| 摘要 |
PURPOSE: To maintain a fixed point in a stationary state with respect to a measurement axis even when a part of a device is expanded/contracted because of temperature fluctuation by disposing a temperature insensitive body having first and second faces arranged in the measurement axis in a second virtual face and linking a centering mechanism with the second face and a slide support. CONSTITUTION: An extended temperature insensitive body 32 is provided so as to approach a base 12 in a second virtual vertical face in the lower sides of slides 16 and 24, a first face 32a is provided in a measurement axis MA, and the body 32 is extended by traversing the base 12 in an upper position. Here, a second face 32b is linked with a vertical centering mechanism 38 via a second socket 36. The centering mechanism 38 is extended upward of the base 12 and arranged side by side with an X axis slide support 22, a reference point RP is set in its upper end and this is positioned in the same plane as the second face 32b of the insensitive body 32. This arrangement is maintained for the thermal expansion time of a lace 10, and the insensitive body 32 serves to set a relationship between the reference point RP and the measurement axis MA. |
