A cylindrical key operated variable code lock provides a shell having a cylindrical inner surface and an orifice for accepting a key. The key may be generally cylindrical in shape carrying a number of lugs thereon that are rotationally variable. The drum is normally rotationally fixed relative to the...http://www.google.se/patents/US5209088?utm_source=gb-gplus-sharePatent US5209088 - Changeable code lock
