Cylinder protective system

A cylinder lock providing a safeguard against pull-out of a cylinder of the lock from its housing by a pull-out force applied to the cylinder with a foreign object forcefully entered into a keyway, the cylinder lock comprising:

• a housing formed with a cylindrical bore defining an inner surface;
• and
• a cylinder within said bore carrying locking elements movable to locking and unlocking positions with respect to said housing;
• said cylinder having an outer diameter equal to the diameter of said bore so as to be rotatable when the locking elements are in unlocking position with respect to said housing;
• said cylinder being formed with a keyway for receiving a proper key in order to move the locking elements to their locking and unlocking positions with respect to said housing, the keyway sized for receiving the proper key;
• characterized in that said cylinder further comprises at least one insert from hardened material movably disposed in at least one groove or hole formed through a surface of the cylinder and extending toward the keyway, wherein the at least one insert is sized to be contained between the keyway and the inner surface defined by the cylindrical bore formed in the housing and is operative to slide out of the at least one groove or hole toward the inner surface defined by the cylindrical bore formed in the housing and forcibly engage or gouge the inner surface defined by the cylindrical bore formed in the housing only in response to forceful entry of a foreign object having a diameter greater than the size of the keyway into the keyway.