Rieter

Changes in the conditions

Index

The forces FF and FB and the angle δ are subject to substantial variation during one stroke of the ring rail. This implies corresponding variation in force FL . The point at which the yarn passes through the traveler also varies, however, with the magnitude of the tensile component FL, and the angle of attack. When the ring rail is at the top of its stroke (small cop diameter, Fig. 96 a)), yarn tension is high, the yarn acts on the traveler at a position only slightly above the ring, and it draws the free end of the traveler upwards on the left-hand side.

The traveler straightens up. When the ring rail moves down, the tensile forces are reduced, the balloon widens out, and the yarn slips towards the middle of the curve in the traveler. The free end of the traveler tilts slowly downwards on the left-hand side.

In addition to these tilting movements, the traveler also performs a so-called rolling motion. If the yarn moves upwards in the traveler (Fig. 97 b)), the point of attack of the yarn on the traveler moves away from the contact surface with the ring. The yarn acts on the upper portion of the curve in the traveler, which is thereby drawn out of the vertical with an inclination to the left. In the reverse effect, when the yarn in the traveler approaches the ring more closely during upward movement of the ring rail, i.e. as the yarn moves downwards relative to the traveler, the latter straightens up again (Fig. 97 a)). This variability in the movement of the traveler is not good in terms of friction conditions; on the other hand, the traveler needs this freedom to enable it to adapt to the varying forces and to take up impact.

Fig. 96a) – Raising and lowering of the traveler raising, caused by the greater force FL

Fig. 96b) – Raising and lowering of the traveler lowering, caused by the reduced force FL

Fig. 97 – Varying inclination of the traveler on the ring; a) upright; b) inclined