Abstract: A drive for a weapon is provided, wherein rotational motion of a motor is converted to a forward or reverse motion of the breech in a simple manner using the Scotch yoke principle. In order to allow rest periods of the breech in the end positions, the crank radius is defined by a control cam, which changes when the crank is rotated. The hinge pin of the crank may be externally driven via a pinion shaft. A yoke pin is arranged in a groove of the crank so as to be radially displaceable and carries the breech carrier or the breech in a groove extending transversely to the direction of fire via a sliding block. Two rollers are arranged on the crank pin and run in control cams in the weapon or crank housing. The control cam is subdivided into different sectors/sections, thereby achieving the desired motion of the breech.

Abstract: A drive for a breech/breech carrier renders it axially adjustable relative to a weapon barrel. The drive includes a motor, two engaging cams mounted on a chain arranged below the breech and guided around two sprocket wheels. A slide is mounted in a guide at the bottom of the breech/breech carrier so as to move at a right angle to the direction of fire, with a groove extending over its entire width. The respective engaging cam entrains the breech in forward motion relative to the direction of fire, or in reverse motion, once the shot is fired, and transports the breech forwards, is displaced from the groove, and moves backwards without the breech, thereby allowing breech rest periods in a forward position. During firing, the slide moves, whereas it remains stationary when no shot is fired so no further engaging cam can entrain the breech backwards.