Abstract: The device for repairing a yarn break includes a folder blade which is to be inserted between the warp yarns adjacent a broken yarn. During horizontal motion, the folder blade has two wings which diverge outwardly for spreading out the warp yarn. The folder blade also has a longitudinal groove to receive a heddle in the narrowest place between the wings. A sensor on one wing first determines the position of the heddle in the warp direction and generates a signal so that the folder blade comes to a stop with the heddle in the groove of the blade. A separate warp yarn can then be threaded into the heddle by drawing-in tubes.