Abstract: To permit ready reversal of rotation of a yarn supply drum, and to positively guide yarn being drawn off the drum, a thread guide element in form of a finger is located laterally offset with respect to the axis of rotation of the storage drum, extending essentially in a direction transverse to a tangential plane at the pull-off point of the yarn, the lateral offset being changeable to either side of the pull-off point to accomodate different directions of rotation of the drum, with simple change-over of the yarn guide finger, for example by re-positioning a mounting plate to extend either towards the left or the right from a support arm.

Abstract: A rotatable storage drum is connected for rotation to have yarn wound thereon. The pull-off position of the yarn is controlled by a yarn guide element which is a pin extending into the path of the yarn and forming an acute angle with a plane parallel to the axis of rotation of the drum. The pin is located on a rotatable disk so that the point of the acute angle can face either forwardly or rearwardly of the drum, so that the thread guide element can guide the yarn regardless of the direction of rotation of the drum and without tangling of the yarn if the guide element is set incorrectly with respect to the direction of rotation thereof; the element can also be set in an intermediate position in which it is ineffective with respect to the pull-off position, so that the drum can be used as a demand-storage supply drum, rotatable in either direction without structural modification of the overall apparatus.