Device for control the yarn tension of a yarn being drawn of a bobbin located on a bobbin holder for a leno selvage device

摘要

Yarn (6) for a twist selvedge is supplied from a bobbin (5) that can rotate on a carrier against the restraint of a brake drum (1) with a hinged, adjustably spring-loaded brake shoe (14). The action of the brake is controlled by a flexible lever arm (20) that has an eyelet (21) at its end through which the yarn (6) is drawn off. The fulcrum (11) of the brake shoe housing is along a tangent (12) to the brake drum (1) drawn at the center line (13) of the brake shoe (14). The ratio of the lever action between lever arm (H2) and brake shoe (H1) is between 9 and 12 to 1. The diameter of the brake drum (1) is about three times that of a full bobbin (5).