| 摘要 |
The instrument has a handle (3) placed at an end opposite to an active part. The handle has a sprocket (4) engaging directly with a driving unit located upstream of a head of a hand piece. The sprocket is made from a flat metal part integral with an axis of the active part and has four openings to allow circulation of plastic material at the time of molding phase and to ensure the connection of the sprocket on the axis. |
