The Bearing-Block Can Opener: Lean on the Wall, Not on the Contents

Pressing on a full can's top to cut it forces the contents up through the cut. Guy C. Humphries of Washington, D.C., received US 84,122, dated 17 November 1868, for a can and box opener in which a knife-and-handle lever turns on a fulcrum pin through a hinged bearing block whose two faces rest on the can's outside wall; the knife cuts as it rises, and "the pressure at all times being against the outside wall of the can, avoiding the pressing out of the contents." This rung shows where the cutting force goes, then builds the lever and bearing block and opens a full can.