Device for detecting the loss of tension of a warp yarn in a weaving loom

摘要

At least one elongate electrode is positioned on the upper surface of an upper heddle bar of each heddle frame of a loom for constituting a switch with loops loosely coupled to the upper heddle bar, each loop being spaced from the upper surface of the upper heddle bar at the lower position of the heddle bar due to upward force along the heddle produced by the tension of a warp, the switch being closed when a loop hangs over the electrode by its self weight due to loss of tension along the warp at the lower position of the heddle bar, the lower position of each heddle bar being detected by a heddle bar position detector, a corresponding LED being illuminated by a display circuitry connected to the switch and the heddle bar position detector, the circuitry including holding circuits for maintaining the illumination of the LED from the first glowing until the holding circuit is reset.