US Patent 7723880 Hand crank generator

A hand crank generator includes a crank, a gear transmission, and a generation motor driven by the gear transmission. The crank and the gear transmission are coupled to each other. A clutch gear is coupled between the crank and the gear transmission. The crank is manually driven to further drive the gear transmission, and the generation motor is driven to generate electric current through the clutch gear. When the cranking stops, the clutch gear disengages from a motor gear disposed on the generation motor. A weighted wheel continues to revolve under inertia for a while to drive the generation motor to keep on generating electric current, so that the purpose of saving manual efforts can be achieved.