| 摘要 |
An air rifle having a firing mechanism (12) which comprises a variable volume gas chamber (52) behind a piston (28) which moves within an outer cylinder (26) in front of a rear cylinder (36). The gas chamber (52) is defined between the piston and the rear cylinder and is sealingly closed. When the rifle is cocked, the piston is latched in its most rearward position in which the gas in the chamber (52) is most highly compressed. The trigger releases the piston latch, causing the piston to be driven forward as the gas expands in the variable volume chamber compressing the air in the outer cylinder (26) in front of the piston (28) until it exceeds a threshold which fires the pellet out of the breech. The semi-permanent charge of gas in the chamber (52) thus constitutes a pneumatic spring. A safety device is provided to relieve pressure in the chamber (52) before the firing mechanism can be dismantled. |
