| 摘要 |
The present invention relates to a method for forming a sheet-metal blank (1), in particular for making a cathode tube mask, on a press, according to which the peripheral part of the sheet-metal blank (1) is held over a small width in a peripheral member (30), the central part of the sheet-metal blank (1) is formed, according to a given curvature, by deforming the punch (17) and the die (13) through the action of an upper bearing plate (19), a mechanical force is exerted on localized zones of the clamping member (30), moving closer together the opposite elements of the said clamping member, and at the same time the peripheral zone of the sheet-metal blank (1) is applied and unfurled along the side walls of the punch (17) or of the die (13) by a relative movement of the clamping member (30) with respect to the punch (17) or to the die (13) so as to obtain the final flanged edge. The invention also relates to a cathode tube mask made in accordance with this method.
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