Lever resistance (or load). It is common to call the input force "the effort" and the output force "the load" or "the resistance." This allows the identification of three classes of levers by the relative locations of the fulcrum, the resistance and the effort: These cases are described by the mnemonic "fre 123" where the fulcrum is in the middle for the 1st class lever, the "r"esistance is in the middle for the 2nd class lever, and the effort is in the middle for the 3rd class lever. The lever is a movable bar that pivots on a fulcrum attached to
Lever action the cylinder to the next position and cock the internal hidden hammer. Multiple lever action designs including the Volcanic pistol were designed before the American Civil War, but the first significant lever-action designs were the Spencer repeating rifle and Henry rifle. The Spencer was a magazine-fed lever-operated breech-loading rifle designed by Christopher Spencer in 1860. It was fed from a removable seven-round tube magazine, enabling the rounds to be fired one after another, and which, when emptied, could be exchanged for another. Over 20,000 were made, and it was adopted by the United States and used during the American Civil