GB797338A - Improvements in or relating to dental drilling units - Google Patents

Abstract

797,338. Dental engines. RITTER CO., Inc. Jan. 7, 1957 [Jan. 9, 1956], No. 598/57. Class 81 (2). In a dental drilling unit the articulated support arm is formed from tubular rods and flexible tubes, for conveying air and water to the handpiece, pass through these rods and are led externally around their joints. A twoarmed bracket 33 is mounted for rotation about a vertical pivot in the stand 11 and carries pivots 34 on which the arm 13 is mounted, while a rearward extension 36 carries the motor 42 to counterbalance the arm and its appendages. The motor pulley is mounted at the lower side of the motor so that the cord extends through the hollow arm 13 to pulleys at its outer end and thence externally over guide pulleys carried by articulated rods 103, 91 to the handpiece 16. The arm 13 is made in the form of a channel member 52, closed at its lower side by a plate 51 and having a telescopic, tubular extension 57, the position of which is adjustable by a knurled nut 66 to determine the tension of the driving cord. Air and water, under pressure, are supplied through pipes 117, 118, Fig. 4, to bores 123, 132, in the centre pivot 25, through annular recesses 121, 129, separated by a sealing ring 136, and through drillings 122, 131. Metal pipes 127, 134 connect with these bores and flexible tubes, connected thereto, run through the hollow arm 13, Fig. 1, to jets 151 on the handpiece. The flexible tubes are protected, where they pass around the joints in the articulated arm, by coil springs 158, 158, 169 but, for the length of the rods 91, 103 they pass through longitudinal drillings formed through them.