Pedal mechanism for a human propulsion vehicle

A pedal mechanism for a human propulsion vehicle having a frame, said pedal mechanism comprising:

• a power transmitting axle having two ends;
• a case fixed at each end of said axle;
• a sun gear rigidly attached to the frame adjacent each of said axle, said sun gears extending within the adjacent cases;
• a planetary gear having a diameter identical to the one of the sun gears, each of said planetary gears being rotatably attached to one of the cases and meshed to the adjacent sun gear, each planetary gear having a radially projecting lever connected thereto, said lever having a free end on which is mounted a fixation pin extending parallel to said planetary gears;
• two parallel pedal arms slidably mounted on said cases respectively, each pedal arms having two ends, a hole made in one of said ends, in which the fixation pin of the adjacent lever is rotatably inserted, and means to attach a pedal at the other of said ends, each pedal arm having a rotation cycle comprising two halves;
• a guiding means pivotally attached to each case to guide and support the corresponding pedal arm when it is moved in and out from the case;
• whereby, in use, forces applied onto said pedals brings in rotation said rotatable cases which themselves rotate said axle and force said planetary gears to rotate around said sun gears, said levers on said planetary gears being arranged so that each pedal arm slides away from said axle at a position in one of the halves of the cycle where said applied forces are to be maximum in order to have a maximum torque on said axle, said pedal arms also having an..angular displacement with respect to a radial centerline intersecting the sun gear and the guiding means wherein said one half of the cycle having said forces at maximum, is longer than the other half.