I came across this term when I was reading “The Golden Pince-Nez” in The Greatest Adventures of Sherlock Holmes. It has led me to a bit of a history lesson. Sir Arthur Conan Doyle uses it in such a simple way, as though all of his readers are familiar with Chubbs Keys and Chubbs Locks. I suppose there was a time when at least all of England knew about Chubbs.
In this story, Holmes is trying to figure out who murdered Mr Willoughby Smith, secretary to Professor Coram and why Mr Smith would have a gold pince-nez clutched in his hand when he died. During his initial inquiries, Holmes mentions a scratch on a locked bureau that could not have been present the day before. Asking about the key, he is told by the housekeeper, “The Professor keeps it on his watch-chain.”
“Is it a simple key?”
“No, sir, it is a Chubb’s key.”
You can see why my curiosity would be peaked. Though I didn’t know what a Chubbs key was, Holmes knew, and it made sense to him. Further, in his mind, it also explained the scratch.
In 1818, locksmith Jeremiah Chubbs patented a “detector lock” that was designed to keep any but the right key out. If someone tried to pick the lock, the detector mechanism would fall into place, keeping the imposter out and warning the owner that the lock had been tampered with. The original patent was for a lock with two keys, one to open it regularly and one to open the detector mechanism. In 1824, Jeremiah’s brother, Charles Chubb, patented a detector lock with only one key. The brothers would go on to become well known in the world of locksmiths and security. Their company would change names as fathers died and sons took over, and again as they bought out other locksmith companies. When Doyle wrote “The Golden Pince-Nez”, circa 1904, there were two Chubbs factories, one in London and the other in Wolverhampton.
If you would like to learn more about Chubbs locks, I am including a link to an article that I found helpful in my little bit of research for this post. I am sure a Google search would turn up more results for you if you wanted to look further. And as always, I also think you should read “The Golden Pince-Nez” at least once through so you can see how Holmes solves the case.
(I have no affiliation with this website; I just found the article and pictures helpful for my own understanding.)