| 摘要 |
PROBLEM TO BE SOLVED: To easily bring an outer periphery of a barrel portion of a barrel and an outer periphery of a convergent nose mouth end into coincidence with an axis by inserting the barrel portion of the mouth end into an inner hole of a barrel, and engaging a stepped portion of a locking protrusion with that of a locking window to fix the mouth end to the barrel portion. SOLUTION: A tapered portion and a collar portion are provided on a front end of a convergent nose mouth end 25, and a barrel portion 25b is provided rear of the collar. A rib-like locking protrusion 25c is formed on an outer periphery of the portion 25b in the state corresponding to a locking window. The protrusion 25b has an arrowhead-like tapered portion directed rearward at its rear end, and a stepped portion is formed on an opposite surface of the arrowhead-like state. The outer periphery of a front barrel 24 is covered with a grip 27 in the state that a rib and a groove are opposed. The portion 25b of the mouth end 25 is inserted into an inner hole of a front end of the front barrel. A stepped portion of a locking protrusion 25c is engaged with a stepped portion of the window by utilizing an elastic deformation, and the end 25 is fixed to a front end 24. Then, front and rear ends of the grip 21 are axially narrowed between the collar portions. |
