| 摘要 |
PROBLEM TO BE SOLVED: To avoid problems such as improper mismatch of cross section shape produced between both facing ends of the yoke and the neck tube of a glass funnel for a cathode-ray tube when they are welded, and worsening of the appearance of the periphery of the welded and sealed part, local defective welding and sealing, and the problem of welding and sealing strength. SOLUTION: In an end region on a small-opening end 4 side of the square yoke portion 5 of the funnel 1, an extended portion 10 is provided whose external surface 8 and inner surface 9 dimensions in their radial directions gradually increase uniformly extending over the whole periphery, as they approach a large-opening end 6 side. The extended portion 10 is formed making the end face 4a of the small-opening end 4 starting end. The contour lines of the external surface 8 and the internal surface 9 of the extended portion 10 in its cross section containing a tube axis Z, are formed with individual arcs having the centers of curvature A, B respectively in regions which are to the peripheral sides of the surfaces and more to the neck tube 3 side than the end surface 4a of the opening end 4. COPYRIGHT: (C)2005,JPO&NCIPI
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