Patent GB-1048358-A (GB)
Title: Improvements in or relating to a dental drilling machine
IPC: A61C1/06
Filed: 1965-10-07
Abstract: 1, 048, 358. Dental drilling machines. SIEMENS-REINIGER-WERKE A.G. Oct. 7, 1965 [Oct. 10, 1964], No. 42680/65. Heading A5R. A dental drilling machine consists of an electric motor, cooled with compressed air, and arranged in a cylindrical housing 1 one end face of which is provided with electrical connections for the supply of current to the motor and with an aperture for the throughflow of cooling air and is covered by a cap 2, and whose other end face has the shaft of the motor projecting through it, and of a handpiece 4 adapted to be fitted on the motor shaft. The machine is characterized by having the electrical connection leads and the lead for the compressed air taken into the cap and terminating therin the electric connection leads terminating at electric contact elements in the cap, which are constructed as associated contacts with the electric connection contacts at one end face of the motor housing. The cap is also connected to the motor housing in such a manner as to be releasable, but without substantial rotational movement of cap and housing relative to one another. For instance, the connection may be made by means of a union nut or bayonet joint. As shown, a typical embodiment has head 5 having burr 6 connected to cap 2 by means of plug 8 at end of plastic hose 7. The head 5 is supplied with spray for cooling the drilling zone through said hose. Drive 12 of line handpiece 4 is connected by means of coupling 11 to the driving shaft of the motor. The end plate 15 of the motor housing has a concentric bore 16 for supply of cooling air, and two electrical contact strips 19 and 20. Cap 2 consists essentially of housing 26, insulating part 29. insulating disc 31 and union nut 24. Housing 26 has bores 32, 33 into which tubular connection necks 34, 35 are soldered, and bores 38 and 39, which only project partially into the housing, having tubular connection necks 36, 37. Bores 40, 41 connect with bores 38, 39 and open into tubular connection necks 42, 43 of plug socket 9. The four tubular connection necks 34 to 37 fit into ducts 44 to 47 of hose 3, which may be made of rubber or plastics. Duct 44 is used for supplying compressed air, duct 45 for accommodating current supply leads 48, 49, duct 46 for supplying air to socket 9, and duct 47 for water to socket 9. Hose 3 may be fixed to the connection necks by binding 50. Current supply leads 48, 49 pass through bore 32 and disc 31 to be connected in insulating part 29 to contact springs 55, 56. Said springs and their associated contact strips 19, 20 may be replaced by other contact forms e.g. plug pins and sockets. Sleeves 60, 61 of plug part 8 open into mixing chamber 62. Alternatively, mixing chamber may be omitted and two hoses may be connected to head 5 by means of two tubular connection necks on plug 8 (not shown). Water or air alone may be used, instead of spray, to cool the drilling zone. Alternatively, water from cap 2 may be passed through plug 8 and a single hose to head 5 and cooling air may be made to issue from a bore at the head 5, instead of from the transverse bore 10 at the rear end of the handpiece 4, so that it forms a spray with the water.