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Combination Locking Mechanism: It’s All In The Code

Combination locks (the product of a Combination Locking Mechanism)  are a type of padlocks that have been around since the ancient Roman times. The earliest types of such locks were comprised of a small box with several dials instead of keyholes. This led to the development of modern combination locks that use a wheel pack by a German locksmith known as Joseph Loch in 1878. Basically, such locks use a sequence or permutation of symbols or numbers to open the lock.

In most cases, these sequences or permutations are entered using a set of several rotating discs for stand-alone and mortise locks or electronic variations of cylinders that operate electrically. Nonetheless, combination locking mechanism is similar for a majority of these locks.

These locks are keyless and all you need to have to access your safe is the correct combination. Although these locks were originally developed for use in cars, they have been successfully modified for use in safes at home for jewelry and guns and also by big organizations to safeguard crucial information.

How is a combination lock is designed to work

Combination Locking Mechanism DismantledAs mentioned earlier, modern combination locks operate using a wheel pack that is well designed to work together based on the same principle. For instance, a typical combination lock has a combination dial that’s connected to a spindle that runs through numerous wheels and a drive cam located inside the lock. Usually, the number of wheels in a wheel pack used in such locks entirely depend on the number of symbols or numbers used in the combination, for example, each number or symbol has its own wheel.

Combination locking Mechanism Design

To enter your combination, you must rotate the spindle that turns the drive cam with a drive pin attached to it. The drive pin, in due course, makes contact with a small tab attached to an adjacent wheel known as the wheel fly as the drive cam rotates. Basically, each wheel has a wheel fly on each of its sides.

As you rotate the spindle while attempting to unlock the lock, the drive spins the first wheel before it makes contact with the wheel adjacent to it. This spinning continues until all the wheels rotate in a manner well known as picking up the wheels. Each wheel attached to the spindle has a notch cut into it. As a matter of fact, when you dial the right combination all the wheels and their notches line up seamlessly. This results in the formation of a gap that allows the hasp of the lock to release and hence the bolt can slide freely rendering the safe accessible.

To prevent entry by unauthorized individuals who enter the wrong combination or would like to access the safe without dialing the combination, a small metal bar called the fence is attached to the unlocking lever. The fence does this by resting on the wheels and hence block the path of the bolt that secures your safe.


One of the greatest advantages of this type of a locking system for your safe is the fact that it’s keyless and hence you don’t have to worry about losing your key. Also, it means that you won’t need to store a spare key for other authorized individuals to access your safe at your discretion without the need to make copies of a key.
Also, with a combination locking system in place, you can make your safe more secure by setting up an alarm system that will let you know when and how other people attempted accessing it. This gives you a good idea on how secure your safe is.


While there are several benefits associated with any keyless locking system, it also comes with major drawbacks including the fact that an intruder may gain access to your safe by guessing or hacking the combination.
Also, it is possible for one to forget the code, especially for people with memory issues like the elderly. Combination locks that are usually powered by electricity might not function in the case of a power failure.

As much as combination locks provide top notch security for your safe, it is very important that you shouldn’t use numerical combinations based on your birth dates or any other non-unique codes that can be easily guessed by intruders. Also, choose a combination that you can easily remember and keep it a secret.


Combination locking mechanism are a great option for anyone looking for a secure locking mechanism. The probability of children or unauthorized individual guessing the pass code is very small. So you can rest assured that your family will be protected.

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