US2699933A

US2699933A - Dross remover

Info

Publication number: US2699933A
Application number: US317280A
Authority: US
Inventors: Sr John T Siefert
Original assignee: Northrop Grumman Corp
Current assignee: Northrop Grumman Corp
Priority date: 1952-10-28
Filing date: 1952-10-28
Publication date: 1955-01-18
Anticipated expiration: 1972-01-18

Description

Jan. 18, 1955 J. T. SIEFERTQSR 2,699,933

DROSS REMOVER Filed Oct. 28, 1952 @www United States Patent DROSS REMOVER .lohn T. Siefert, Sr., Los Angeles, Calif., assignor to Northrop Aircraft, nc., Hawthorne, Calif., a corporation of California Application October 28, 1952, Serial No. 317,280

3 Claims. (Cl. 266-37) My invention relates to the lield of skimmers and the like and more particularly to dross removers.

In the preparation of pig lead it has been found necessary to introduce certain impurities into the molten mixture in order to drive out noxious gases as well as to aid in the removal of other undesirable elements through the medium of a chemical reaction or combination. Not all of the impurities are removed from the molten mixture at the time the lead is made into pigs. The pigs are transported, stored and subsequently remelted for purification, alloying, casting into final shapes, or into ingots for rolling. During the remelting process a layer of the molten mixture, similar to slag in appearance but composed of metallic oxides, appears on the surface. This layer must be removed from the molten metal before the metal can be prepared for its intended use. At present the devices used in removing dross have been unsuccessful in eliminating the large losses of molten lead which adheres to the skimmer or the dross retained by the dross remover during the skimming and removing process.

It is, therefore, the object of this invention to greatly minimize the loss of the molten lead in the dross removal process. This has been effected by designing a skimming device which is devoid of uppermost flat surfaces upon which the molten metal might form globules and thus be retained and consequently removed from the molten solution. Instead of providing the aforementioned flat surfaces, my device has a grid of triangular elements positioned apex upward from which the molten metal slides back into the pot containing the solution, thus precluding any adhesion of the molten metal to the rid. g For a complete disclosure of the invention, a detailed description thereof will now be given in connection with the accompanying drawings forming a part of the specication, wherein:

Figure l is a plan view of the dross remover.

Figure 2 is a cross-sectional view of the dross remover along the line 2-2 in Figure l.

Figure 3 is a cross-sectional view of the dross remover along the line 3--3 in Figure 1.

Referring to the drawings, in which similar reference characters designate corresponding parts, the grid is of generally rectangular shape, having opposite faces one of which is concave, and is composed of triangular shaped bars 1 equally spaced on top 2 and bottom 3 and held together by a frame 4 to which a handle 5 is attached. The sides 6 of the frame are bowed outwardly as is the front side 7, the side 8 attached to the handle is straight. The grid as a whole is bowed downwardly as indicated by numeral 9 and thus the innermost or center bar 10 is the most bowed or lowermost when viewing the dross remover from the side. The slope of the sides 6a, of the two side bars 6, is less, at the mid point, then that "ice of the grid members or bars and gradually increases, as it approaches the ends, until, at that point, it is steeper than the grid bars, the bottom spacing 3 remaining constant. The inner portion of the front 11 and back 12 sides slopes inwardly as shown. The frame 4 is rounded on all corners to eliminate sharp edges.

My invention operates as follows: The dross is swept up into the grid work and there retained due to the basketlike shape which the remover has because of its generally bowed configuration. Any molten metal which is taken in with the sweep of the skimmer readily gravitates through the spacing at the bottom 3. The basket-like configuration allows the operator to jar the skimmer on the side of the container holding the molten metal, thus further ridding the dross of any remaining metal and still keeping the dross within the remover.

While in order to comply with the statute, the invention has been described in language more or less specic as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprises a preferred form of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

What is claimed is:

1. An implement for skimming dross from molten metal comprising: a generally rectangular grid having opposite faces, one of which is concave, and comprising a series of laterally spaced, generally parallel bars, each having a sharp longitudinally extending edge lying in a surface dening the concave side of said grid, each pair of opposed side surfaces of adjacent bars converging from the said sharp edges of said adjacent bars toward the other face of said grid and forming edges at said other face that are uniformly spaced throughout the length of said bars for drainage of molten metal therebetween, the end bars of said series having side surfaces which diverge from the said sharp edges thereof towards said other grid face, and cross bars connecting the ends of said parallel bars, said cross bars having sharp longitudinally extendlng edges on the concave face of said grid with side surfaces which diverge therefrom toward said other grid ace.

2. An implement for skimming dross from molten metal comprises: a generally rectangular grid having opposite faces, one of which is concave, and' comprising a series of generally parallel, uniformly laterally spaced bars, and cross bars connecting the ends of said parallel bars, each of said bars being generally triangular in transverse section and presenting a sharp longitudinal edge to the concave face of said grid with side surfaces that diverge toward the other face of said grid.

3. The structure delined in claim 2,4 in which the end bars of the series and the cross bars comprise a generally rectangular frame having rounded corners with the sharp edges of said end and creas bars constituting continuations of each other.

References Cited in the le of this patent UNITED STATES PATENTS 87,385 Winchester Mar. 2, 1869 703,683 Vrooman et al. July l, 1902 1,760,510 Marvel May 27, 1930 1,786,973 Webber Dec. 30, 1930 FOREIGN PATENTS 980,836 France Ian. 3. 195.1