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:
Apr. 17, 1990
Filed:
Oct. 14, 1988
Takashi Yamade, Hitachi, JP;
Seishi Watahiki, Katsuta, JP;
Yasuzi Sakuma, Hitachi, JP;
Masayoshi Yamaguchi, Hitachi, JP;
Shinichi Kurita, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A plasma welding method has successive steps including pre-heating of members to be welded, tack welding of the members for tentatively fixing these members, keyhole welding for completely welding the members to each other, and finish padding. These steps are automatically conducted by a single plasma welding apparatus operative in accordance with a programmed sequence including data concerning the optimum conditions of operation in each step in relation to the conditions such as sizes and materials of the members to be welded. The apparatus has a welding torch, a welding head on which the welding torch is mounted for rotation, a controller adapted for storing the optimum welding conditions for successive steps of the welding process in relation to the conditions of the members to be welded, a power supply system for transmitting welding current and welding speed signal to the welding head in accordance with a command provided by the controller, and a gas supply system for supplying a plasma gas at a rate determined in accordance with a command from the controller.