The Cutting Machines.
After being thoroughly washed, the strips are consigned to the cutting machines. These are in the rear of the rolling mills, and are several in number, each when in active operation cutting two hundred and twenty-five planchets per minute. The press now used, consists of a vertical steel punch, which works in a round hole or matrix, cut in a solid steel plate. The action of the punch is obtained by an eccentric wheel. For instance, in an ordinary carriage wheel, the axis is in the centre, and the wheel revolves evenly around it. But if the axis is placed, say four inches from the centre, then it would revolve with a kind of hobble. From this peculiar motion its name is derived. Suppose the tire of the wheel is arranged, not to revolve with, but to slip easily around the wheel, and a rod is fastened to one side of the tire which prevents its turning. Now as the wheel revolves and brings the long side nearest the rod, it will push forward the rod, and when the long side of the wheel is away from the rod, it draws the rod with it.
CUTTING MACHINE.
STRIP FROM WHICH PLANCHETS ARE CUT.
The upper shaft, on which are seen the three large wheels, has also fastened to it, over each press, an eccentric wheel. In the first illustration will be seen three upright rods running from near the table to the top. The middle one is connected with a tire around the eccentric wheel, and rises and falls with each revolution. The eccentric power gives great rapidity of motion with but little jerking.
The operator places one end of a strip of metal in the immense jaws of the press, and cuts out a couple of planchets, which are a fraction larger than the coin to be struck. As the strips are of uniform thickness, if these two are of the right weight, all cut from that strip will be the same. They are therefore weighed accurately. If right, or a little heavy, they are allowed to pass, as the extra weight can be filed off. If too light, the whole strip has to be re-melted. As fast as cut the planchets fall into a box below, and the perforated strips are folded into convenient lengths to be re-melted. From a strip worth say eleven hundred dollars, eight hundred dollars of planchets will be cut.