A rim lock is very common in many houses. In fact, I think you might have come across a rim lock without knowing. A rim lock not only has a special design, but also has a wonderful history for you to discover. A rim lock is an old lock and its design hasn’t changed much over the years. Usually, you can find a rim lock in an old building. A rim lock is fixed to the surface of the door, which is not suitable for entry doors. Most of rim locks were originally made of cast iron, though replicas are made of brass, nickel and iron. The word rim lock refers to its installation way, that is, surface mounted installation. A sliding latch or deadlock is used as the locking mechanism of the rim lock.
The sliding latch is spring loaded and pressure operated. When pressure is applied, the latch is retracted. When pressure is not applied, the latch is extended. Combine with a sliding latch, most rim locks use knobs or handles. A key is used for a deadlock bolt.
There are two kinds of rim locks, rim sash locks and rim latches. A key is used to disengage and engage the rim lock or throw and retract the bolt. A rim lock has a unique characteristic of the key operating the lock from both ends of the keyway.
A rim lock is quite different than other locks based on the appearance. Most rim locks are warded locks, which uses wards to avoid unauthorized access.
The history of a rim lock
The history of a rim lock can date back to 1830 in England and the pioneer of the lock was James Carpenter. James Carpenter then began working on the improved and new designs along with a guy named John Young. The two guys wanted to split the patent for the resulting lock, but they ended up with a joint patent. James Carpenter patented a rim lock with straight action, while John Young continued to patent what we called the foundation of the modern mortise lock.
James Carpenter laid the foundation for the modern rim lock, but John Carpenter was the one who really affect how the rim lock is used today. John Carpenter make some modifications to make the rim lock used in two directions. A rim lock is used for more than 150 years and it is used even now. A rim lock can stand the test of time, but it is not widely used like it was before.
In the past, rim locks were used for interior and exterior doors. Nowadays, they are usually used for interior doors and shed doors which are too thin to cover the deadbolt locks.