Method of winding self-supporting bobbin and self-supporting bobbin with cheese package of lower thread for sewing machines

摘要

The yarn was wound from the inner diameter (di1) of the winding coil at a higher initial gear ratio between the speed of the winding bobbin and a traversing cam drum or winding device to achieve a pre-selected diameter for a step change transmission ratio. After reaching a preselected diameter (di2, d.sub.3.n., Di4) of the winding for the step change is abruptly reduced transmission ratio, and the whole interval of increasing the winding diameter to the next step ratio change gear ratio to a small extent continuously increases or decreases the controlled winding for maintaining a constant axial distance between adjacent turns equal to the thickness of the wound yarn. Self-supporting coil cross winding lower thread sewing machine, in which between the inner diameter (di1) of the winding coil and the outer diameter (d.sub.5.n.) winding of the coil is at least one step change after winding ratio . Consecutive yarn turns (30) are in the interval between hopping after winding ratio juxtaposed with zero gap, which is in the interval between hopping after winding ratio maintained continuous increasing or continuous decreasing after winding ratio to a small extent. Step change after winding ratio is caused by a step change of the transmission ratio of the winding device.