GB1153074A - Air Driven Dental Hand Piece - Google Patents

Abstract

1,153,074. Dental handpieces. AMERICAN HOSPITAL SUPPLY CORP. 31 Aug., 1966, No. 38795/66. Heading A5R. [Also in Division F2] An air-driven dental handpiece comprises an air turbine, two-speed epicyclic transmission means, speed-reducing transmission means operative between the turbine and the twospeed epicyclic transmission means, and a speed-selection control means including a manually operable frictional clutch which selects which of the two speeds is operative. As shown, the dental turbine handpiece is arranged so that the drive to the burr may be reversed and also adjusted for speed and comprises a turbine rotor having a first set of blades 33 facing in one direction and a second set of blades 34 facing in the opposite direction, the rotor being coupled through planetary gear rings (44) (Figure 3, not shown) and bearings 47 to a pulley 45 and thence to a second set of planetary gear rings (72) (Figure 4, not shown) having a clutch mechanism which provides a variable drive to the chuck shaft 82. Air is supplied to the turbine rotor via a conduit 14 and is directed to either set of turbine blades through conduits 16 or 17 by moving a valve member (20) (Figure 7, not shown). The clutch mechanism and speed control is actuated by rotating a knurled ring 61 which, through a spigot 60 (see also Figure 6, not shown), moves a shaped annular member 56 from stationary clamped engagement with the handpiece housing 50 through an intermediate partially slipping condition until it is in rotating clamped engagement with an inner wedge shaped member 53. The member 53. is provided with bearings 67 and is rotated by the pulley 45 via planetary rings (72) (Figure 4, not shown) engaging in the space 69 between the pulley 45, the annular member 56 and the bearings 67, the rings (72) driving .the member 53 at a speed dependent on the freedom to rotate of the member 56. The member 53 is connected to a shaft 48 driving the chuck of the handpiece. The handpiece also includes a knob 81 used to actuate a central shaft 80 which adjusts the chuck, a button 84 which can lock the shaft 48 to facilitate adjusting the chuck, and an air exhaust conduit 15.