GB1412622A - Dental handpiece - Google Patents

Abstract

1412622 Dental handpieces J C V MITCHELL 7 June 1973 [8 March 1972 2 May 1972 11 July 1972 4 Dec 1972] 10701/72 20266/72 32278/72 and 55912/72 Heading A5R Handpiece: A dental handpiece 2, Fig. 1, comprises an elongate body 32, Fig. 2, connected via a neck 34 to a head 36 housing a rotary chuck for a dental bur 50, the body housing an electric lamp 78 adjacent the neck 34 which is transparent and has an external surface which reflects internally the light travelling in it, a portion 62 of the surface having reduced reflectance so that light issues from it towards the head 36, the neck 34 also encapsulating at least one drive conduit for the chuck. The body 32 also houses a member 42 reciprocable parallel to the axis of the handpiece, the neck 34 housing a conduit 46 having a curved portion 48 terminating adjacent the head 36 and housing a probe (54), Fig. 5, (not shown) connected to the reciprocable member 42 and having a hard tip (58), the probe (54) being reciprocable between a retracted position within the conduit and a projected position beyond the bur 50. Control Unit: A motor-driven handpiece 4 and the handpiece 2 which is turbine-driven are controlled from a unit 6 which has switches 22, 24, 26, 28, 30 for various modes of operation of the handpieces 2, 4. When either handpiece 2, 4 is disengaged from a respective rest 12, a microswitch 14 is closed to cause the handpiece to be supplied with electricity, air and water. The speed of the bur 50 is controlled from a boot-operated switch 8. Handpiece Body: The reciprocable member 42 consists of a piston in a cylindrical housing 40 which together form a pneumatic ram 38 whose position is controlled by air from tubes 44. The conduit 46 extends from the housing 40 through the body 32. The lamp 78 is cooled by air from an exhaust conduit (65), Fig. 3 (not shown) of the turbine or from another conduit 84. The neck 34 houses the conduit 46 and a conduit (72) for water which is ejected towards the bur 50. A flexible sleeve 98 covers the body 32 and the neck 34. In an alternative embodiment, the bur 50 is driven by a micromotor (88), Fig. 4, (not shown) via a flexible drive cable. Probe: The probe (52) is formed from a cylindrical wire of stainless steel, and has a head portion (54) integral with a tail portion (56) of reduced diameter. The tail (56) is annealed so that it is softer than the head (54) so that the probe (52) can slide easily in the conduit 46. Air from the housing 40 is passed through the conduit 46 and emerges near the end of the conduit (72) and atomises the water issuing therefrom.