The Padlock Patent Archive

Three centuries of keeping things shut

Brass case padlock

Technical patent drawing showing nine figures of a padlock: an exterior view with U-shaped shackle and escutcheon, two cutaway interior views revealing internal hook and latch mechanisms, two individual hook pieces of differing weight, a latch piece, two keys with hollow bow handles, and a small bent spring trap.PADLOCKWilliam Ball · April 16, 1842Patent drawing sheet showing six figures of a 19th-century padlock with a curved shackle arm, rotating face-plate with multiple key-holes, internal sliding bolt, tumbler, pinion and spring lever mechanisms, and a detachable key.IMPROVEMENT IN PADLOCKSDaniel Zeiler · February 27, 1872Patent drawing of a round padlock showing internal hooked dog, tumbler springs, and lettered parts, with a separate flat push key and cutaway views of the shackle open and closed.IMPROVEMENT IN PADLOCKS.Frederick Egge · August 27, 1878Patent drawing sheet showing twelve figures of a U-shaped shackle padlock, including exterior views, cross-sections revealing internal tumbler plates C and springs H, the key F, and a rotating guard plate L covering the keyhole.PADLOCK.William F. Troast · July 24, 1888Patent drawing of a padlock showing its curved shackle, internal pivoted tumblers with lugs and springs, and a flat stepped key used to release the mechanism.PADLOCKSamuel P. Stein · November 4, 1890Patent drawing of a padlock showing a U-shaped shackle inserted into a casing containing pivoted tumblers, sliding dogs, springs, and a twisted key mechanism, with seven labeled figures illustrating the internal parts and key.PADLOCK.Frederick W. Schultze · February 21, 1893Patent drawing of a padlock showing the internal latch, spring, and lever mechanism in Fig. 1, and a vertical cross-section of the same lock with the shackle and dummy button in Fig. 2.SECRET COMBINATION LOCKJoseph Ciotola and Dominick Polidoro · May 23, 1922