PROBLEM TO BE SOLVED: To achieve high-stability cutting with high cutting efficiency.SOLUTION: This cutting instrument includes: an elongated member including a tubular part 105 and a shaft-like part 101 inserted in the tubular part 105 a blade 201 which has two edges, is provided at one end of the elongated member, and can turn between a storage position wherein the blade 201 is stored inside the elongated member and a projection position wherein the two edges are projected outside the elongated member operation parts 102-104 provided at the other end of the elongated member, and relatively moving the tubular part 105 and the shaft-like part 101 and a movement mechanism changing the relative movement of the tubular part 105 and the shaft-like part 101 generated by operation of the operation parts 102-104 into a turn of the blade between the storage position and the projection position. In a state that the two edges of the blade 201 project on both sides of the tubular part 105, the blade 201 moves toward the operation parts while rotating as a whole, so that the cutting instrument bores a hole having a diameter larger than the outside diameter of the tubular part 105.COPYRIGHT: (C)2013,JPO&INPIT【課題】切削効率が高く且つ、安定性の高い切削を実現すること。【解決手段】筒状部105と、該筒状部105に挿入された軸状部101とを含む長尺部材と、2つの刃を有し、長尺部材の一端に設けられて、長尺部材の内部に収容された収容位置と長尺部材の外側に2つの刃を突出させた突出位置との間で回動可能なブレード201と、長尺部材の他端に設けられ、筒状部105と軸状部101とを相対的に移動させる操作部102~104と、操作部102~104の操作によって生じた筒状部105と軸状部101との相対的な移動を、収容位置と突出位置との間のブレードの回動に変更する運動機構と、を含み、ブレード201の2つの刃が筒状部105の両側に突出した状態で、全体として回転しつつ操作部側へ移動することにより、筒状部105の外径よりも大きな径の穴を穿孔する切削工具。【選択図】 図3
