| 摘要 |
PROBLEM TO BE SOLVED: To substantially prevent the dislodgment of a plastic member from a columnar member of the handle of a dental handpiece formed by mounting the plastic member to be formed as a core material and a handle into the metallic columnar member. SOLUTION: The plastic member 2 is molded between the metallic hollow columnar member 1 opened at both ends and the handle 3 mounted therein and is formed as the core material together with the handle 3. The inner peripheral surface of the columnar member 1 is provided with plural pieces of recesses 4 along the axial direction thereof. The molded plastic member 2 is pressed by the handle 3 and is strongly intruded into the recess 4 within the columnar member 1. The plastic member 2 is hardly disengaged from the columnar member 1 in spite of repetitive use. |
