Claims
- 1. A method of producing a male block of a resinous dome-forming mold, the male block having a dome-shaped protrusion which includes a hemispherical section that is just half a sphere and a cylindrical section continuing from an end of the hemispherical section, comprising the steps of:preparing a spherical block having a spherical surface ranging over at least more than half a sphere; rotating said spherical block around an axis passing through the center of said spherical block; grinding an area of the spherical surface of said spherical block ranging over more than 180° from a top of the spherical surface through which the axis of rotation passes to a circumference thereof using a grindstone with a curved surface having substantially the same radius of curvature as that of the hemispherical section of the male block; cutting off a grounded portion of said spherical block to complete the hemispherical section of the male block; preparing a block on which the cylindrical section of the male block is formed; and joining the cylindrical section to the hemispherical section to complete the male block.
Priority Claims (1)
Number |
Date |
Country |
Kind |
10-95629 |
Apr 1998 |
JP |
|
Parent Case Info
This application is a division of Ser. No. 09/274,295 filed Mar. 23, 1999 now U.S. Pat. No. 6,317,955.
US Referenced Citations (30)
Foreign Referenced Citations (1)
Number |
Date |
Country |
5-104642 |
Apr 1993 |
JP |