Quenching Steel Forgings in Heat-Treatment Operation
While the mold is being poured it is in constant motion, and continues so from the pouring station to the end of the conveyor, where the casting is shaken out of the sand. The casting is thrown to one side to cool, the flasks are hung upon hooks on the arm of the conveyor, to be returned to the molder, and the sand drops through a grating in the floor onto a belt conveyor; on this conveyor it is dropped on an elevator, raised overhead and “cut,” or mixed with new sand, and passed on to another conveyor, which deposits it in the hoppers above referred to, ready for the molder’s use. In all this journey the sand is never shoveled.
In casting cylinders, on account of their size and the care needed in setting the cores, a different style conveyor is used. The molder, instead of putting the mold on a pendulum conveyor, places it upon a track, where it is moved by means of a chain. During this travel the various cores are set, and the molds closed, moving to the point where the men with large ladles pour the mold. From this point it is transferred to another track. As it travels down this track, the casting is given an opportunity to “set,” or cool. At the end of this line it is shaken out over a grating, and the sand handled in the same manner as on the smaller conveyors.
Straightening Crank Shafts on Steam Hammers
As soon as the castings have cooled sufficiently they are put into great horizontal cylinders, called tumblers. Small metal stars are placed in these tumblers with the castings, and when the tumbler is full it is started revolving. This shakes all the sand from the castings and they come out clean and bright. This process continues for some time, depending on the size of the castings. Near the tumblers are the grinding wheels, upon which are ground off the rough edges and the castings put into shape for the machine shop. They are sorted, inspected and counted before removing from the foundry.
Another interesting feature is the handling of sand in the core room. The sand is handled entirely in a gallery built above the room, equipped with storage bins and sand mixers. Over each core-maker’s bench is a hopper, connected with the floor of the gallery. When the sand is mixed it is dropped through holes in the floor into the hoppers, which deposit the sand on the bench convenient for the core-maker.
This core room contains perhaps the only endless chain core oven in this country in which are two endless chain conveyors. These have hanging upon them large sets of shelves, upon which the cores are placed for baking. It is impossible to over-bake or under-bake a core, as the rate of travel of the conveyor is fixed at a speed which leaves the core in the oven the correct length of time.
All the aluminum parts as well as a large proportion of the brass, are also cast in this foundry.