GB790737A - Improvements in or relating to angle handpiece heads for dental purposes - Google Patents

Abstract

790,737. Dental handpieces. KALTENBACH, A., and HOFFMEISTER, E. May 10, 1956 [May 10, 1955], No. 14630/56. Class 81 (2). A dental angle handpiece, in the head of which a tool shank may be locked, has a drill sleeve cap which is inserted without a bearing and is centred only by the tool shank. The drill sleeve cap 19, Fig. 9, having driving teeth 42 surrounds a tool shank 15 and has a milled slot 20, Fig. 12, which engages driving flats 16 on a thickened portion 14 of the tool shank. The rear end of the tool shank is guided by an intermediate element 21 held in the handpiece by a. metal plate 22 welded to the element and held in place by a screw 23 which holds a locking lever 4 to the handpiece. The shank may be locked in the handpiece by engagement between an annular groove 18, Fig. 15, a bush 17 on the tool shank and either a hook (not shown) located in the locking lever or the inclined end 25 of a slotted spring 24, Fig. 16, in the locking lever 4. A hard metal or sapphire bearing 33 is fitted in the front end of the handpiece head. In an alternative construction, the tool shank is locked by engagement between the annular groove 18 on the tool shank and a nose on a spring-pressed slide arranged in a dovetail slot on the handpiece head. The bushing 17 may be omitted from the tool shank, in which case a sapphire or hard metal bearing is provided in the intermediate element 21.