| 摘要 |
<p>A gas cartridge (56) introduced into the housing (12) of the invention is punctured by a pin (46) moved by an arm (32) designed to show through a window (26) whether the cartridge is full or empty. Pulling on a tab (38) rotates the arm to action, in puncturing the cartridge, and a spring (66) then locks the visual display in position. The pin (46) is provided with a cone-shaped head (50) which prevents any re-arming of the arm (32) from changing the display to show that the cartridge is full, when in fact the cartridge has been spent.</p> |
