Skip to content

The Padlock Patent Archive

Three centuries of keeping things shut

Browse Dates Inventors Types About

Hook-prong staple

Patent drawing showing a long curved hasp with a hook-prong end, a cutaway lock mechanism with an internal sliding bolt and spring, a cam-notched key head, and a modified chain-attached hasp variant.

HASP-LOCK.Charles P. Pond · June 30, 1885

United States patent drawings and specifications are works of the U.S. government and are in the public domain — they were never copyrighted. Download them, print them, frame them. Our commentary and descriptions are © 2026 The Padlock Patent Archive.

About · Terms · Privacy · Corrections welcome — this archive gets better when collectors write in.