GB848540A - Improvements in or relating to dental handpieces having a head enclosing a compressed air turbine for driving a dental tool - Google Patents

Abstract

848,540. Dental engines. SIEMENSREINIGER-WERKE A.G. April 10, 1959 [April 12, 1958]. No. 12252/59. Class 81(2). A dental handpiece has a turbine supported in the head by ball bearings 15, 16, the inner races 21, 22 of which are fixed to the turbine rotor, the outer races 17, 18 being fixed to bushes 19, 20 fixed in the head. The ball bearings are open, the inner races being fixed by pressing or shrinking to the turbine shaft 11. The outer races are fixed by glueing, soldering or shrinking to cup-shaped bushes which form end closures 24, 25 for a tubular housing 8 in which they are fixed by glueing, soldering or shrinking. Air carrying oil mist is supplied tangentially to the turbine through a duct in the handpiece and, after passing through the bearings, passes out of the head, a small portion being directed towards the end 10 of the tool through a gap 39 surrounding the tool and the remainder being exhausted through a channel 30 in the handpiece and a hose attached to the rear of the handpiece. Water which may be directed towards the tool end through a nozzle 41 in the handpiece mixes with the air passing through the gap to form a water-air spray. The handpiece head has a shaft 3 by which it is detachably connected to the handpiece body 4 by a flanged lock nut 36. The tool shank is secured in a bore 31 in the turbine shaft by a radially resilient slotted sleeve 32. A plug 34 at one end of the sleeve has a conical recess for centering the tool and tightly fits the shaft bore 31.