Patent ID: 6478711
Filing Date: 2002-11-12
Classification: B62M

Abstract:
An apparatus for changing the speed of a bicycle having a rear driving wheel, the apparatus comprising:a driven sprocket for receiving the driving force of a driving sprocket; a speed controlling portion, comprising: a carrier fixed to one side of the driven sprocket, a plurality of planetary gears within said carrier, each of said planetary gears having at least a first tooth portion and a second tooth portion; at least two sun gears, each having ratchet-teeth along its inner circumference, one of said sun gears being engageable with said first tooth portion of each of said planetary gears and a second of said sun gears being engageable with said second tooth portion on each of said planetary gears; a ring gear engageable with the planetary gears; an output portion, comprising: a hub shell for transferring the driving force to the rear wheel of the bicycle by means of the carrier and the ring gear; a clutch means, mounted between the carrier and hub shell and the ring gear and the hub shell to selectively mediate the driving force; and a speed-change controlling portion, comprising: a hub shaft having a pawl-positioning portion; at least two sets of pawls engageable with and releasable from the ratchet-teeth of the sun gears; a pawl-controlling ring for controlling the position of the pawls; a transforming disk having a groove along its outer circumference, and a hooking portion on said outer circumference, said hooking portion adapted to transform the position of the pawl-controlling ring through a mediating portion; a spring for restoring the position of the transforming disk to its original position; and a spacing portion enabling the transforming disk to rotate freely.