An annular portion (first loose fitting portion) is provided at the distal end of the driving wire inserted through the sheath, and a U-shaped portion (second loosely fitting portion) of the connecting hook (opening and closing portion) And the connecting hook was made to oscillate with respect to the driving wire.シースに挿通された駆動ワイヤの遠位端に円環部(第1遊嵌部)を設け、連結フック(開閉部)のU字状部(第2遊嵌部)を該円環部に遊嵌させ、連結フックを駆動ワイヤに対して首振り可能にした。
