Fig. 4. General View of the Soss Die-casting Machine
Referring to the illustrations [Figs. 5] and [6], A is the base and frame of the machine, B is the heating chamber located at one end of the machine, and within this heating chamber is the tank C, shown in [Fig. 6]. This tank contains the metal from which the die-castings are made, and the metal is heated by the burners D. These burners are fed by air and gas through piping on the side of and beneath the furnace. To facilitate lighting the burners and inspecting their condition at any time, there is an opening (not shown) through the firebrick lining of the furnace and the outer iron wall, on a level with the top of the burners. There is also another opening through the furnace wall to allow the gases due to the combustion to escape. Through the bottom of the tank, well to the inner side of the furnace, runs the cylinder E. Below the bottom of the tank, the cylinder makes a right-angle turn, extending through the furnace wall and terminating just outside of the wall. The orifice of this cylinder is controlled by gate F. In that part of the cylinder that extends upward into the tank, there is an opening G that allows the molten metal to run into the cylinder from the tank. Working in this cylinder, is the piston H, that is used in forcing the metal into the dies. The compression lever I, hinged over the inner furnace wall, is kept normally raised by spring pressure, and is connected to the piston by means of the link J.
Fig. 5. Working Parts of the Soss Die-casting Machine
At the opposite end of the machine from the furnace, is the mechanism for operating the dies. This mechanism consists of a pair of square rods K, upon which are mounted the sleeves L. These sleeves have a long bearing surface and are attached to the die-plate M. Lever N at the end of the operating mechanism controls the movement of these sleeves by means of links O. Upon these sleeves is mounted a secondary set of sleeves P, attached to the other die-plate Q, and whose movement is controlled by lever R, through links S. This second set of sleeves is free to travel with the first set, and in addition has an independent movement of its own on the primary sleeves. It is the function of lever R to bring die-plate Q up to die-plate M by means of links S and sleeves P; and it is the function of lever N to bring both of the die-plates up to the outlet of the cylinder by means of links O and sleeves L. This system of sleeve-mounting is one of the distinctive patented features of the Soss machine. The orifice of the cylinder E is conical in shape and exactly fits the cup-shaped opening in die-plate M, so that when the two are brought together, the joint is metal tight. At the center of this opening, and extending through the die-plate M, is an opening that leads to the dies mounted on the inner faces of the two die-plates, and a continuation of this opening extends through die-plate Q in which the sprue-cutter U works. Attached to the outer side of this die-plate are two slotted brackets. In the slot of one of these is pivoted the lever T, and in the slot in the opposite bracket are bolted two stops that limit the motion of the lever. This lever operates the sprue cutter U, that works through the opening in die-plate Q. The sprue-cutting mechanism is best shown in [Figs. 5] and [6]. At the left of [Fig. 5] may be seen a rubber hose connected to the air piping. This hose is used for cleaning out the dies after each casting operation.
Operation of the Die-casting Machine
The metal for the die-casting machine is mixed in the proper proportions for the work in hand by means of a separate furnace, before being poured into the tank of the machine itself. The burners are lighted and the dies are set up on the two die-plates. As soon as the machine has “warmed up,” so that the metal is in a thoroughly melted condition, the sprue-cutting lever T is thrown back, leaving a clear passageway to the die cavities. Lever R is pulled backward, thus bringing die-plate Q up to die-plate M, which operation closes the two halves of the die. Then lever N is thrown forward, thereby bringing the closed die up to the body of the machine, with the nozzle in close contact with the outlet of the cylinder. Next, the gate F is opened, and the man at the compression lever I gives the lever a quick, hard pull, forcing the metal in the cylinder downward and into the dies. The molten metal literally “squirts” into the dies. Gate F is now closed; lever N is pulled back to remove the dies from the cylinder outlet; and the sprue-cutting lever T is pushed forward, cutting off the sprue and pushing it out of the nozzle into the kettle placed beneath it. The lever R is pushed forward, and a finished casting is ejected from the dies.
An important advantage that this machine has over other die-casting machines is the fact that the metal for the castings is taken from the bottom of the melting pot, whereas most other machines use metal from the top of the tank. At the bottom of the tank the metal is always the best, as it is free from impurities and dross; hence, there is little chance for the formation of blow-holes. A handful of rosin thrown into the melting tank occasionally helps to keep the metal clean, but the metal nearest the surface always contains more or less foreign matter.
Fig. 6. Section of Soss Die-casting Machine