Rieter

Forming the base

Index

Fig. 48 – Engagement of cam (N) in the winding mechanism

The base is convex in order to accommodate as much yarn as possible on the  cop (Fig. 44, A). This convex shape results partly automatically from the specific type of winding, but is also reinforced to some extent by an auxiliary mechanical device, known as a cam, cog, deflector or also by other names (Fig. 48, N).

As we have already stated, the raising and lowering of ring rail (R) results from the fact that lever (H) of cam (E) moves up and down and disc (a) is thus continuously turned to the left and right. Cam (N) attached to this disc (a) projects over the periphery of disc (a) and thus increases the diameter of the disc at this point.
When winding on the cop commences, disc (a) is in a position in which the cam deflects chain (K) to some degree, as shown in Fig. 48. As a result of this deflection, part of the elongation of the chain arising from the rise of lever (H) is not passed on to the ring rail, but is lost as deflection at N. The ring rail traverse no longer corresponds to the specification, it is smaller. Since the yarn delivery length per traverse remains unchanged, the bulk per layer is increased, which results in the convex shape referred to above.
If chain winding drum (T) is now turned continuously to the left in small amounts by the winding ratchet wheel in the further course of spinning, and chain (K) is wound up on this disc and thus continuously shortened, disc (a) also turns to the right in equally small amounts, the cam is increasingly less engaged, so that finally the entire elongation of the chain is passed on to the ring rail; the cop is built up normally.