Device for flying roll-changing in an unwinding station under constant web tension

摘要

An unwinding station for webs, especially paper webs, each with a bearing for a primary winding (3) and a secondary winding as well as with means for flying sticking the web start of the primary winding of the web end of the secondary winding comprises a driven or braked primary winding (3) and one with connected to a control device (11) control unit of the drive unit (10). According to the invention it is provided that the control device (11) comprises a speed control means which controls the drive unit to a speed n _b, such that the rotational speed of the primary winding is greater than the speed of the running from the secondary winding path, and the speed control means by reversal on generator operation the rotational speed of the primary coil of the rotational speed to a rotational speed n _b n _synch down regulates corresponding to the flow speed of the web from the secondary winding. Furthermore, the control means (11) controls the descent to the rotational speed n _synch such that the braking force corresponds to the time of the transfer of the web from the primary winding of the force which is required to maintain the web tension. In addition, a web tension control device (13) according to the invention provided, which receives the web tension after the adhesion maintained.