| 摘要 |
1,099,328. Etching. PHILIPS' GLOEILAMPENFABRIEKEN N.V. March 31, 1966 [April 3, 1965], No. 14259/66. Heading B6J. A groove pattern is produced on one of the co-operating conical parts of a spiral groove bearing by coating said part with a photosensitive etching resist, by placing in contact with said part a transparent jig having a co-operating conical surface having a required opaque design thereon, exposing the resist to light through the jig, removing the jig, developing, and etching. The design on the jig may be formed by securing thereto a photographic negative. |
