| 摘要 |
This invention relates in general to a method and apparatus for welding tubes from a metal sheet which is formed into a tubular configuration with a longitudinally extending slot or welding gap, and which includes sensor means adjacent the slot for accurately positioning a welding device. The welding device comprises an electron beam welder having means associated therewith for shifting the beam or the holder for the beam welder in accordance with the position of the longitudinal slot of the formed tube prior to welding. The position of the beam may be regulated by deflecting it electrostatically or electromagnetically and the feeler or sensor which is associated with the formed slot of the tube is connected either electrically or mechanically for effecting the shifting of the beam. The sensor may comprise a three-pole magnet having windings between adjacent poles and which is oriented over the gap of the tube to be welded and which is connected so that the variations of voltage in the windings caused by the shifting of the gap of the tube which is to be centered in respect to the welding apparatus will provide the necessary control pulse for the shifting of the electron beam for centering it during the welding. The same control may be effected by a mechanical shifting device, by an air deflecting device, or by a mirror operated arrangement.
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