To solve the problems of over-tension or loosening of the yarn caused by the heightening or lowering of a selvage part by disagreement of a reed yarn width and a winding beam width when winding a beam for a loom by a device for winding yarns, especially a beamer.

Conventionally, the regulation of the width of the winding beam and the width of the reed yarn width has been carried out manually by sensing. The over-tension and the loosening are eliminated by automating the operation to reduce the heightening and the lowering. A method of the automation includes centering the beam from winding width data of the beam and a distance sensor, displaying the position for starting the reed, calculating a reed width L5 from a reed pitch information and a yarn count, calculating the slope of the reeds 12 from the width L5 and the beam winding width L4, and imparting a required slope to the reeds 12 by a servomotor M1. As a result, the beam position corresponds to the winding width L4 when the reed yarn width L5 passes a winding part to eliminate the heightening or lowering of the selvage part in winding.