| 摘要 |
PROBLEM TO BE SOLVED: To simplify the structure by forming a space between the rear end of the gunbarrel and a part for holding a next bullet and providing a pressure difference valve in the space thereby eliminating the pressure difference valve in a working barrel. SOLUTION: A gunbarrel 12 has inclining rear end and a tubular space 13 is provided between the rear end and a part 36 for holding a next bullet 70 continuous thereto. A pressure difference valve 14 for opening/closing the rear end part of the gunbarrel 12 is disposed in the space 13. The pressure difference valve 14 is normally opened under curved state by an elastic material in a rubber tower and it is closed when the pressure in the forward gunbarrel 12 drops by a specified level or more than the pressure in the space 13. Since the pressure difference valve 14 is not required in the working barrel 33 but it can be set in the wide space 13, structure and installation of the pressure difference valve 14 can be simplified significantly. |
