Locks are divided into 3 categories according to the closing pin:
- Lock with pin or bolt
Manual locks with opening on both sides, the pin remains inside the lock until locking by the key.
- Lock with latch mechanism
Pin remains outside the lock body. Its triangular shape and the internal spring of the mechanism allow the pin to fall automatically under closing again to exit and lock the door. In this case the door can be opened by a handle or knob: turning the handle pin falls opening is possible, to lock the door key turn is necessary.
- Lock with roller mechanism
This lock type works in the same way of latch lock but allows the opening on both sides thanks to the oval shape of the pin.
The scheme here above represents the types of pin and the different openings.