The working of a combination lock is not that easy. It involves the proper working of several parts inside and outside the device, which include the following:

• Dial
• Spindle
• Drive Cam
• Drive Pin
• Wheel Pack
• Wheel Fly
• Notch
• Fence

A combination lock works in the same manner as a lever mechanism inside traditional key locks. With both types of locks, there are tumblers inside that are to align, which causes the fence inside to activate. The aligning of these tumblers allows the bolt to open, causing the lock to open. The difference between the two locks is that the combination lock doesn’t require a key, but a use of numbers or letters.

When it comes to the outside of the lock, the dials are turned around four times in the initial direction to help engage the wheels. This is so that as the dial turns, the wheels are able to turn smoothly, as well. This ensures that the lock turns smoothly and you have the ability to open it without any hassle.

When you turn the dial over to the first number and stop, the corresponding wheel will be aligned with the fence. When you turn the dial in the other direction, the wheel will stay in place and disengage with the fence. When you stop the dial at the next number, the second wheel will be aligned, and turning the dial in the opposite direction also disengages it. This process is repeated for additional numbers in the combination. Once all the numbers are set, the drive cam retracts to the bolt on the lever, causing the lock to open.

The dial is attached to a spindle inside the lock. When the dial turns, the spindle does as well. The spindle is attached to the drive cam, which is attached to a drive pin. When the drive cam turns, the pin rotates. At one point in which the dial turns, the pin will come into contact with a wheel fly on a wheel once you stop on the correct number in your combination.

When the first wheel starts to spin, it causes a chain reaction when it touches another wheel. When all wheels are spinning, it creates a phenomenon known as “picking the wheels up”.

The notch on each wheel is used to determine if the combination is correct or incorrect. The right combination will lead to all the notches falling into place, causing a gap in the padlock, leaving room for the bolt to open. If the fence does not go inside the gap created by the notches, the lock will not unlock.