This section is from the "Modern Machine Shop Construction, Equipment, And Management" book, by Oscar E. Perrigo. Also see Amazon: Modern Machine Shop Construction, Equipment, And Management.
Special conditions. Some early history of the foundry. Modern foundry appliances. Plan of the foundry. Tram car tracks. The transportation of materials. Charging cars. Elevator to cupolas. Blast apparatus. Electric motors. Bench work. Pneumatic hoists. Their capacity. The air compressor. Molding machines. Sand sifters and mixers. Molding pits. The cupolas. Foreman's office and storeroom. The heating apparatus. The shipping room. The pickling beds. The pickling vat. The cleaning room. The core room. The core oven. The flask room. The wash room. The water-closets. The lockers.
The equipment of the iron foundry necessarily differs in many respects from that of the other departments heretofore considered, as to its product, its work, and the necessary arrangements for carrying it on. These requirements, while they have changed much since the earlier plants for this work were established, have not perhaps undergone so great a change in a general way as have those of the machine shop. The early plants were, of course, very crude and primitive affairs, and iron was often melted in crucibles somewhat as brass is melted now. Most of the work done was of the plainest kind and little attention was paid to symmetrical or artistic effect.
Early history shows that the making of iron castings was one of the oldest mechanical industries of the country. In the year 1643 John Winthrop arrived in this country from England, bringing with him the necessary number of skilled workmen for this purpose, and built a small iron foundry in Lynn, Mass., and the fact that the first casting which was made was "a small iron pot holding about a quart" shows the modest capacity of the foundry. The casting is said to have been made "from native ore".
Little progress seems to have been made for a considerable time in enlarging the original scope of the work from its early beginnings, so far as records of the facts are known. In 1735 an iron foundry was established in the little town of Carver, Mass., and a second one was built in the year 1760, wherein the historic "Massachusetts Teakettle" was cast.
Another foundry was built in 1793, and was burned down in 1841. The proprietors of this foundry were Bowers & Pratt. A relative of the latter partner established a foundry in Wenham, Mass., and his son, at a later date, built a foundry in Watertown, Mass., which was the original of the now well-known foundry of the firm of Walker & Pratt, for whom the author had the privilege of making the first drawings of their heating apparatus to be reproduced by the original photo-engraving process invented by Moss, and operated by the Moss Photo-Engraving Company, on Park Place, New York City. Following the gradual development of the iron-founding business from the early times is very interesting, but too long a story for the available space of these pages.
In these later years the addition of the traveling crane, the pneumatic hoist, the application of electricity, the iron flasks, the sand blast system for cleaning castings, and similar improvements have changed many of the older methods, and rendered the work less laborious and the output much larger. At the same time the quality of the work, both in its practical and in its artistic features, has been greatly improved and more economically produced.
The foundry floor has been particularly described in Chapter XI (The Construction Of Floors) on floors, in the Part First on Machine Shop Construction, to which the reader is referred for detailed information on this point.
Fig. 115 shows the general arrangement of the foundry and its equipment. The central portion is provided with a traveling crane, and under this and the two jib cranes shown the heavy molding and casting are done. Tram car tracks, located as shown, bring in any Stock and material, such as sand, flasks, pig iron, coal, etc., as may be necessary, upon cars specially constructed to adapt them to each class of load to be carried. Turntables are provided at the intersection of the tracks, in preference to curves and switches, as they occupy much less room, do not require any more time to operate, and the cost is nearly the same, for equipment offering like facilities. The special construction of these tracks and their accessories will be particularly described in a future chapter on shop transportation.
In bringing pig iron, coal, etc., to the cupolas the material is brought on the cars to the turntable scale in front of the elevator, and there it is weighed, then run upon the elevator, raised to the charging floor and the cars run upon the branch tracks, and thence to the cupolas, as shown in Fig. 116. The charging cars are specially constructed for this purpose, and are substantially the same as used by the Vilter Manufacturing Company in their foundry in Milwaukee, Wis.
A rear elevation of one of these cars is shown in Fig. 117, and a side elevation in Fig. 118. The frame consists of two similar iron castings for sides, held together by cast iron cross rails bolted to them, as shown. The car body A is composed of 2-inch planks, lined with sheet iron, and supported by wrought iron, forged straps B, B, of U-shaped form, at the back and front, and by cast iron angle supports C, C, near the center. Upon these supports are formed downwardly-projecting lugs, by means of which the car body is pivoted by the rod D to the frame, as shown in Fig. 118. The greater part of the load is placed back of this pivot, thus holding the car body in a horizontal position. Pivoted to the rear end of the car body is a rack E, engaging a pinion on a horizontal shaft F, which has fixed upon its front end the spur gear G, engaging the spur pinion H on the shaft J, which is squared on the front end for the application of a crank, by means of which the rear end of the car body may be raised and the contents of the car dumped. The dumping position is shown by dotted lines in Fig. 118. The car is of very simple construction; the gear and rack teeth are cast, the wheels and gears bored, and the hubs faced, but not turned on the outside. Several of these cars should be provided, so that there may be no waiting on the charging floor for either pig iron, scrap iron, coal, or coke, during the progress of a heat, when time is valuable.