Straight breech for an automatic gun barrel weapon, in particular a machine cannon

摘要

An improved ammunition feed and guide mechanism for an automatic gun barrel weapon such as an automatic machine cannon. This mechanism includes a breech mechanism mounted in a housing. The breech mechanism includes a breech body driven by a pair of rollers rotatably mounted in the housing parallel to the middle longitudinal axis of the housing. Each roller has a driving ramp disposed on its periphery and the breech body is provided with a pair of roller bearings respectively engaging the driving ramps of the rollers so that the breech body is linearly reciprocated between loading and firing positions via the rotation of the rollers and the engagement of the roller bearings in the driving ramps thereof. The pair of rollers are driven by means independent of the propulsion energy of the fired projectiles. When the breech body is in the firing position, the roller bearings and driving ramps are maintained substantially free from the influence of the axially acting recoil forces brought to bear on the breech body during firing.