| 摘要 |
A machine for the electron-beam external butt welding of tubes comprises n radially directed electron guns (50 to 55) arranged on a fixed support, each gun having local means for the displacement of the electron beam emitted thereby to cause said electron beam to sweep a different area of the annular surface (1) of contact of the tubes, each area extending over a fraction of the annular surface at least equal to 1/n. The displacement means may comprise means for limited translatory or pivotal displacement of the respective gun and/or means for deflection of the beam of the gun. As described, the guns are mounted on the wall (19) of a vacuum chamber. For translatory displacement, each gun is mounted on a plate (26, Fig. 3) which slides sealingly over an opening in the wall (19). For pivotal displacement, each gun is mounted in an opening in the wall (19) with a bellows (36, Fig. 4) extending between the wall and gun. <IMAGE> |
