US1947818A - Pump for pumping molten metal - Google Patents

Description

Feb. 20, 1934. e. H. WHITE PUMP FOR PUMPING MOLTEN METAL Fil ed July 7, 1950 I 72116722507" ffirZera Wife 5 Patented Feb. 20, 1934 UNITED STATES PUMP FOB. romme MOL'IEN mz'rar.

George Herbert White, Philadelphia, Pa., aesig'nor to Patent Product Corporation of Ohicago, a corporation of Delaware Application July '1, 1530. Serial No. 465,912

1 Claim. (or 22-10) My invention relates to improvements in pumps for pumping molten metal and the like and has for one object to provide a new and improved form of pump which will be self cleaning. Other objects of my invention .will appear throughout the specification and claim.

My invention is illustrated more or less diagrammatically in the accompanying drawing, wherein- Figure 1 is a side elevation in part section of a pump and plunger;

Figure 2 is a side elevation of a modified form of plunger;

Figure 3 is a side elevation in part section of a modified form of cylinder and plunger;

Figures 4, 5 and 6 are similar views showing further modified forms.

Like parts are indicated by like characters throughout the specification and drawing.

When molten metal such as lead is cast by means of a pump such as used in connection with type setting machinery, die casting and the like, experience shows that there is a tendency for the pump piston and cylinder to clog or become foul from the presence of refuse such as metallic oxides and the like and periodically therefore it is necessary to withdraw the plunger from the cylinder to enable the plunger and cylinder to be cleaned.

This difiiculty has to some extent been obvi-- ated in the past by providing a plurality of annular grooves in the piston or plunger. These annular grooves traveling along the cylinder with their sharp edges adjacent the cylinder wall tend to scrape oil the deposit and increase the length of time during which operation can take place without cleaning but as soon as the annular grooves are filled with refuse the plunger must be withdrawn and the grooves cleaned out.

I have discovered that if the plunger or the cylinder 5 or both are provided with one or more spiral grooves extending throughout such part of the cylinder asv will permit the groove to be exposed to both ends when pressure is applied, that some of the molten metal will leak back through such grooves and carry with it the deposit which would otherwise remain in the grooves and ultimately clog the pump. The leakage through these grooves is small enough so that it does not adversely aflect the operation of the device but is sufiicient to provide a wiping stream or flow through the spiral groove whereby the material is washed out.

In Figure l, A is a melting pot. It contains a mass of molten metal A The lug A and pin A indicate any suitable support for the pot. Immersed in the body of molten metal in the pot is a pump cylinder A having a diso0 charge spout or passage A terminating in a discharge nozzle A which is' adapted to be brought'into register with the mold by a y suitable means forming no part of my invention and not here shown. A is a port leading through the wall of the cylinder and communicating with the body of molten metal so that when the piston is withdrawn, the port is opened, molten metal flows in to fill the cylinder. When the piston moves forward the port is closed first and thereafter pressure is applied by the piston or, plunger to the metal in the cylinder to cause it to be forced out through the pipe A and nozzle A.

B is a rock arm adapted to be operated by 7 any means not shown to cause piston movement. This rock arm is pivoted to a piston rod B which piston rod in turn is pivoted to the piston B. B is a handle of 'wood or other suitable insulating material on the piston rod whereby so the piston rod and piston may be manipulated by hand when desired to withdraw them from working relation with the pump. In Figure 1, the inner wall of the cylinder is shown as being smooth. The outer periphery of the piston has 35 a single spiral groove B wound threadwise about the piston so as to provide sharp scraping edges in opposition to the cylinder wall and so as to provide an elongated spiral escape passage from the interior of the cylinder about the periphery of the piston and between it and the cylinder communicating at its other end with the body of material in the pot.

In Figure 2, there are two spiral passages B B as a substitute for the single spiral passage B of Figure 1. In Figure 3 the spiral passage i3 is located in the single peripheral wall of the'cylinder and in this case the piston is shown provided with a plurality of annular grooves 13 In Figure 4 the piston has the single 10o spiral groove 3 but the cylinder has an additional spiral groove B of the same pitch as the groove 3* and traveling in the same direction. In Figure 5, the spiral groove B on the piston is associated with a spiral groove B in the wall 05 of the cylinder but in this case the two grooves are wound in opposite directions. In Figure 6 there is associated with the groove B on the piston a groove l3 in the cylinder wound in the same direction but, of different pitch. lio

Many other combinations of grooving might be provided depending upon circumstances but they all have this in common, that there is provided a sharp shouldered cleaning or refuse receiving groove and that groove whether in. the cylinder or in the piston or in both is wound screw threadwise so as to provide a long spiral passage through which molten metal may flow when pressure is applied to the piston so that such molten metal at each piston stroke may tend to clean out and discharge from the piston and cylinder the fouling material or refuse which by the piston reciprocation is caused to be scraped off from the opposed piston and cylinder surfaces and deposited in the groove CERTIIFHCATE v Patent No. l,94i7,8l8.

mergers I claim:

In combination, a melting pot, a cylinder projecting upwardly from the bottom of the pot and adapted to be entirely immersed in the molten metal, a cylindrical opening at the top, an intake'port through the wallof the cylinder adjacent the bottom of the pot, a piston adapted to reciprocate in the cylinder, a tortuous passage bounded by the cylinder and the piston communicating with the space beneath the piston within the cylinder at one end and with the body of metal above the cylinder at the other end, the edges of the walls bounding the tortuous passage being sharp.

G. HERBERT WHITE.

or connection.

February 20, 1934.

GEQRGE HERBERT WHII'IIE.

it is hereby certified that the above numbered patent was erroneously issued to "Patent Product Corporationoi Chicago, a corporation of Delaware," whereas said Letters Patent should have been issued to Chester A.

Macomic, Chicago lllinois, said Macomic being assignee by mesne assign- ,lnents oi the entire interest in said invention, as shown by the records of assignments in this office; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Otiice.

Signed and sealed this 3rd day oi April, A. n. 1934.-

(Seal) 1F. Vi. Hopkins Acting Commissioner of Patents.

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