Self-centering sheave for filaments

The combination of at least one filament supply spool mounted to rotate about a filament supply spool axis, from which a filament is drawn and in the process reciprocally traverses the filament supply spool in the direction of the filament supply spool axis, and a self-aligning filament guide, said self-aligning filament guide comprising:

• a bearing plate having a through aperture and associated pulley assembly corresponding to each filament supply spool, each pulley assembly being pivotably mounted in a corresponding aperture in said bearing plate for pivotal motion relative to said bearing plate about an axis perpendicular to said bearing plate, wherein:
• each pulley assembly comprising a bearing disk mounted in its corresponding aperture in said bearing plate for pivotal motion about said axis perpendicular to said bearing plate, said bearing disk including a central opening, an a pulley wheel mounted in the central opening of its bearing disk for rotation about an axis which intersects said axis perpendicular to said bearing plate;
• and
• each pulley assembly is aligned with its corresponding filament supply spool and pivotal in order to follow the traversing motion of the filament from the corresponding filament supply spool.