Patent GB-869672-A (GB)
Title: Improvements in or relating to high-speed angle-handpieces for dental purposes
IPC: A61C1/05
Filed: 1958-10-08
Abstract: 869,672. Dental engines. KALTENBACH, A., and HOFFMEISTER, E. Oct. 8, 1958 [Oct. 10, 1957; Dec. 14, 1957], No. 32157/58. Class 81 (2). In a high-speed angle hand piece, tubes through which compressed air and water are supplied to the head and part at least of the air is discharged are divided transversely at the disconnectible joint between a handle sleeve and a head sleeve, or within the head sleeve and sealed when the sleeves are connected by a packing mounted on a support within the hand piece. As shown, Fig. 2, air and water supply pipes 9 and 10, respectively, are welded in a support in the form of an elbow piece 2, welded to the handle sleeve 16, on which is screwed a ring 21 carrying a packing 19. The tubes 9 and 10 are inserted in bores 28, 29 in an insert 27 welded in a head sleeve 26, and the end 31 of the insert is sealed against the packing 19 by screwing a clamping nut 23 which has a flange 22 engaging the ring 21 on to the threaded portion 30 of the head sleeve. Compressed air is supplied to a stub pipe 4 and passes to a bore 6 which receives the pipe 9, a water-pipe 8 passing through the pipe 4 to a bore 7 which receives the pipe 10. A cap 11 supporting a packing 14 fits over an enlarged part of the tube 4 and the assembly is secured in the handle sleeve 16 by a nut 15 which, when tightened, causes the disc 14 to seal the pipes 9 and 10 in the bores 6 and 7. The head 25 encloses a housing 33, 34 for a turbine 35. The turbine shaft is mounted on bearings 36 and 37, the outer races of which are held respectively in a forward part of the head and the housing 33 and in a cap 32 and the housing 34. A small amount of air is discharged from the turbine through the bearing 37 and holes 39 in the cap 32 and through the bearing 36 and holes 40. The major portion passes through a bore (not shown) in the insert 27, corresponding holes in the packing 19 and elbow-piece 2 into the interior of the sleeve 16 and is discharged through holes 45, Fig. 6. Air issuing from the holes 40 atomizes a fine jet of water from a hole 46 leading from the bore 29 for cooling the tool. In another embodiment, Fig. 7, an air pipe 83 supporting a water pipe 79 is inserted in an elbow piece 71 which is secured by brazing to a handle sleeve 70 and has a packing 76 mounted to allow rotary movement in an undercut recess. The water pipe 79 communicates with bores 78 and 77 in the elbow piece and packing, respectively. The pipe 83 communicates through ports 82 and an annular duct 81 with apertures 80 in the packing arranged on a circle concentric with the bore 77. A gripping-ring 73 is connected for rotary movement only to the elbow piece 71 by means of a spring-ring 72 and receives studs 69 on the head sleeve 53 in longitudinal slots 74 which merge into oblique slots 75 to form a bayonet joint. An insert 54 in the head sleeve supports a ring 59 of which a portion 60 carries a water-pipe 55 and which has an annular air chamber 63 and ports 61. When the sleeves are connected, air passes from the apertures 80 through the chamber 63, ports 61, ducts 62, 57 and a further duct (not shown) to the turbine housing. Air discharged from the housing passes through a duct (not shown), an annular duct 66, bores 67, a chamber 68, bores 85, and annular duct 86 and bores 87 to the interior of the handle sleeve and thence to atmosphere. The head sleeve 53 and associated ring 73 may be rotated relative to the handle sleeve.