| 摘要 |
PURPOSE:To permit the control of tension by using a simple apparatus by selecting the feed speed by using a rotary drum and a transportation member so that a slack is generated between a restraining member and the transportation member and adjusting the feed speed so that the amount of slack in a slack part does not exceed a set value. CONSTITUTION:A web 1 consisting of an original print sent-out from a print making part is transported at a speed of V1 by a transportation member 2 consisting of the upper and lower nipping rollers in pairs and is nipped and restrained by a restraining member 3 consisting of a pair of nipping rollers set in the vertical direction, and the top edge of the web is held onto a rotary drum 4 revolved at a speed of V2 by a clamper 6 and then taken-up. In this case, V1> V2 is to be fulfilled, and a slack is generated on the web 1 between the transportation member 2 and the restraining member 3. In order to detect the slack amount, a detection roller 5 is attached onto the web 1, and when the slack amount increases to reach the max. set amount of slack, the revolution speed of the rotary drum 1 is switched to V3 (>V1). |
