The Padlock Patent Archive

Three centuries of keeping things shut

Spring tumbler

Technical patent drawing showing three cutaway views of a padlock case with spring tumblers and a hidden safety bolt engaging a notched hasp, plus detail views of the bolt, bearings, and a double-bitted key.PADLOCK.George McGregor, Robert Lee, and Thos. G. Clinton · August 26, 1851Patent drawing sheet showing an egg-shaped padlock in multiple perspective and cutaway views (Figs. 1-13), revealing internal rotating disks, springs, a curved bail, and two ornate extension keys with notched wards.IMPROVED PADLOCKSamuel G. Cabell · December 14, 1869Patent drawing of a round padlock showing six figures: the shackle and tumbler mechanism in locked and unlocked states, an exploded view of the lifted mechanism, a front elevation of the assembled lock, an edge view of the case, and a flat sheet-steel key shown from front and edge.IMPROVEMENT IN PADLOCKSFredrick Egge · July 14, 1874Patent drawing of a round padlock showing internal dog, tumblers, and pivoted shackle mechanisms across five figures, with a separate key illustration.IMPROVEMENT IN PADLOCKSFriend W. Smith and Fredrick Egge · September 4, 1877Patent drawing of a hasp-lock showing a long hasp arm H attached to a circular lock case c containing an internal bolt mechanism with tumblers, teeth, and a staple, alongside a cross-sectional view and an inverted bolt view labeled Fig. 1 through Fig. 4.IMPROVEMENT IN HASP-LOCKS.Conrad Fichter · April 2, 1878Patent drawing of an oval cast-iron padlock shown with its side plate removed, revealing a central shackle spindle surrounded by spring-loaded sliding tumblers, alongside separate views of the shackle and tumbler details.IMPROVEMENT IN PADLOCKSWilliam H. Bramble · July 30, 1878Patent drawing sheet showing a heart-shaped padlock with internal spring tumblers, a hinged shackle, and two flat keys with stepped bits, labeled with reference letters for the case, dog, tumblers, and springs.IMPROVEMENT IN PADLOCKSWilliam Baldwin · November 19, 1878Patent drawing of a U-shaped shackle padlock showing internal spring-steel tumblers, a key inserted from below, and cross-sectional views labeled Fig. 1 through Fig. 8 with lettered parts such as A (case), B (shackle), C (tumblers), and F (key).PADLOCK.William F. Troast · December 31, 1889Patent drawing of a circular padlock mechanism showing a rotary bolt, spring tumbler, pivoted dog, and hasp slot, with eight labeled cross-section and elevation figures.PADLOCK.Henry Roland · August 3, 1897