Abstract: A pin tumbler lock is provided with one or more additional chambers for housing a secondary locking member for engagement with a portion of a key. The invention also provides a lock system comprising a plurality of locks, each lock including two chambers. The lock system has a potential of N chamber positions to provide a substantial increase in the number of effective unique pin tumbler combinations that can be produced on the same key section or profile by allowing the same pin tumbler combination to be repeated with different locations of these additional chambers.

Abstract: The invention provides a pick-resistant locking mechanism with wafer tumblers, sidebars and an interchangeable cylinder that allows re-keying of the lock. The sidebars have projections with beveled sides that engage with cavities in the lock shell when rotational torque is applied to the lock in the absence of the correct key. A sidebar of the lock contacts two, nonadjacent wafer tumblers. The wafer tumblers have indentations that engage cavities in the lock shell when rotational torque is applied during picking of the lock. Tolerance between sidebars and the lock shell is less than the tolerance between tumblers and the lock shell. The tumbler springs are not accessible from the keyway of the lock and are more powerful than the sidebar springs.

Abstract: A pin tumbler lock is provided with one or more additional chambers for housing a secondary locking member for engagement with a portion of a key. The invention also provides a lock system comprising a plurality of locks, each lock including two chambers. The lock system has a potential of N chamber positions to provide a substantial increase in the number of effective unique pin tumbler combinations that can be produced on the same key section or profile by allowing the same pin tumbler combination to be repeated with different locations of these additional chambers.