Patent ID: 8137102

Claim:
A fluid-operated medical or dental handheld element comprising a connecting device for connecting the handheld element to a fluid source, a fluid conducting device arranged between the connecting device and a first impeller for conveying a fluid stream toward or away from the first impeller, wherein the first impeller can be induced by fluid to rotate and is connectable to a tool so that the tool can be induced by the first impeller to execute a working motion, a generator for generating electric power, wherein the generator comprises a second rotatable impeller positioned in series relative to the first impeller and driveable by at least a substream of the fluid stream conveyable in the fluid conducting device, an outer sleeve within which at least the generator is located, the outer sleeve serving as a return passageway which conveys the drive fluid that has passed the second impeller and the first impeller towards the connecting device, wherein the second impeller is constructed as an excess pressure turbine or reaction turbine driveable by the static pressure or the enthalpy decrease of the drive fluid while the dynamic pressure or the kinetic energy of the drive fluid is approximately the same upstream and downstream from the second impeller, and wherein the first impeller is constructed as an equal pressure turbine or action turbine driveable by the dynamic pressure or the kinetic energy of the drive fluid while the static pressure or the enthalpy of the drive fluid is approximately the same upstream and downstream from the first impeller.