The invention relates to a weft stop motion, or detector, for looms in which the sensor element responds or is sensitive to an electric charging of the weft thread without contact and also to looms in which the weft break stop motion of the present invention is used.
A concept for thread detection is known from German Patent Specification 3,758,403, for example. Various embodiments of electrostatic transformers are disclosed therein. These sensors are mainly used in air-jet looms. The weft thread is electrically charged during its removal from the weft thread supply because of the resultant friction and also during the weft insertion because of friction with the air. The electrostatic detection registers the presence of a textile fiber which is moving past and is electrically charged in this way, and the passage of the tip of an inserted weft thread in particular can also be detected. Weft break stop motions are used in the weft channel of the loom. The known embodiments are relatively large and heavy and are frequently constructed in the form of a confusor drop wire. The high-speed air-jet looms having a correspondingly high beat-up speed of the reed which are commonly used nowadays produce high vibration and acceleration loads on the known weft break stop motions, so that the known embodiments are no longer suitable for use on air-jet looms or the resultant electrical signals are very noisy.