Machines for forging and condensing the iron

—In England there are employed for the forging and drawing out of the iron, cast-iron hammers of great weight, and cylinders of different dimensions, for beating out the balls, or extending the iron into bars, as also powerful shears. These several mechanisms are moved either by a steam engine, as in Staff ords hire, and in almost all the other counties of England, or by water-wheels when the localities are favourable, as in many establishments in South Wales. We shall here offer some details concerning these machines. The main driving shaft usually carries at either end a large toothed wheel, which communicates motion to the different machines through smaller toothed wheels. Of these, there are commonly six, four of which drive four different systems of cylinders, and the two others work the hammer and the shears. The different cylinders of an iron work should never be placed on the same arbor, because they are not to move together, and they must have different velocities, according to their diameter. In order to economise time and facilitate labour, care is taken to a ociate on one side of the motive machine the hammer, the shears, and the reducing cylinders; and on the other side, to place the several systems of cylinders for drawing out the iron into bars. For the same reason the puddling furnaces ought to be grouped on the side of the hammer; and the reheating furnaces on the other side of the works. IMG:4147767755307473660_illo0704.png:Hammers The hammers, fig. 596. , are made entirely of cast iron; they are nearly 10 feet long, and consist usually of two parts, the helve c , and the head or pane d . The latter enters with friction into the former, and is retained in its place by wedges of iron or wood. The head consists of several faces or planes receding from each other; for the purpose of giving different forms to the ball lumps. A ring of cast-iron a , called the cam-ring bag , bearing movable cams b b , drives the hammer d , by lifting it up round its fulcrum f , and then letting it fall alternately. In one iron work, this ring was found to be 3 feet in diameter, 18 inches thick, and to weigh 4 tons. The weight of the helve (handle) of the corresponding hammer was 3 tons and a half, and that of the head of the hammer, 8 hundred weight. The anvil e consists also of two parts; the one called the pane of the anvil, is the counterpart of the pane of the hammer; it likewise weighs 8 hundred weight. The second g , named the stock of the anvil, weighs 4 tons. Its form is a parallelopiped, with the edges rounded. The bloom , or rough ball, from the puddle furnace, is laid and turned about upon it, by means of a rod of iron welded to each of them, called a porter . Since the weight of these pieces is very great, and the shocks very considerable, the utmost precautions should be taken in setting the hammer and its anvil upon a substantial ma of masonry, as shown in the figure, over which is laid a double, or even quadruple flooring of wood, formed of beams placed in transverse layers close to each other. Such beams po e an elastic force, and thereby partially destroy the injurious reaction of the shock. In some works, a six-feet cube of cast iron is placed as a pedestal to the anvil. Forge hammers are very frequently mounted as levers of the first kind, with the centre of motion about one-third or one-fourth of the length of the helve from the cam wheel. The principle of this construction will be understood by inspection of fig. 605. The short end of the lever which is struck down by the tappet c , is driven against the end of an elastic beam a , and immediately rebounds, causing the long end to strike a harder blow upon the anvil s . The shears are composed of two branches, the one fixed and the other movable, each formed of two pieces. The fixed branch is a cast-iron plate, which forms one ma with a horizontal base fixed to a piece of wood or cast iron buried in the ground. A sharpened chisel is fastened to its upper part by screws and nuts. The movable branch is likewise of cast iron; it bears an axis round which it turns, and this axis pa es through the fixed part. It is also furnished with a cutting chisel, fixed on by nuts and screws. An excentric or an ellipse, moved directly by a toothed wheel, lifts the movable branch of the shears, and forces it to cut the iron bars presented to it. The pre ure exerted by these sci ors is such, that they can cut without difficulty, iron bars, one-half or two-thirds of an inch thick.