| 摘要 |
PURPOSE:To extend the replacement period of web, by providing a means for detecting the external diameter of at least one of a pay-off and a take-up shaft, and controlling the winding amount of the web on the basis of its detection signal. CONSTITUTION:A rotatable roll 8 is provided in contact with the outer circumference of the take-up shaft 4 atop of an arm 7 energized counterclockwise by a spring supported pivotally by a shaft 10 associated with the input part of a potentiometer 9. The web is wound around the external diameter part of the take-up shaft 4 by a motor which drives the take-up shaft 4 as shown by an aroow A, but the motion of an arm 7 which oscillates from a solid-line position to a two-dot chain line position while follwoing up an increase in the external diameter of the take-up shaft 4 is detected by the potentiometer 9 to reduce the rotating amount of the take-up shaft 4 according to the increase in the external diameter of the take-up shaft 4, winding the web by a specific amount. |
