| 摘要 |
1,191,017. Special processes. GENERAL ELECTRIC CO. 16 May, 1967 [19 Aug., 1966], No. 22641/67. Heading B3T. [Also in Division H1] A doming die of type H or type V biradial contour is generated on a lathe for preparing a shadow mask for a colour TV cathode-ray display tube (see Division H1). The two types may each satisfy horizontal and vertical sweep requirements but produce a different geometry along the diagonals. In the type H biradial construction the cutting tool is swung about point O of distance R 4 from point M and along the major axis from the mask centre to point N as the mask die is rotated about the horizontal lathe axis. In the type V biradial construction, the cutting tool is swung about point O of distance R v from point M along the arc MN of the minor axis as the mask die is rotated about the vertical lathe axis. The type H configuration is preferred when the major axis curvature is not a simple circular arc and the type V may be used when only lathes of minimal swing are available. |
