Abstract: A high speed turbine handpiece includes a housing with a turbine wheel chamber and a flow passage for air terminating in a nozzle opening on the periphery of the turbine wheel chamber as well as a discharge passage from the chamber to the exterior of the housing. An integrally formed turbine wheel in the chamber has a hub with two axially spaced sets of vanes extending about its circumference with the blades of one set circumferentially offset from the blades of the other set. The nozzle is aligned with the axial spacing or channel between the sets of vanes and is dimensioned to overlap the adjacent edge portions of the vanes so that air entering through the nozzle impinges on both sets of vanes.

Abstract: A method and apparatus for controlling speed and torque of hand held air driven vane type motors is available in several embodiments. For example, one embodiment is used in tool and die work and another embodiment is used in dental work. In reference to the latter, a foot operated control regulates the speed of an air driven handpiece, driving in turn various tools such as cutters and drills as they are generally used in a dental laboratory, by regulating the flow of compressed air both to and from the handpiece. Application of an operator's foot pressure on a floor level foot control, simultaneously depresses two valves which control the flow of compressed air. One valve controls the flow of compressed air from its source to the handpiece, and one valve controls the release into the atmosphere of compressed air from the handpiece.