GB853638A - Improvements in dental engine stands for supporting a dental engine of the type comprising a hand-piece and a pressure fluid operated motor carried by said hand-piece - Google Patents

Abstract

853,638 Dental stands. ATLAS COPCO A. B. Sept. 8, 1958 [Sept. 24, 1957], No. 28769/58. Class 81 (2) A dental handpiece of the fluid-driven type is carried on a stand and the arrangement is such that power is supplied to the tool only when the handpiece has been lifted from the stand. The invention is described with reference to the type of handpiece 7 which encloses an air-driven turbine and this, when not in use, is supported at one end of a lever 62. When the handpiece is lifted, the lever 62 is raised by a spring 64 and, through a rod 58, lifts a valve member 44 off its seating to allow air to flow to the pipe 57 and so to the turbine. Compressed air received through a pipe 10 is reduced in pressure on passing through a pressure control valve 14, controlled by an adjustable spring-loaded diaphragm 21 and then passes through the tubing 39 to the lever actuated valve 44 and so to a manually controlled check valve 51 to the handpiece. The manual valve 51 can be set as required and, thereafter, the supply of compressed air is dependent on the lifting and replacing of the handpiece on the lever 62. The opening of the valve 44 causes a reduction in pressure in the control valve chamber 20, with a resultant inward movement of the diaphragm 21, and this is communicated through the valve stem 15 to a micro-switch 31 which causes the water spray pump to be switched on, to supply water through a tube 79. This is then directed by a slide valve 70 to either of two tubes 80, 82, to supply water to whichever of the two handpieces is in use, the changeover of the valve 70 being effected by air pressure acting on the appropriate side of a piston 74 and supplied from the appropriate air line leading to the handpiece. Specification 785,109 is referred to.