Patent GB-1131261-A (GB)
Title: Improvements in or relating to a dental apparatus unit having a plurality of handpieces
IPC: A61C1/00
Filed: 1966-02-04
Abstract: 1,131,261. Dental unit comprising a plurality of handpieces. SIEMENS - REINIGER WERKE A.G. 4 Feb., 1966 [10 Sept., 1965], No. 5116/66. Heading A5R. A dental apparatus unit comprises separate first and second handpieces each of which is adapted to be retained in and to be withdrawn from a respective handpiece holder, the first handpiece being directly drivable by a compressed-air motor and the second handpiece being drivable by a small electric motor which is directly coupled to or incorporated in the second handpiece. The unit further includes a first conduit for connecting a source of compressed air to the motor in the first handpiece, a second conduit for connecting the source of compressed air to the second handpiece for cooling the electric motor with compressed air, and a valve system which is arranged in the conduits between the source of compressed air and the handpieces and which incorporates switch means operable to control the valve system in a manner such that the conduit leading to the first handpiece is opened in dependence on withdrawal of the first handpiece from its holder and the conduit leading to the second handpiece is opened in dependence on withdrawal of the second handpiece from its holder. As diagramatically illustrated in Figure 1, a dental apparatus unit comprises a housing 4 having holders in the form of sleeve rests in which are retained a first handpiece 1 driven by a compressed-air turbine and a second handpiece 2 driven by a miniature D.C. electric motor 3. Connected to the housing by a multiduct hose is a foot control device 6 comprising first lever 19 and second lever 20, the levers being so arranged that depression of the second lever will automatically depress the first lever. On withdrawal of a handpiece from its holder, a rotary slide valve 12 is automatically displaced to one of two end positions thereby to interconnect the handpiece with a source of compressed air which passes via conduit 5, Conduit 5', valve 9 (controlled by the first lever of the foot control device), conduit 7', conduit 7 and thence either via non-return valve 10, lubricator 11 and the rotary slide valve to the first handpiece or via conduit 13 and the rotary slide valve to the second handpiece. Compressed air also may pass from point 14 via valve 15 (controlled by the second lever of the foot control device), conduit 8' and conduit 8 to a switch 16 which controls a valve 17 located in a conduit 18 which supplies water to the first and second handpieces via respective conduits 27 and 26 in which conduits are located respective valves 25 and 24 which are connected mechanically to the rotary slide valve; the switch includes a diaphragm 28, one side of which is subject to the pressure of the compressed air, and a chamber 29 which is supplied with water via conduit 30. The water is used for water or spray cooling or cleaning of a zone, for example a tooth, being treated; air for forming a spray is supplied to the second handpiece via conduit 21, valve 22, the throughput of which valve is adjustable by rotary cock 22', and ever-open small-throughput by-pass valve 23. Mains terminal lines 32 and 33 supply electricity via a mains connection assembly 31, lines 34 and 35, a variable gain and power amplifier 38, and lines 39 and 40 to the motor of the second handpiece, the speed of which motor is regulatable by potentiometer 41 controlled by knob 42; the electric circuit is closed by contact switch 36 which is operated by diaphragm switch 37 controlled by compressed air supplied via top conduit 13'. Container 43 serves to provide pressure equilibrium in the compressedair conduit system which system further includes an oil separator 45 in the return air conduit 44 leading from the first handpiece. Figure 2 (not shown) illustrates diagramatically a modified foot control device which comprises two independently operable levers. The construction of the two foot control devices is illustrated in detail in Figures 5 and 6 (not shown). Figures 3 and 4 (not shown) illustrate in detail the construction of the dental apparatus unit, in particular the construction of the rotary slide valve and the arrangement whereby compressed air is supplied to a handpiece when the handpiece is withdrawn from its holder; as illustrated, each hose carrying either the compressed air and water supply conduits to the first handpiece or the compressed air and water supply conduits and the electric supply lines to the second handpiece passes over guide rollers mounted on a rockable lever to which is articulated a linkage for controlling the valve system, each handpiece being withdrawn from its holder in opposition to spring force.