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The Padlock Patent Archive

Three centuries of keeping things shut

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Early 20th century hardware

Patent drawing of an egg-shaped padlock housing shown applied to a hinged hasp with a staple, plus a cutaway longitudinal section revealing an internal spring-loaded tumbler, bolt, and key mechanism.

PADLOCKWilliam Gordon Parmele · July 14, 1925

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.

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