| 摘要 |
The water and air supplies to a dental drill are controlled by two valves respectively. The water and air supplies are connected to the drill from a side outlet (9) communicating with an upper chamber (8) above a diaphragm (4) forced downwards by a helical spring (6). A boss (5) in the middle of the diaphragm supports a rod (7) which operates a ball valve (15) on top of the housing. When lifted, this permits air or water to pass from a small chamber with a side entry tube (16) into the upper chamber. The lower chamber (3) has a connection (2) for a control unit connected to the compressed air supply, which ensures that a constant pressure is maintained. |
