Rieter

Roving stop motions

Index

Fig. 63 – SKF roving stop motion

If a yarn breaks on a ring spinning machine, the fiber ribbon continues to emerge from the drafting mechanism, usually into the fiber extraction system. However, in poor spinning conditions it often happens that the ribbon wraps around a cylinder or a roller and causes a lap. This in turn can result in damage to the top rollers, aprons, etc., deformation of the bottom roller or simply breaks in neighboring threads. Removing laps is also quite complicated and laborious. It would therefore be desirable to interrupt the flow of fibers at each thread break until piecing is completed. However, the roving would then have to be inserted again automatically.
Roving stop motions can be part of a rotating carriage or individual units for each spinning position. Units in rotating carriages are less expensive, but do not stop immediately in the event of a thread break – as do the individual units – since they first have to find it.

The SKF roving stop motion (which is no longer available for sale) is outlined briefly here on behalf of all other individual units (Fig. 63). The monitoring optics check the threadline. In the event of a thread break, roving feed is interrupted via optical unit 1 and electronics 2 via wedge 3. The table and possibly pivot 4 retain the roving firmly in the break draft zone. After the yarn break has been repaired, wedge 3 is retracted manually by means of roving locking device 5. The roving is delivered and spinning can commence.