Abstract: The weft yarn leaving a drum of a weft yarn store of a loom is monitored by a monitor device having at least two pairs of transmitters and receivers in a monitor ring which output signals to an evaluating unit (W) independently of one another in accordance with the number of yarn windings drawn off the drum. The dual delivery of signals is evaluated in an evaluation unit so that interfering signals can be distinguished from genuine malfunctionings, such as yarn breakages, so that unnecessary interruptions in operation can be avoided.

Abstract: A jet weaving machine is provided with an inserting nozzle at one end of the shed, a guide channel (7) comprised of lamellae (3) (e.g., the reed dents) arranged over the width of the warp shed, for guiding the weft thread during insertion in the shed, a first weft thread monitor (8) disposed in the region of the far end of the shed for emitting a signal when the inserted weft thread has not reached its intended length, and a tensioning device (9) located beyond the first weft thread monitor (8) in the direction of weft insertion (A), for stretching, straightening, and holding (taut) the inserted weft thread until beating-up is performed. The tensioning device (9) is in the form of an element through which an auxiliary fluid flows to take the head of the inserted weft thread which projects out of the shed and bend it transversely away from the weft insertion direction (A).