| 摘要 |
<p>The invention concerns a security device comprising a stop member for a rotary drilling instrument used in particular in dental surgery, said stop member capable of being positioned at a desired depth of drilling and preventing said depth from being exceeded. The two elements drilling instrument (10, 10A) and the stop member (20; 30; 20A; 30A) comprise coupling means directly or indirectly linking them together and co-operating means capable of transforming their movement, such that when the device is operating, the drilling instrument (10, 10A) is retracted rearwards relative to the drilling direction and to the position of the stop member under the action of said means when the front part (23; 33; 23A; 33A) of the stop member comes in contact with a neighbouring surface (9). The co-operating means preferably consist of a screw-nut system, the direction of the thread(s) of said system and the rotating direction of the drill being opposite. A device comprising a gauge (50) containing a piston (55) enables to pre-calibrate and store the desired drilling depth.</p> |
