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The Padlock Patent Archive

Three centuries of keeping things shut

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Crush-resistant

Patent drawing of a U.S.-marked padlock showing exterior view, internal cross-section with bolt and tumblers, and a double-bitted key.

IMPROVEMENT IN PADLOCKSWarren H. Taylor · July 10, 1877

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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