With a combination lock, a sequence of numbers or sometimes symbols is used to gain entry. Depending on the exact type of lock, the sequence is entered using just one dial that rotates to interact with several discs or a set of rotating discs that interact with the locking mechanism. However, for modern locks, rotating discs also work in conjunction with a mechanical or electronic keypad.
Where Are Combination Locks Used?
Simpler combination locks are found on suitcases and bicycle locks, but this type of locking mechanism is also beneficial for high-security safes and gun cabinets. Because entry is gained without the use of keys, the only way a safe will open is by moving the numbers or symbols in the right sequential pattern.
Today, it is common for a homeowner to have a personal safe. However, safes are more commonly used in businesses. Regardless, the goal is to have the best combination lock on the safe possible, protecting valuable documents and personal items inside.
Understanding the Way Combinations Locks Work
- Typically, a combination lock is designed with a wheel pack, which consists of a set of wheels designed to work with one another. These wheel packs are all made using the same basic principal. The lock includes a combination dial attached to a spindle. Within the lock, the spindle works by going through several wheels, as well as a drive cam.
- The amount of numbers in the combination determines the number of wheels in the wheel pack. In other words, each number uses one wheel. When the dial on the combination safe is turned, the drive cam also turns by the spindle. On the drive cam is a drive pin; as the cam begins to turn, the pin will make contact with a tiny tab on the adjacent wheel, which is referred to as the wheel fly, is found on the sides of each wheel.
- From there, the drive pin spins the first wheel until it makes contact with the adjacent wheel. This process continues until all of the wheels in the wheel pack are spinning. Every spindle wheel is also designed with a cutout notch; once the correct combination has been dialed, the wheels and coordinating notches line up.
- The fence prevents the door from opening; the fence is a small metal bar that attaches to the safe’s exterior lever. The fence rests on the wheels, thereby blocking the bolt’s path and keeping the door safely closed. Unless the correct combination is dialed, the fence will not budge. The aligned notches create a gap into which the fence drops due to its weight. At that point, the bolt can slide freely and the door can open.
Electronic combination locks work on the same principal; however, rather than the process being manual, it is automated. As you can imagine, electronic combination locks are easier to use and ultimately the better choice. However, they are more expensive and a professional locksmith must install them.