Patent ID: 7448869

Claim:
Medical or dental handpiece comprising a treatment tool driven by a drive part via a transmission arrangement, the transmission arrangement comprising: first and second transmission stages connected one after another, each of the first and second transmission stages having, a sun gear mounted on a drive shaft, and a planetary gear carrier having a plurality of uniformly distributed planetary gears cooperating with the sun gear, the planetary gear carrier of the first transmission stage serving as a drive shaft and carrier of the sun gear of the second transmission stage; and a hollow gear, fixed to a housing, surrounding the plurality of planetary gears of both the first and second transmission stages, the hollow gear having an inner toothing, wherein the drive shaft for the first transmission stage extends beyond the sun gear driven by the drive shaft of the first transmission stage and the planetary gear carrier associated with this the sun gear driven by the drive shaft of the first transmission stage is arranged rotatably on a portion of the drive shaft for the first transmission stage that extends beyond the sun gear driven by the drive shaft for the first transmission stage.