DRUM FOR WINDING UP MATERIAL WHICH IS BEING DRAWN

摘要

A drum for winding optical fibres consists of an envelope of an airtight plastic material having a certain degree of resiliency. The envelope defines an internal chamber maintained at a pressure somewhat higher than ambient, presents centering recesses permitting engagement with a drive spindle, and is equipped with a valve for varying the pressure inside the chamber so as to adjust the tension in the wound fibre.