Metal founding – Means to directly apply electrical or wave energy to work – In continuous casting apparatus
Reexamination Certificate
1999-06-11
2001-08-14
Lin, Kuang Y. (Department: 1722)
Metal founding
Means to directly apply electrical or wave energy to work
In continuous casting apparatus
C164S514000, C373S100000
Reexamination Certificate
active
06273179
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed, generally, to continuous metal casting, and more particularly to a method and apparatus for electrode or metal ingot casting.
2. Description of the Invention Background
Over the years, a variety of methods and improvements have been developed for casting metal electrodes and ingots. An electrode essentially comprises a solid cast metal block that is formed to be remelted and cast into an ingot, or into a certain geometric form. To accomplish the remelting of the electrode, an appropriate amount of electrical current is applied to the electrode utilizing known techniques and process controls. Thus, an electrode is essentially an intermediate product used in metal casting processes and an ingot is a finished product that is usually subsequently subject to mechanical deformation, such as forging or rolling.
Metal electrodes may be formed utilizing a variety of casting processes. For example, electrodes may be continuously casted in a vertically oriented process wherein the electrode is cast into a stationary mold from plasma arc, electron beam, vacuum induction, skull induction, skull or ac furnaces.
FIGS. 1-4
illustrate the conventional dovetail assembly and electrode forming process in vertical continuous casting. Conventional continuous casting of steel and titanium electrode melting in electron beam, plasma arc or skull furnaces typically uses a supporting mechanism, such as a cylindrical block
2
, that is machined to include a dovetail
3
. The cylindrical block
2
is detachably engaged to side wall
4
to form a vertical continuous casting vessel
5
.
During vertical continuous casting, molten metal is introduced into, and fills, the vessel
5
. Because the cylindrical block
2
is made from a conductive metal, the cylindrical block
2
conducts heat away from the molten mass, and thereby encourages solidification near the bottom of the vessel
5
. As is common in continuous casting, the cylindrical block
2
is detached from the side wall
4
and is mechanically moved downward to grow the electrode column length. As the cylindrical block
2
moves downward, molten metal is continually added into the vessel
5
to maintain the liquid level of the molten metal at the top of the side wall
4
. Typically, a heat source is used near the top of the vessel
5
to provide additional heat in this area for maintaining the molten mass in the molten state and preventing premature solidification. The dovetail
3
locks the electrode to the cylindrical block
2
, as the block
2
moves downward. Through this process, for example, an electrode of approximately 15,000-25,000 pounds may be produced. The electrode is then laterally removed from the dovetail
3
and released from the cylindrical block for further processing.
As the cylindrical block
2
moves downward, however, streaks of molten metal may run down along the surface of the electrode and form icicle-like formations or “rundowns” over the sides of the dovetail
3
. These “rundowns” can act as a latch that prevents removal of the electrode from the cylindrical block
2
. Accordingly, these “rundowns” must be chiseled from the dovetail
3
so that the electrode can be withdrawn from the block
2
.
Furthermore, such process generally provides a cast electrode that has a relatively uneven surface that is not well suited for uniform adhesion to other flat surfaces, such as a conducting solid cylinder which is used to introduce current into the electrode during the re-melting process. Thus, during subsequent vacuum arc or electroslag re-melting, introduction of current into or through the cast surface on many occasions causes arcing that results in damage to the re-melting equipment. A massive plunge/stub must be welded to one end of the electrode. The plunge/stub has a smooth surface and is used both to support the electrode weight and to introduce current into it.
FIG. 4
illustrates the conventional electrode assembly wherein an electrode
6
is welded to the solid conducting stub
7
for subsequent re-melting of the electrode through the application of a current thereto through the conducting stub
7
.
The need to mechanically remove the “rundowns” from the cylindrical block and the additional welding processes add a significant amount of time and cost to the continuous casting process. Accordingly, a continuous casting locking mechanism and electrode assembly is needed that eliminates these additional process steps to increase manufacturing time and efficiency.
BRIEF SUMMARY OF THE INVENTION
The present invention addresses the above-mentioned needs by providing a stub locking mechanism and a modification to the existing process for electrode or ingot formation.
In one form of the invention, the locking assembly includes a locking member, a stub, and a support member. The locking member removably extends through the support member and at least a portion of the stub.
The present invention also provides an apparatus for manipulating an electrode, comprising a stub, an elongated yoke, and a conducting tube. The stub protrudes from the electrode affixed thereto. The elongated yoke is removably pinned to the stub. The current conducting tube is hollow and extends around the elongated yoke and in electrical contact with the stub.
The present invention also provides a method of casting an electrode in a mold cavity. A stub is inserted into the mold cavity such that at least a portion of the stub protrudes into the cavity. The stub is locked to a bottom support member and molten material is introduced into the cavity.
The present invention includes a new device for gripping an electrode, positioning the electrode in a re-melting furnace, supporting the electrode during re-melting, and conducting and introducing electric current required for re-melting into the electrode. The present invention also increases manufacturing efficiency by providing an assembly and associated method that eliminates the problems associated with “rundowns,” such as, for example, electrode disengagement from the support member, and the need for welding together the components of the assembly.
REFERENCES:
patent: 3650311 (1972-03-01), Fritsche
patent: 3752216 (1973-08-01), Fritsche
patent: 4498521 (1985-02-01), Takeda et al.
patent: 4567935 (1986-02-01), Takeda et al.
patent: 402867 (1924-09-01), None
patent: 134604 (1979-03-01), None
patent: 3629043 A1 (1987-07-01), None
patent: 3629043 (1987-07-01), None
patent: 114309 (1954-10-01), None
patent: 0 114 309 A1 (1984-08-01), None
patent: 1075052 (1954-10-01), None
Geltser Ilia S.
Tyson Mitchell D.
ATI Properties Inc.
Lin Kuang Y.
Viccaro P. J.
LandOfFree
Method and apparatus for metal electrode or ingot casting does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for metal electrode or ingot casting, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for metal electrode or ingot casting will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2459958