Patent ID: 9630680
Date: 2017-04-25
CPC Classifications: B62M

Claim:
1. A two-speed bicycle transmission whereby pedaling backward inherently provides a higher forward driving speed ratio between a bicycle crank with an axis of rotation as input and a bicycle rear hub with an axis of rotation as output comprising: A) a bicycle frame which provides a fixed parallel relationship between the axis of rotation of said bicycle crank and the axis of rotation of said bicycle rear hub; B) a drive sprocket coaxial with the axis of rotation of said bicycle crank and rigidly connected to said bicycle crank; C) a lower speed ratio driven sprocket coaxial with the axis of rotation of said bicycle rear hub and in substantial coplanar alignment with said drive sprocket, wherein said lower speed ratio driven sprocket is separately interfaced to said bicycle rear hub by a first overrunning clutch such that only a forward driving effort is transmitted to said bicycle rear hub; D) a higher speed ratio driven sprocket coaxial with the axis of rotation of said bicycle rear hub and located between said lower speed ratio driven sprocket and said bicycle rear hub, wherein said higher speed ratio driven sprocket is separately interfaced to said bicycle rear hub by a second overrunning clutch such that only a forward driving effort is transmitted to said bicycle rear hub; E) an idler sprocket with an axis of rotation proximate but skewed with respect to the axis of rotation of said bicycle crank and located between said drive sprocket and adjacent members of said bicycle frame, wherein F) an endless chain that connects the following: G) wherein the location, pitch diameter and skewed axis of rotation of said idler sprocket all combine to