What Is a Combination Lock, and How Does It Work?

What Is a Combination Lock, and How Does It Work?

There are numerous types of locking mechanism available. One of the most popular options is the combination lock. To determine if this is the right lock for your needs, it is helpful to learn more about what this lock is and how it works.

What Is a Combination Lock?

A combination lock is designed to dislodge and open following the entry of a specific sequence of symbols. Typically, numerical symbols are used, but there are combination locks that use letters and other symbols for forming the sequence as well. The exact sequence used depends on the type of combination lock, such as single dial, multiple dial, or electronic. Single and multiple dial combination locks are most often used.

  • Single Dial – Padlocks and safes are commonly used in conjunction with this type of combination lock. This combination lock is designed with parallel discs that are indented and made to correspond to a certain symbol and rotation pattern. Once the correct sequence and pattern are entered, the indentions line up, which then allows the lock to open.
  • Multiple Dial – For this combination lock, there is a toothed pin, as well as numerous notched discs that rotate. While this lock offers good security, it is not as protective as the single dial and electronic combination lock, since mechanical irregularities exist that can be compromised relatively easy.

Even though a combination lock has slight flaws pertaining to security, for the most part, this is an extremely good choice. In addition to security, one of the biggest advantages of a combination lock is that it can be used to secure almost anything. However, this type of lock is commonly used to secure a bike, safe, or briefcase.

How a Combination Lock Works

The majority of combination locks sold use a set of wheels that work cohesively to determine the combination. Known as a wheel pack, the principal is much the same regardless of the type of combination lock. There is also a combination dial attached to an internal spindle that runs through a number of wheels, as well as a drive cam.

The quantity of numbers in the sequence is what determines the number of wheels, with there being one wheel per number. Once the dial is turned, the drive cam with a drive pin attached is turned by the spindle. As the cam turns, the pin makes contact with a small tab on the wheel fly, which is on each side of the wheel.

When turning a combination lock, the drive pin moves past the first wheel, eventually connecting with the adjacent wheel. This process continues to the point that all wheels spin. Each wheel also has a notch so that once the correct combination is dialed, the wheels and notches perfectly align.

A combination lock used on a safe has a fence, which is a tiny metal bar that attaches to a lever to prevent the lock from being opened unless the right combination is used. For a padlock, once all the wheels are properly aligned, the notches align to create a gap that allows the lock’s hasp to release.

Leave a Reply