| 摘要 |
PURPOSE:To obtain the length measuring device characterized by small thermal expansion and excellent wear resistance by constituting the main bodies of a main scale and a vernier scale by ceramics. CONSTITUTION:The main bodies of the main scale 1 and the vernier scale of vernier calipers are formed by a highly pure fine ceramic material. A recessed groove 5 is provided in the surface of the main scale 1 in the axial direction, and main scale graduation 6 comprising an electric conductor is provided in said groove 5 by a means of printed wiring and the like, by utilizing insulating property of ceramics. Similar vernier scale graduation 7 comprising an electric conductor is provided on the vernier scale with respect to the main scale graduation 6. The graduation interval of said vernier graduation 7 is the same as that of well known vernier calipers. The contact of the main scale graduation 6 and the vernier scale graduation is electrically read, and the value is displayed on a digital display part 8 on the vernier scale. |
