| 摘要 |
851,110. Dental handpieces. SIEMENSREINIGER-WERKE A.G. April 22, 1959 [April 26, 1958], No. 13766/59. Class 81(2) In a dental handpiece in which a turbine for driving a tool is disposed in the head, the turbine and the bearing elements therefor are enclosed in a radially resilient sleeve to form a unit which fits in a tubular chamber in the head. The head of the handpiece comprises a cup-shaped housing 7 into which is inserted the unit comprising a turbine rotor 11, rear and forward ball bearings 13,14 and annular bearing bushes 21, 22. The unit is enclosed in a resilient sleeve 23 having a longitudinal slot which enables it to be opened out and which engages pins 25 projecting inwardly of the housing to secure the unit against rotation. Inclined guiding faces 26, 27 at each end of the sleeve engage corresponding guiding faces 28, 29 in the housing 7 and a rear threaded cover 9, respectively. Air carrying oil mist passes through a duct in the handpiece and is directed tangentially against the turbine. The air passes out of the head through a gap 37 towards the end of a tool mounted in the turbine shaft by a sleeve 31, and also by way of the rear and forward bearings and apertures 40, 41, 42, 43 in the bushes and resilient sleeve 23 respectively into a collecting channel 39 which extends through the handpiece. Water is supplied to the end of the tool through a duct 44 and a nozzle 45 in the handpiece. |
