| 摘要 |
A gas cartridge introduced into the housing of the invention is punctured by a pin moved by an arm designed to show through a window whether the cartridge is full or empty. A pulling on a tab rotates the arm to action, in puncturing the cartridge and a spring then locks the visual display in position. The pin is provided with a cone-shaped head which prevents any re-arming of the arm from changing the display to show that the cartridge is full, when in fact the cartridge has been spent. |
