| 摘要 |
PURPOSE:To prevent the damage of a long material, by separating the surface of the winding and an air arm, which faces the outer surface of an extending roll or a winding roll of the long material, and detecting the diameter of the winding. CONSTITUTION:A nozzle 4b is provided at the tip of the air arm 4. The nozzle 4b faces the outer surface of the roll around which the long material 1 is wound with a contactless state maintained. The amount of rotation of a supporting point 4a of the air arm 4 is transduced into an electric signal by a potentiometer 3, and the diameter of the winding on the roll is detected. |
