| 摘要 |
An obturator (210, 310, 410) is provided for a projectile (10) launched from a gun barrel (110). The projectile has a mid-body annular groove (22) that includes a shaped surface (26, 30). The obturator includes an annular ring having an inner surface (216, 416) in contact with the shaped surface of the annular groove of the projectile. The annular ring further includes an outer surface (214, 414). When the projectile is in the gun barrel, the outer surface of the annular ring contacts an inner surface (142) of a bore (140) of the gun barrel. The radial distance between the inner surface and the outer surface of the annular ring substantially equals or exceeds the radial distance between the shaped surface of the annular groove and the inner surface of the bore of the gun barrel at at least one point when the projectile is positioned in the barrel. The aft surface (218, 418) may comprise a curved or linearly tapering surface that directs the charges gases created when the projectile is launched such that the gases expand or inflate the obturator. The inner surface further includes a ramp surface (220, 320, 420) allowing the obturator to slide up a ramp (30) of the shaped surface inside the annular groove and the expand. This feature restricts a flow of charge gases from an aft end (18) of the projectile to a forward end (16) of the projectile when the projectile is launched from the gun barrel.
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