PURPOSE: To always regulate the warp yarn tenseness in a prescribed state, improve the quality of a woven fabric and save energy by automatically regulating the rotating and braking of a warp yarn winding drum through a rotation braking part with the roller displacement of a warp yarn tenseness sensor.

CONSTITUTION: Rushes alternately fed from right and left rush dividers into a row of warp yarns 14 delivered in a tensed state are woven into the row in a rush weaving part 16 with a warp yarn winding drum of a rush loom. In the process, when the diameter of a winding drum 12 is gradually reduced with the advance of the weaving and the length of delivered warp yarns is reduced to raise the tenseness of warp yarns 14, a roller 64 of a tenseness sensor 24 arranged on the front surface side of the warp yarns 14 is pushed up to turn ON a proximity switch 58 and drive a motor 48 of a brake regulating mechanism 22. A screw metal 40 is transferred in the direction of an arrow by the driving with the motor 48 to loosen the urging force of a spring 34 in a rotation braking part 20. Thereby, the braking force for a braking wheel 28 is reduced to increase the rotational frequency of the winding drum 12 and automatically return the tenseness of the warp yarns 14 to the original state.