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United States Patent | 4,194,289 |
Neri | March 25, 1980 |
A pneumatically operated system for controlling the supply of water and/or water and air simultaneously to an air turbine-type dental handpiece, either to only drive the handpiece or drive it and simultaneously provide a spray. Two foot-actuated valves respectively controlling the supply of air to a handpiece are connected to a source of air under pressure and are respectively connected to a compound servo-control valve including a spool operable in a housing between various inlet and outlet ports for air which, when one foot-actuated valve is opened, will cause the spool to move from an initially inoperative position to afford delivery of drive air only to the handpiece and when the second foot-actuated valve is opened, additional air is by-passed at the same spool setting from one part of the housing to another part containing a normally closed water valve connected to water under pressure and opened by said additional air which actuates a small piston that engages said water valve to open it. The handpiece is supported in a holder by which the spool is maintained in said inoperative position. Springs restore the spool and small piston to their initial inoperative positions.
Inventors: | Neri; Vincenzo (Turin, IT) |
Appl. No.: | 05/944,223 |
Filed: | September 20, 1978 |
Sep 22, 1977 [IT] | 69093 A/77 | |||
Current U.S. Class: | 433/101 |
Current International Class: | A61C 1/00 (20060101); A61C 019/02 () |
Field of Search: | 32/22 137/637.1,87 |
3755899 | September 1973 | Betush |
3875958 | April 1975 | Miller |
3924660 | December 1975 | Woodhams |
4069587 | January 1978 | Peralta |
Progressive Machine Products Co., 2209 Federal Ave., Los Angeles, Calif. 90064, "Proma 360", Systems and Vertifour, 3 pp., Dec. 77.. |