Patent ID: 8142326

Claim:
A multi-gear mechanism for power tools, comprising: a first gear set having a first central hole and teeth defined on an outside thereof; a second gear set having a second central hole and teeth defined on an outside thereof; multiple first planet gears pivotably connected between the first and second gear sets by first pins; an output set; multiple second planet gears pivotably connected to the output set by second pins; a first gear ring including external teeth defined on an outer periphery thereof and internal teeth defined on an inner periphery thereof, the second planet gears located within the inner periphery of the first gear ring and engaged with the internal teeth; a motor gear extending through the first and second central holes of the first and second gear sets, the first planet gears and the second planet gears engaged with the motor gear; a second gear ring having side teeth on a side thereof and internal teeth defined on an inner periphery of the second gear ring, the first planet gears and the second gear set located within the inner periphery of the second gear ring, the internal teeth engaged with the first planet gears and the teeth of the second gear set, the side teeth engaged with the outside teeth of the first gear ring, and an operation gear ring including internal teeth defined on an inner periphery thereof, the first gear set located within the inner periphery of the operation gear ring and the internal teeth of the operation gear ring engaged with the teeth of the first gear set, the operation gear ring being connected with the second gear ring.