Abstract: A lock with plate-shaped tumblers opened or closed by a cylindrical key bar composed of a cylindrical key bar having annular extending grooves corresponding to the tumblers, cylindrical plug, lock body, protecting ring, protecting plate and several plate-shaped tumblers having square or oval holes therethrough arranged in single row, double rows or cross rows. The tumblers are arranged within the plug by single row, double row or cross row. When the lock is in the closed state, the tumblers are spring biased into a first set of obstructing grooves in the lock body. When the key bar is first inserted into the lock through the tumbler holes, the tumblers are pushed into a second set of grooves in the lock opposing the first set. When the key is turned, the tumblers fall into the corresponding grooves and upon further turning the sides of the grooves engage the tumblers turning the plug and opening the lock.

Abstract: A cylindrical lock with tumbler and driver pins opened or closed by a cylindrical key in which a cylindrical plug is provided with one row or several rows of ".phi."-shaped tumbler pins and the lock body is provided with corresponding driver pins of diversified shapes in equivalent rows. When the lock is closed, the driver pins brake the cylindrical plug at the lock body and thus cannot be rotated. In order to open the lock, the cylindrical key bar is inserted in the key hole of the plug. The key bar is formed with grooves of suitable angle. When the cylindrical key bar is rotated in the key hole, the grooves on the key bar will back up the ".phi."-shaped tumbler pins to the periphery of the plug while pushing the driver pins from the plug into said lock body to make the plug free from said lock body. The cylindrical key bar with special designed angled grooves will apply pressure to the ".phi."-shaped tumbler pins engaging with said plug so as to actuate the lock latch.