| 摘要 |
{PG,1 In a web feed apparatus wherein a section of the web is maintained at a higher tension while accurately metering the feed of the web at a relatively lower tension, and wherein means are provided to isolate the low tension metering function from the higher tension section by anterior snubbing rolls, the web tension is controlled by modifying the gain produced by the snubbing rolls and feeding back any increase in tension from the lower web tension level to the higher web tension level. Such a gain is modified by controlling the total angle of wrap of the web about the snubbing rolls, or by varying the coefficient of friction between the web and the snubbing rolls.
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