Editor's note: The lazy tongs is a parallel link mechanism that will maintain a vertical line parallel as it extends the reach. In electric rail applications it is sometimes called a pantagraph mechanism. The lazy tongs can also be found in the Reuleaux model collection in model T-2 as part of a series of parallel mechanisms. The lazy tongs can be seen in the machine drawings of Leonardo da Vinci especially in his Codex Madrid I. This Clark model was originally numbered #16 in the Newark Museum collection and now carries the number 112. [F.C.Moon, 2005]

Francis Moon 2005-00-00