Chubb detector lock

[1] In response, Jeremiah Chubb, who was working with his brother, Charles, as a ship's outfitter and ironmonger in Portsmouth,[2][3] invented and patented his detector lock in 1818.

They moved from Portsmouth to Willenhall in Staffordshire, the lockmaking capital of Great Britain, and opened a factory in Temple Street.

[7][8][failed verification] A number of improvements were made to the original design but the basic principle behind its construction remained unchanged.

The original lock used four levers, but by 1847 work by Jeremiah, Charles, his son John and others resulted in a six-lever version.

A later innovation was the "curtain", a disc that allowed the key to pass but narrowed the field of view, hiding the levers from anybody attempting to pick the lock.

Joseph Bramah exhibited one of his locks in the window of his shop and offered 200 guineas (£210 and equivalent to £24,600 in 2023) to anybody who could devise a method of picking it.

Sarah MacLean's novel Wicked and the Wallflower, set in 1837, has a Chubb lock on the door of the Bareknuckles Bastard's smuggling warehouse.