| 摘要 |
A medical bevel needle (1) having an open bevel end surface 3 is provided, wherein cutting edges (9) that linearly extend from the front end of the front-end portion (2) on the right and left sides diagonally rearwardly are formed either by right and left front ground faces (5) crossing the open bevel end surface (3) or by right and left front ground faces (5) crossing the external circumferential surface (4) of the bevel needle (1), and the maximum lateral width between the cutting edges is limited by right and left rear ground surfaces (6). When the needle axis is held horizontal with the open bevel end surface (3) facing upward, the right and left front ground surfaces (5) cross each other at the front end of the front-end portion (2), and extend diagonally rearwardly and symmetrically with respect to a vertical plane containing the needle axis, where the right and left rear ground surfaces (6), respectively succeed the right and left front ground surfaces (5) at a longitudinal position where the lateral width between the right and left front ground surfaces (5) reaches a specified length, e.g., a length equal to the radius of the bevel needle, and extend diagonally rearwardly and symmetrically with respect to the vertical plane at an angle smaller than the angle of the right and left front ground surfaces (5) with respect to the vertical plane. The right and left rear ground surfaces (6) respectively have a tilt angle of 5 pi /12 to pi /2 radians (75 to 90 degrees) with respect to the horizontal plane. <IMAGE> |
