US2539625A

US2539625A - Apparatus for casting metal rods

Info

Publication number: US2539625A
Application number: US698766A
Authority: US
Inventors: John W Juppenlatz
Original assignee: Lebanon Steel Foundry
Current assignee: Lebanon Steel Foundry
Priority date: 1946-09-23
Filing date: 1946-09-23
Publication date: 1951-01-30
Anticipated expiration: 1968-01-30

Description

1951 J. w. JUPPENLATZ 2,539,525

APPARATUS FOR CASTING METAL RODS Filed Sept. 25, 1946 M wi h ATTORNEYS Patented Jan. 30, 1951 APPARATUS FOR CASTING METAL RODS John W. J uppenlatz, Lebanon, Pa., assignor to Lebanon Steel Foundry, Lebanon, Pa., a corpo-' ration of Pennsylvania Application September 23, 1946, Serial No. 698,766

1 Claim. 1

This invention relates to apparatus for making metal rods of small diameter. In particular, it relates to the manufacture of welding rods or electrodes from alloys which are difficult to manufacture into such rods by conventional methods. For example, complex high melting point alloys 01' the corrosion and heat resistant type containing carbon, manganese, silicon, chromium, nickel, molybdenum, copper, and iron, among other ingredients, may be either diillcult or impossible to roll or hot work. Casting such alloys into small diameter rods in sand molds produces rods of non-uniform size and surface, which are difficult to reproduce, and which are undesirable in certain applications such as electric welding. By the present invention rods of these difficultly handled alloys may be made with ease in uniform size and shape and may be uniformly reproduced. Rods of other alloys of lower melting point and less complexity may also be produced, as will be understood.

Broadly speaking, the invention consists in casting the metal rods in one or more tubes of refractory material, and more particularly comprises forcing metal in molten form to flow into upstanding tubes of given lengths and automatically stopping the flow of the molten metal before it overflows the tubes. The flow of the molten metal may be stopped by rendering ineffective the force causing it to flow, and the molten metal itself may be active or cooperative in rendering this force ineffective. The tubes and metal may then be cooled, and after the metal has solidified, the tubes may be removed and the metal rods recovered.

An object of the invention is to provide apparatus formaking metal rods from complex alloys otherwise difiicult to form into rods. Another object of the invention is to provide apparatus for simplifying the production of metal rods such as welding rods and electrodes. Other objects and advantages will appear hereinafter.

The invention may be better understood by referring to the accompanying drawings in which is shown a preferred embodiment of the invention and in which:

Fig. 1 is a plan view of a holder for the refractory tubes;

Fig. 2 is a side view of the holder of Fig. 1;

Fig. 3 is a vertical section of an apparatus diagrammatically disclosing a preferred form of the invention and taken along the line 33 of the holder of Fig. 1; and

Fig. 4 is a partial view of the upper end of a metal rod made according to the invention.

In the apparatus diagrammatically illustrated in Fig. 3 a tube holder III is shown positioned within a cylindrically shaped housing member or header II. The latter is recessed, as at l2, to receive the holder, a gasket l3 being interposed between the holder and a shoulder I4 of the housing. On its lower side the holder is not flush 2 with the walls of the housing but extends below them to a certain extent, whereby it may be tightly clamped to the housing by clamps l5 and I6. Holder It comprises an upper plate H, a lower plate l8, both of which, like the housing, may be made of metal or other suitable material, and an intermediate plate l9 made of any suitable resilient heat resistant material. The plates may be held together in any desired way, as by

bolts

20, 2|. The holder has a number of holes 22 extending therethrough for receiving the re-- fractory tubes 23, the tubes being gripped and. supported in the holes by the resilient material IS. The tubes are readily attachable to the holder by working them through the holes, as by twisting and turning and by exerting a slight force upon them.

As shown in Fig. 3, the upper ends of tubes 23 extend a little distance above holder l0 into the housing chamber 24. The lower ends of the tubes extend into a source of molten metal 25 and are immersed therein sufficiently to cover the openings and a small portion of the walls of the tubes. The molten metal may be of any composition for casting into the form of the desired rods. It is held in a suitable container or bath 26, which is exposed to the atmosphere, and kept molten by well known means not shown.

Means are provided for forcing the molten metal into the tubes, and in a preferred form such means may comprise low pressure produc-' ing means, such as the vacuum pump30, driven by motor 3|, and suitably connected to the housing chamber 24 and the upper ends of tubes 23 through

conduits

32 and 33, valve 34, and the opening 35 in housing II. The conduits, chamber and valve serve to place the molten metal in the lower ends of tubes 23 in communication with the vacuum pump, and along with the tubes themselves they provide a passageway from the molten metal to the pump. When this passageway is exhausted by the pump, the molten metal will be forced into the tubes by the pressure of the atmosphere on the exposed surfaceof the metal in bath 26. Means are also provided for rendering ineffective the forcing means or pump when the level of molten metal in the tubes reaches a desired height, preferably before the metal overflows the tops of the tubes. According to the invention, such means are responsive to the flow of molten metal and, more particularly, to contact with the same. In one form, and as is preferred, such means serve to shut ofl or obstruct the passageway extending from the pump to the molten metal independently of valve 34, as by freezing the molten metal in the tubes. Said means may comprise headed pins or inserts 40 of suitable length resting on the ends of the tubes and loosely suspended within the same. Desirably such pins may be made of metal of the same composition as the metal in bath 26. Upon contact with pins 40 the molten metal ome;

is solidified thereto, thereby substantially interrupting communication between the molten metal and the pump, rendering the pump ineffective so far as concerns any further movement of molten metal from the bath into the tubes.

In applying the apparatus to the manufacture of metal rods, one or more refractory tubes are supported in holder [0, and the latter is clamped into position in housing I I. Then the lower ends of the tubes are immersed in the molten metal bath, either the bath being movable towards the tubes or the holder assembly being movable towards the bath. In the latter case,

conduits

32 and 33 are made of flexible material to permit movement of the holder assembly. With valve 34 open, the vacuum pump may be started up, thus causing the molten metal to rise in the tubes or if the vacuum is on, the valve 34 can be opened, whereupon the metal will rise in the tubes. One of the first effects of the application of vacuum is that pins 40 are drawn out of the tubes with such force that they strike the under side of wall 4| of housing II. A screen 42 is provided to pre-- vent the pins from entering opening 35 and conduit 32. As shown, the distance between the tops of the tubes and the under side of wall it is such that only a relatively small length of the pins is drawn out of the tubes. After the vacuum has been eflected, the pins may assumea position such as is indicated by pin 43. Movement of the molten metal in the tubes is rapid, and upon coming into contact with pins 40 the metal freezes at the point of contact to both the pins and the walls of the tubes, filling the entire cross-sectional area of the latter and blocking any further rise of metal. As will be understood, the molten metal makes contact with the pins when the latter are in a position similar to that of pin 43. Columns of metal are thus formed in the tubes and rapidly freeze. Valve 34 may then be closed by any appropriate means and the tubes removed from the bath and cooled. The cast shapes may then be removed from the tubes. The upper end of one of the rods, designated 44, is illustrated in Fig. 4, showing how the metalis united to pin 40. The pin end of the rod may, of course, be cut oif prior to using the rod in any particular application.

As stated, the metal from which the rods are prepared may be of any suitable composition, but the invention is particularly applicable in providing rods of high melting point alloys which are difficult to handle by conventional methods. By way of example, the composition of some rods produced according to the invention may be set forth as follows: I

1 Rod No. 4 also contained tungsten 1.2%, titanium 0.4%,columbium 0.47 and nitrogen 0.15%.

' Rod 0. 5 also contained graphite 2%.

- file of this patent:

The alloy of rod No. 1 is very diflicult to roll, while that of No. 5 can neither be rolled nor hot worked. The alloys of rod Nos. 3 and 4 are not readily rolled.

The tubes may be of any generally suitable refractory material. Tubes 01 glass, quartz, porcelain, and various ceramic materials may be used. Tubes made of glass have been found to be particularly satisfactory, preferably low alkali glass of the boro-silicate type such as Pyrex. Such tubes may vary in thickness, for example, from about 3*, inch or less to about 1 or V inch or more, and may produce rods ranging, in diameter, from about to 1 inch, and in length, from about 12 to 30 inches, more or less. Preferably, the refractory material should be removable from the cast rod, and for this purpose the refractory may be sufiiciently brittle to enable it to be shattered without damage to the rod.

The average vacuum employed in the apparatus is subject to variation, depending in part upon the fluidity of the molten metal and in part upon the length of rod sought to be made. Vacuum values between about 20 to 29 inches of mercury are generally useful, although lower or higher values may be employed where necessary.

It willbe understood that the invention as described represents a selected embodiment and is capable of various modifications within the scope thereof.

In the light of the foregoing description, the following is claimed:

Apparatus for casting metal rods which comprises a holder for molten metal, a plurality of upstanding refractory tubes having their lower ends immersed in molten metal when contained in said holder, means connected to the upper ends of said tubes for producing subatmospheric pressure, a metal pin seated on the upper end of each tube and loosely extending downwardly therein, said subatmospheric pressure producing means being adapted to draw said pins ofi the ends of the tubes and then to exhaust the tubes sufficiently to allow the molten metal to rise therein, and means adjacent the upper ends of the tubes for preventing said pins from passing entirely out of said tubes, said pins serving to freeze the molten metal in the tubes at a point below the upper ends thereof upon contact with the molten metal.

JOHN W. JUPPENLATZ.

REFERENCES CITED The following references are of record in the UNITED STATES PATENTS FOREIGN PATENTS Country Date Great Britain of 1825 France Nov. 8, 1917 Number Number.