Fig 2Otis's catch, 1861 patentSpace cuts the rope · R resetsrope pulling · pawls held clear of the teeth
Pawls on the bent levers: held in by the rope, thrown out by the springRacks with teeth hooked upward, on both uprightsDrawn from US patent 31,128 (15 January 1861). The rope lifts bar F, which pulls the levers' inner ends up and holds the pawls clear of the teeth. If the rope breaks, spring e drives F down, the pawls swing into the racks, and because the teeth hook upward the load drives them in harder. Bops Lab