About this archive

This site is a curated archive of United States patents for padlocks — the interesting ones: the firsts, the beautiful drawings, the clever mechanisms, the honorable failures. It is built from the original patent documents, which are public domain works of the U.S. government.

Every entry shows the original drawings at full resolution, the key claim in the inventor's own words and in plain English, and our commentary. Bibliographic details are machine-read from 19th-century scans and hand-reviewed; if you spot an error, we want to know.

This archive is one of a family of sites about patented objects that collectors identify by their patent dates.