| 摘要 |
PURPOSE:To permit to lap a multitude of curved surfaces almost uniformly by a method wherein alternate streaks are lapped by a tool having a plurality of plate-like bodies with a pitch twice of the same of the protruded and recessed streaks in the forming of a project screen or the like. CONSTITUTION:The lapping tool 9 has a plurality of plate-like bodies 11 of brass or the like on the holder 10 with a pitch twice of the intervals of the curved surfaces 8 of the project screen 6 and the tip ends of the bodies are formed into protruded surfaces 12 corresponding to the curved surfaces 8 while the holder 10 is connected to a supersonic oscillator. The protruded surfaces 12 of the tip ends of the tool 9 are abutted against the curved surfaces 8 in respective areas 6a-6f of the project screen and every second streak are lapped through lapping agent shifting the tool by the pitch of the streak. According to this method, if the difference of working conditions is caused, it may be absorbed in the direction of the width, therefore, the curved surfaces may be lapped almost uniformly as a whole. This lapping process may also be applied to a forming mold. |
