| 摘要 |
PROBLEM TO BE SOLVED: To provide an air turbine hand-piece for preventing a vacuum from being created in a turbine chamber by the inertial rotation of an air turbine rotor when the use of the air turbine hand-piece is ended to stop the air supply.SOLUTION: An air turbine hand-piece 1 comprises: an air supply conduit 11 for driving an air turbine rotor 6 of a turbine chamber 15; an exhaust conduit 12 for exhaust; and a return conduit 16 having its one end 20a communicating with the exhaust conduit 12 and its other end 20b communicating with a return port 17 opened in the vicinity of an air supply port 14 of the air supply conduit 11 opened in the turbine chamber 15, so that the vacuum to be established in the turbine chamber 15 is prevented while the exhaust by the inertial rotation of the air turbine rotor 6 at the stop of the air supply is being returned through a return passage 16, wherein the return passage 16 is formed between a return groove 20 formed in a wall face 15a of the turbine chamber 15 and a wall face 25a of a housing 25 fitted in the turbine chamber 15. |
