Propulsion system for human powered vehicles

A leveraged propulsion system for human powered vehicle, comprising:

• an outer lever having an input end and an output end, the outer lever being configured to receive a force input from a human limb at the input end;
• an orbiting sprocket being coupled to the output end of the outer lever;
• a fixed sprocket, wherein the orbiting sprocket orbits around the fixed sprocket, the orbiting sprocket and the fixed sprocket being located in a substantially common plane, and being offset one from another;
• a first closed tension-bearing member engaging an outer circumference of both the orbiting sprocket and the fixed sprocket;
• a crank lever spanning the distance between the fixed sprocket and the orbiting sprocket, the crank lever also maintaining a relative distance between the orbiting sprocket and the fixed sprocket,
• a driveshaft being coaxial with the fixed sprocket, the driveshaft being free to rotate with respect to the fixed sprocket the crank lever being fixedly connected to the driveshaft and rotationally connected to the orbiting sprocket;
• a drive sprocket located on the driveshaft;
• a drive wheel having a drive-hub;
• a freewheel drive device being located on the drive-hub;
• a second closed tension-bearing member connecting the drive sprocket and the freewheel drive device located on the drive-hub;
• a chassis being driven by the drive wheel;
• and
• wherein application of a force on the input end of the outer lever causes the orbiting sprocket to orbit around the fixed sprocket and thereby rotate the crank lever which imparts rotation to the driveshaft and thereby provide rotation to the drive wheel which thereby imparts propulsion to the vehicle.

A method for propelling a human powered vehicle comprising:

• providing an outer lever having an input end and an output end, the outer lever being configured to receive a force input from a human limb at the input end;
• providing an orbiting sprocket being affixed to the output end of the outer lever, the output end of the outer lever being rigidly affixed to the orbiting sprocket;
• providing a fixed sprocket, wherein the orbiting sprocket orbits around the fixed sprocket and where the orbiting sprocket and the fixed sprocket are located in a substantially common plane, have a common radius, and are offset from one another;
• affixing a first closed tension-bearing member so as to engage an outer circumference of both the orbiting sprocket and the fixed sprocket;
• providing a crank lever to span the distance between the fixed sprocket and the orbiting sprocket wherein the crank lever is configured to maintain a relative distance between the orbiting sprocket and the fixed sprocket;
• applying a force to the input end of the outer lever so as to cause the orbiting sprocket to orbit around the fixed sprocket;
• and
• wherein the orbiting motion of the orbiting sprocket drives the crank lever and causes the crank lever to rotate about a driveshaft which propels the human powered vehicle.