| 摘要 |
PURPOSE:To make a large-sized lead spring usable and a shadow mask deviable as much as a proper quantity to the side of a phosphor screen surface, by setting a welding seam running along in a longitudinal direction of the bimetal type leaf spring to such length as not reached to a fixed range of the said spring. CONSTITUTION:A bimetal type lead spring 10 is provided with the fixed range 12 fixed, at a welding point 11, to a side wall outer surface of a mask frame 3 installing a shadow mask 2 at one end edge in the longitudinal direction, having a hole 14 at a tip end of the remaining movable range 13. And, a welding seam 17 joining a high expansion coefficient metal 15 and a low expansion coefficient metal 16 together should be set to such length as not reached to the fixed range 12, while thermal operating length 18 of the lead spring 10 is set to be shorter than mechanical operating length 19. Thus, length of the welding seam 17 is optionally changed whereby such a lead spring that has the specified heat indication characteristic is secured without altering a combination of both these metals 15 and 16 so that the shadow mast is deviable as much as a proper quantity to the side of a phosphor screen surface.
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