedal thereon; wherein forces applied onto said pedal drive said rotatable crank assembly to rotate, said rotatable crank assembly drives said shaft and said planetary gear to rotate around said sun gear, and said projecting arm on said planetary gear is arranged, such that said pedal crank slides back and forth from said shaft at a position in one of the halves of the cycle.