Rieter

Lifter motion

Index

In the package, each turn must be laid next to its neighbors. For this purpose, the lay-on point must continually be moved. This can be brought about only by raising and lowering the bobbins. This requirement cannot be met by raising and lowering the flyers, because then the unsupported roving length (from drafting arrangement to flyer top, see  Fig. 3) would vary correspondingly and the angle of departure from the drafting arrangement and of approach to the flyer top would change continuously. The winding point must be shifted by moving the bobbins, which are supported on a movable rail for this purpose. The necessary raising and lowering can be carried out by means of several racks attached to the rail (Fig. 23). Some manufacturers have mounted the bobbin rail on a lever and move the rail by moving that lever up and down (Fig. 24).

The individual coils of the bobbin must be laid closely adjacent to each other, not only in the first layer but also in all subsequent layers. However, since the package diameter is steadily increasing, the lift speed must be reduced by a small amount after each completed layer. As can be seen from Fig. 24, the lift drive is also transmitted via the cone transmission (as for the  bobbin drive), but not via the differential.

In addition, a reversing drive must be provided so that the bobbin rail is alternately raised and lowered.

Fig. 23 – Lifter motion with racks (a)

Fig. 24 – Lifter motion with levers (b)