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. 27, 1982
Filed:
Mar. 19, 1980
Applicant:
Inventors:
Hisanao Kita, Ibaraki, JP;
Yoshinori Karatsu, Ibaraki, JP;
Takamitsu Nakazaki, Ibaraki, JP;
Yoji Akutsu, Ibaraki, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K / ;
U.S. Cl.
CPC ...
2191 / ; 2191 / ; 2191 / ; 2191 / ;
Abstract
A vacuum chamber for welding in which to place a workpiece is hermetically connected to a vacuum chamber for an electron beam gun in which to place an electron beam gun, and the former is kept at a vacuum of 1.times.10.sup.-4 Torr while the latter, at a vacuum of 1.times.10.sup.-6 Torr. The distance between the electron beam gun and the surface of the workpiece is made greater than the mean free path of gas molecules and metal vapor molecules generated in treating, e.g., 1.85 m. Two focusing coils are arranged to prevent the expansion of the electron beams.