Combination locks are use to secure safes and unlike most locks that need a key combination locks rely on codes.
Combination Lock Parts
Dial
The dial is a wheel with numbers in it that turns in order to insert a certain combination.
Spindle
The spindle is a shaft inside the lock that connects to the dial and when you the dial is turning it moves the spindle.
Disc Wheels
Usually there are 3 wheels inside the lock positioned one on top of each other and when they are lined up correctly it unlocks the mechanism.
Notches
Each wheel has a notch that needs to align with the other notches to let the lock open.
There are 3 types of combination locks the most common type is a single-dial which is like the ones you use on a locker. The second is a multi-dial and it has several dials with set of numbers on each. The third one is an electronic and instead of turning a dial you tap the combination code on the keypad.
How does it work?
When turning the dial the spindle rotates the wheels inside the lock. Each wheel react to a specific number in the combination and when the correct sequence goes on the wheels start lining up. When you reach the first number in the combination it means that the wheel is aligned with the notch which creates a small gap in the mechanism. Then you turn the dial in the opposite direction which moves only the second wheel while the first wheel stays in place and when you reach the second number it lines up with the first one. Now repeat this process for the third wheel, turn in to the opposite direction till you get the right number and get it lined up with the other 2 wheels. When all the notches align, a small lever called a “pawl,” unlocks the the door mechanism, letting you open the safe.
