HIGH-SPEED DENTAL DRILL

摘要

A high-speed dental drill is comprised of a hand piece having a drill head at an end thereof. A turbine assembly is supported in a turbine chamber inside the drill head. The turbine assembly has a chuck which is rotatably secured between bearings. An impeller is secured about the chuck and aligned with an air inlet port in a sidewall of the turbine chamber. An exhaust port is provided in the sidewall to exhaust air. An air conduit is provided in the handpiece to direct air pressure to the air inlet port to drive the turbine and rotate the chuck. The chuck has a work bit engaging free end which is exteriorly accessible. An insert is secured to the drill head and provides access to the turbine chamber. The insert has a smooth conical tapered circumferential external sidewall for frictional engagement by a mating conical bore of a key for the removal and connection of the insert. The exhaust port has a non-circular cross-section in which the aspect ratio of the exhaust port is not equal to one. The handpiece, the drill head and the insert are all radially symmetric to facilitate cleaning and sterilization as well as manufacturing.