Without turning the inside needle, the inside needle advance retreat possible unlocking state, advance retreat impossible lock state is changed with simple operation vis-a-vis the outside needle. The front part of the tubular inside needle basic end which is provided in the basic edge of the inside needle is installed in the rear end of the tubular adapter, the tubular outside needle basic end which from the point of the adapter is provided in the outside needle basic edge is inserted, the point of the inside needle is made to extend from the point of the outside needle. The groove of plural lap directions in parallel in the underside of the outside needle basic end, it forms, from opening which is provided in the surface, the aforementioned outside needle basic end passes to the adapter, when it loads the regulation board which possesses the hole, in the underside of the hole, extends to upward and the groove of the aforementioned outside needle basic end it provides the projection which engages, pushes down the regulation board the groove of the outside needle basic end and engagement of projection of the regulation board coming off, when the inside needle it becomes advance retreat possible unlocking state vis-a-vis the outside needle, cancels the depression the regulation board rises,The groove of the outside needle basic end and projection of the regulation board engaging, it becomes lock state.内針を回転させることなく、簡単な動作で内針が外針に対して前進・後退可能なアンロック状態と、前進・後退不能なロック状態を切り替える。内針の基端に設けた筒状の内針基端部の前部を筒状のアダプタの後端部に取り付け、アダプタの先端から外針基端に設けた筒状の外針基端部を挿入し、外針の先端から内針の先端を突出させる。外針基端部の下面に複数の周方向の溝を並列して形成し、アダプタには、その上面に設けた開口から、前記外針基端部が挿通される挿通孔を有する規制板を装入し、挿通孔の下面に、上方に突出し前記外針基端部の溝と係合する突起を設け、規制板を押し下げると外針基端部の溝と規制板の突起の係合が外れて内針が外針に対して前進・後退可能なアンロック状態となり、押し下げを解除すると規制板が上昇し、外針基端部の溝と規制板の突起が係合してロック状態となる。
