| 摘要 |
<p>1331342 Welding by fusion UNION CAR BIDE CORP 30 April 1971 [1 May 1970] 12376/71 Heading B3R [Also in Division H1 An electron beam welding apparatus comprises a gun chamber G, Fig. 1, adapted to be secured to the work chamber C and provided with an elongate opening covered by a flexible barrier through which the electron gun extends. In Fig. 1 the barrier comprises a continuous loop M with the electron gun E sealed through an aperture in the lower part 5 of the loop and passing through a slit in the upper part 3 so that it may traverse the length of the opening in the chamber C covered by the loop. The slit may have overlapping lip portions which perform a valve function (Fig. 3, not shown) so that the chambers C and G can be evacuated to 5 microns pressure by a roughing pump connected to chamber C, and the chamber G can be evacuated to 0À1 microns pressure by a diffusion pump. The gun E may be mounted on a bellows attached to the end of the cylindrical portion passing through the loop M (Fig. 4, not shown). In an alternative arrangement, the barrier comprises a strip which may be attached to spring loaded rollers at each end, and such a strip may also perform a valve function (Fig. 5, not shown). In one such arrangement (Fig. 6, not shown) the chamber G is provided with external flanges and a peripheral sealing ring which allow it to be sealed to a co-operating chamber which may be a hollow workpiece or an intermediate pressure chamber disposed between the gun chamber and the work chamber.</p> |
