| 摘要 |
An air gun of the break-barrel type has a spring-urged piston working in a bore of a cylinder. The piston has two axially spaced latched cocking positions in the cylinder; an intermediate position in which the spring is only partially compressed, and a fully cocked position in which the spring is fully compressed. The piston is held in each of its latched positions by the co-operation, in turn, of a sear with a one of a pair of axially spaced grooves in the piston. Initial downward swivelling of the barrel causes a cocking bar pivotally connected to the barrel to engage in the rearward groove and force the piston backwards to its intermediate position. The gun can then be fired with reduced power or alternatively a second cocking stroke performed in which the cocking bar engages in the forward groove and urges the piston to its fully cocked position. Instead of having a breaking breech, the gun may operate by a cocking lever. The piston may have more than one latch intermediate position in the bore. |
