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THE FORGE SHOP
Its present restricted sphere. Improved facilities. Case-hardening and tempering. The
addition of machine tools to its equipment. The proper location of the forge shop. Its special construction. Transportation of stock and material. Coal and bar stock storage. Foreman's office. Portable scale. Forge fires. The down-draft system. Construction of forges. The blower. Blast pipes. Arrangement of blast apparatus. Steam hammers. Drop presses. Special heating furnaces. Annealing and case-hardening furnace. Detailed description. Cutting-off machine. Power hack saws. The cold saw. Heavy shear. Heavy turret lathe. The forge lathe. Work benches. Steam supply. Compressed air. Electric motor drive. Jib crane. Overhead trolleys. Pneumatic hoists. Bar stock storage rack. Shop rack for bar stock. The wash
The water-closets. The lockers. Compactness of the design.
It is undoubtedly true that since the very general introduction of turret lathes, forming lathes, and the large variety of similar machines now in use in almost every machine shop making any pretense to modern equipment and up-to-date methods of doing work, the forge shop has lost considerable of its importance as one of the indispensable departments upon which the machinist of former times very largely depended for much of his material for the better classes of work. The introduction of steel castings, malleable iron castings, and other similar materials, superseding in many cases the old-time forgings, has also been an important factor in the same direction, and has decreased the cost of materials of complicated form, and at the same time provided the machinist with materials which have admirably answered the purpose as to strength, and lessened the amount of machining necessary for their practical
And yet, while the forge shop may have decreased in the matter of importance in the making of forgings, there will always remain the demand of the machine shop for a certain amount of strictly machine forgings of iron and steel which cannot be met by any other material. Many great and important advances have been made in forging by use of improved hammers, by dies in connection with them, and by the process of drop forging, yet there is a large demand for forgings requiring the services of the skilled machine forger with his expertness in hand forging, as well as his technical knowledge
of handling steel of various qualities, his expert knowledge of how to produce forgings of complicated and intricate forms, and the thousand and one conditions and requirements demanded in successfully bringing out such work, correct in form and structure, and within a reasonable cost.
In the matter of case-hardening and tempering the forge shop department has increased materially, as there has never been a time in the past when hardened and ground steel work has been as much used in the better qualities of machine construction as at present; and case-hardening has reached such an extent that it is rare to find nuts, cap screws, and the like on any well-constructed machine that are not protected from injury by this valuable process.
While the actual forging work of the forge shop has decreased its scope, it has in a general way much increased in volume, since it is now customary to add to its equipment several machine tools, such as cutting-off machines, forge lathes, heavy turret lathes, cold saws, power hack saws, and other similar machines for roughing out work, which in many instances can be much more economically done by these methods than by confining the operations to forging under the hammer. In this case the appropriate machines for these purposes are included in the equipment of the forge shop and located as will be presently described, and as shown on the plan in Fig. 123.
The foundry floor, the engine foundation, and many of the foundations for machines in the machine shop, should be kept as free from jar, and from shocks sufficiently strong to disturb the ground by vibrations, as possible. For this reason the forge shop is placed as far from these buildings as may be convenient; therefore, in the rear corner of the plant, and opposite the rear end of the machine shop. The spur track from the railroad, which supplies shipping facilities and brings to the plant the raw materials necessary for its use, runs across the rear end of the group of buildings, in the rear of the machine shop and storehouse. It continues in a curve around the rear corner and up the side to the foundry gate, rising, as it goes to a height sufficient for conveniently dumping coal, coke, molding sand, etc., into the storage sheds located along that side, the first of which is shown at the left of the forge shop in Fig. 123. The curve of the railroad track cuts off somewhat of this rear corner of the building space and therefore the forge shop is located far enough from the rear line to accommodate it, and the space so left is utilized for a one-story building containing a space for the forge coal, another for bar stock storage, and the wash room and water-closets.
The forge shop is, like the other buildings of the plant, built of brick, with steel roof construction, the roof trusses being supported in the center by steel columns. It is lighted, not only from the side windows, but from those in the monitor roof, the sashes of which are hung on pivots and controlled by cords reaching nearly to the floor, by which they may be operated when neces
reference to the forge shop, as well as the location of the railroad track, and Fig. 123, which also shows the contiguous buildings and their positions in sary for ventilation. The general plan of the forge shop is clearly shown in
FIG. 123. — General Plan of Forge Shop, showing Proper Arrangement of the Machine Tools, etc.
the tram car tracks connecting this department with the railroad tracks in the rear and the other departments toward the front of the plant.
For convenience in bringing in stock and taking out finished work the tram car tracks run nearly midway through the forge shop, as shown, and are connected by their branches with the foundry, the machine shop, storage sheds, and practically all departments of the plant, as well as at three points with the railroad track, two of these being shown on the plan.
The foreman's office is located in the front corner of the shop, and has connected with it the usual foreman's store closet for such minor supplies as are more conveniently kept there than in the general storeroom near the offices. A fixed desk furnishes a convenient place for spreading out drawings, and a private desk is provided for the foreman's personal use. Outside of the office is a forge shop scale for weighing stock and forgings. This scale should be mounted on wheels so that it can be readily moved to any part of the shop where it may be needed.
Along the outer wall of the shop are located five regular forge fires having chimney flues built into the wall for their accommodation. These latter will not be necessary if the system of down-draft forges is used. This form of forge has several good qualities, not the least of which is that it offers less obstruction in handling large pieces of work, as it may be conveniently placed at a distance from the wall if desired, and will furnish quite as good ventilating facilities in clearing the shop of coal gas as those connected with separate chimneys. The draft may be increased or decreased at the will of the operator, particularly in the case of forges manufactured by the Buffalo Forge Company, in which a hinged and adjustable hood may be closed down over a fresh fire and raised for the handling of the work to be heated, as may be desired. If these down-draft forges are used it will be necessary to provide an exhaust fan with the proper connecting pipes for carrying off the smoke and gases, which may be delivered to one chimney, thus avoiding the expense of building the other four. Such an arrangement is very clean and wholesome for the workmen, when compared with the method shown, but considerably more expensive in its first cost, as well as requiring extra power to operate it.
The forges shown on the plan should be of such construction that the tuyeres may be readily attached and detached when necessary, for cleaning or for repairs. They should have such a form of bottom valve or gate as to readily discharge the clinkers or slag that may find its way down to it. These forges are usually constructed of cast iron and supported upon four legs, so as to give convenient access beneath them for cleaning, attaching the blast pipe, repairing, etc. Each should have, cast with it, or attached to it, two narrow troughs, running the length of its front, or shortest side, for holding coal and water. Many excellent ones are in the market and can be purchased more
economically than they can be built on the premises. The blast pipe should be arranged to slide on and off easily, in case it is necessary to disconnect it for cleaning or repairs, and it should be provided with a regulating valve or gate, fitting as nearly air-tight as may be, and operated by a lever conveniently located within the reach of the operator. These forges are usually made of rectangular form, but large fires are often made upon a circular forge, whose sides extend to the floor. They need not necessarily be provided with the water and coal troughs as mentioned above, as they are usually used for heating work for the steam hammers, drop presses, and similar large work, rather than for tempering, tool forging, or small work of this class.
The blast for these forges, for the heating furnace, for the drop presses, and for the case-hardening and annealing furnace, is furnished by a fan blower designed for a pressure necessary for forge work, and having an outlet of six inches in diameter, equivalent to a No. 3 Sturtevant steel pressure blower, which is admirably adapted for this purpose. It should be located over the bench near the forges, at the front end of the shop, so that there may be no unnecessary turns or bends in the pipe leading to the forges. These pipes should be placed along the walls near the floor, but never beneath it. In one shop the author saw blast pipes, composed of vitrified drain tiles, the joints made with Portland cement, and laid less than a foot beneath the surface of a dirt floor of the forge shop, and at one point passing directly under a bolt heading machine.
As might have been expected, the jar of the shop floor broke up the pipes and destroyed their usefulness. The blast pipes should be constructed of heavy galvanized iron, well fitted and fastened, and as nearly air-tight as may be. They should be easy of access, for the possible connection of additional pipes and for convenience of making repairs, which will have to be made sooner or later. They might be placed six or seven feet high, and along the walls, but this position will necessitate about thirty feet of additional pipe, increasing the friction of the air and consequently the power required, with no especially compensating gains other than getting the pipes up out of the way somewhat.
Some of the more important rules for setting up and connecting forge blowers may be here given. Place the blower as near as possible to the forges. Make the pipe connections as direct as possible. If bends or elbows are absolutely necessary, make the curves of large radius, and with no abrupt angles; the inside radius of an elbow should not be less than twice the diameter of the pipe. Have the aggregate areas of all the outlet pipes at least equal to the delivery pipe at the blower. If the pipes must carry the air over one hundred feet, speed up the blower proportionately above the figures given in the manufacturers' catalogue. In any event, the blower should be run at