Patent ID: 7159502

Claim:
A sliding block breech mechanism for a cannon, comprising: a breach ring arranged at a rear end of a cannon barrel and defining a cavity; and a sliding breech block that slides perpendicularly to a longitudinal axis of the cannon barrel in the cavity of the breech ring, the sliding breech block having at least two laterally projecting lugs, which are arranged one behind the other as viewed in the direction of the longitudinal axis of the cannon barrel and engage corresponding roots of walls of the cavity of the breech ring, so that when the cannon is fired, pressure flanks of the lugs of the sliding breech block, which face away from the cannon barrel and are designed as contact surfaces, are supported on corresponding pressure flanks of the roots of the walls of the breech ring, the lugs including first lugs and second lugs, the first lugs being closer to the cannon barrel than the second lugs, the pressure flanks of the first lugs of the sliding breech block and the pressure flanks of the corresponding first roots of the walls both having a positive angle of inclination, and the pressure flanks of the second lugs of the sliding breech block and the pressure flanks of corresponding second roots of the walls both having a negative angle of inclination.