The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 10, 1996
Filed:
Apr. 20, 1995
Curtis R Stidham, Parma, OH (US);
Robert McPherson, Jr, Aurora, OH (US);
Thomas M Dedo, Independence, OH (US);
Erico International Corporation, Solon, OH (US);
Abstract
An exothermic welding apparatus and method uses a crucible which can be used with a variety of exothermic weld metal material volumes to produce welds of different sizes while maintaining the desired diameter to height ratio for each volume of exothermic material. In one embodiment, the crucible includes a double or two stage cavity. The crucible includes a somewhat smaller lower stage which reduces the diameter for smaller volumes. This lower stage may have two disk seats to isolate the two stages from the tap hole. A disk seat is provided for a larger disk between the two stages. The crucible may include a volume of exothermic material in the smaller lower chamber, the larger upper chamber, or a combination of both. In a triple stage embodiment, a wider variety of exothermic material volumes or masses may be accommodated, all while maintaining the desired diameter to height ratio for each charge. Although the desired ratio is approximately one, the ratio range should be maintained from about 0.5 to about 1.4, and no more than 2. The invention enables crucibles and molds to be used more economically and efficiently with the same crucible being useful in a wide variety and sizes of connections, all with a quality low impedance weld.