Rieter

The formation of the base

Index

Fig. 87 – The formation of the curvature at the cop base

The creation of the typical cop form is explained as follows by Johannsen and Walz  [20].

The heart-shaped cam and the delivery cylinder are coupled together by the drive gearing. Thus the quantity delivered for each revolution of the cam, and hence per yarn double layer, is always the same. The volumes of the individual double layers are therefore also equal.

Deposition of double layers on the tube begins with a small average layer diameter, d1 (Fig. 87). The average diameter increases gradually with each newly deposited layer. With constant layer volume, this can have only one result, namely a continual reduction of the layer width from b1 to b2 to b3, and so on.

Since the ring rail is also raised by a constant amount h after each deposited layer, it follows that a curve, rather than a straight line, arises automatically in the base portion, at the bottom.