| 摘要 |
<p>A head assembly for attaching to a dental instrument has a body, a rotary shaft with a pinion thereon, at least one retractable catch latching lever and a retractable catch. The rotary shaft has a central bore suitable for receiving a shank of the dental instrument therein. The latching lever has a peg engageable with an annular latching groove of the shank of the dental instrument. The catch has a positioning plane coinciding with the drive flat of the instrument. The body has a circular opening closed off by a push button cooperative with the rotary shaft so as to release the shank of the dental instrument.</p> |
