Abstract: An apparatus for detecting a break in a warp yarn in a loom includes a heald, a heald frame, a carrier rod, a sensor, a controller and a signal line. The heald is made of a resin material for guiding a warp yarn. The heald frame performs a shedding operation of warp yarns and has the carrier rod for supporting a plurality of the healds. The sensor is provided in the heald for sensing a deformation of the heald caused by a tension of the warp yarn and outputting a signal. The controller is provided for determining a condition of the break in the warp yarn based on the signal of the sensor. The signal line electrically connects to the sensor and the controller.

Abstract: Drop pin for stop motion (1) comprising a body (2) with a yarn lead-through opening (3) provided to rest on a thread extending through this opening (3). The drop pin is supported by a supporting surface or edge (4), forming a concavely curved bordering of this opening (3) and which, in cross-section, has a convex form. The supporting surface (4) may have a rounded spherical form or a form with a number of angle forming sides, such as for instance a polygon. Preferably, the yarn lead-through opening (3) is circular. Also provided is a device for detecting the thread breakage on a weaving machine, comprising a number of similar drop pins for stop motion and a weaving machine provided with a similar device.

Abstract: A vertically reciprocatible heddle frame has side beams including a heddle bar fixed to the side beams, and heddles loosely mounted on the heddle bar with vertical play. A device for detecting end breakage of yarn supported by the heddles consists of an electrically conductive bar mounted on a resilient holding element. The resilient holding element leaves access at the top for contact between the heddles and the detecting bar. An electrical current flows through the detecting bar only during the downward movement of the heddle frame. End breakage of yarn permits a heddle to contact the detecting bar during such downward motion, and the resulting completed electrical circuit can be detected by appropriate detecting means.

Abstract: 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.