Method and combination for winding strands of web material having varying thicknesses on a take-up drum

A method for eliminating slack in one or more of a plurality of strands of web material formed by slitting a web of sheet material which is unwound from a feed roll, where the sheet material has a non-uniform lateral thickness and the strands are being wound into coils on an expansible and contractable take-up drum, comprising the steps of:

• (a) winding the strands onto the drum in its expanded condition at the same rate the sheet material is being fed from the feed roll and maintaining a substantially uniform tension in the portions of the strands downstream from the slitting operation as the strands are being wound;
• (b) forming a fixed diameter loop from each strand around said drum, the inner surface of the loops conforming substantially in size and shape to the outer surface of the drum in its expanded condition;
• (c) reducing the outer diameter of the drum an amount where frictional contact between the loop and drum will cause the loop to rotate with the drum, but which will cause the loop to slip relative to the drum when a predetermined tension in the strands is reached which is greater than said uniform tension;
• and
• (d) reducing the rate the web material is being fed from the feed roll relative to the rate the strands are being wound onto the drum.

A combination for eliminating slack in one or more of a plurality of strands of web material of different thicknesses as the strands are being wound onto a take-up drum, comprising:

• (a) means for connecting and disconnecting a portion of each strand to the drum;
• (b) means for rotating the drum for winding the strands onto the drum;
• (c) means for connecting a portion of each strand to a previously wound portion of the same strand for forming a plurality of fixed diameter loops about the drum, the portion of each strand adjacent to the drum substantially conforming in size and shape to the outer surface of the drum;
• (d) means for maintaining a substantially uniform tension in said strands as they are wound onto the drum;
• (e) means for selectively reducing the outer diameter of the drum an amount sufficient to cause the loops to slip relative to the drum when the drum is rotated and a predetermined tension greater than said uniform tension is reached in the strands, the frictional force between the strands and drum causing the loops to rotate with the drum until said predetermined tension is reached;
• and
• (f) means for regulating the rate the strands are wound onto the drum relative to the rate at which the strands are being fed to the drum so that winding rate can be adjusted to be greater than the feed rate.