| 摘要 |
<p>An optical system for use in an electron beam welding machine for viewing workpieces mounted within a vacuum chamber from a position outside the chamber, either before or during the welding operation. The optical system includes an automatic motorized means (24) for adjusting the focus of the system to accommodate different electron beam gun to work distances, and simultaneously to automatically adjust the angle with respect to the axis of the electron beam along which the view of the area being welded is to be observed. A transparent disc (22), which may be rotated step by step about its central axis in approximately 30° increments is mounted so that a portion of its surface near its periphery is interposed in the viewing path (21) so as to shield the optical parts of the viewing system from the vapors and radiations which are generated during the electron beam welding process. A means for illuminating only the area on the work surface which is to be viewed (15, 35, 36) is also provided with a similar shielding means.</p> |
