Patent GB-369694-A (GB)
Title: Improvements relating to shuttleless looms for weaving
IPC: D03D47/00
Filed: 1931-01-16
Abstract: 369,694. Looms with stationary weft supplies. SHIMWELL, O., Gawsworth Old Hall, Gawsworth, Cheshire. Jan. 16, 1931, No. 1500. [Classes 142 (i) and 142 (ii).] Supplying measured lengths of weft to weft carriers.-In shuttleless looms wherein the weft is drawn out into loop form before being engaged by the weft carrier, each complete loop of weft serves for one weft pick when drawn between the shedded warps, and two successive loops from one side of the warps form a loop in the fabric with the closed end in one selvedge and the free ends in the other, as shown in Fig. 1. Each loop of weft is formed by one or other of hooks o, p, Fig. 2, frictionally mounted on a cord or rope a which passes over pulleys b, c, d, e and is reciprocated from the shaft f by means of a quadrant i and an adjustably mounted connecting-rod h. The weft t from the supply is passed through a guide eye u which is oscillated by cam mechanism (not shown) to present the weft to either of the hooks o or p, as shown in Figs. 11 and 15 respectively, subsequent movement of the cord a causing the weft to be directed between one or other of two clips x, y, the latter having associated therewith a yarn cutter z. At the beginning of one cycle of operations, say when the weft is engaged by the clip y, movement of the guide eye u, to the position shown in Fig. 11, permits the weft to be drawn into loop form by the hook o and one leg thereof to pass through the clip x. When the hook o reaches the end of its movement, the clip x is closed and the clip y is opened, whereupon a depressor 10, Fig. 13, operated from the crank connecting-rod, engages the loop and pushes it into the path of the weft carrier which draws it through a clip 2 and into the warp threads. The returning carrier lays a pick which has been similarly formed at the other side of the loom, but during such movement a second loop is drawn out by the hook p, the guide eye u meanwhile having been moved to the position shown in Fig. 15, thereby permitting the weft to be drawn through the clip y and cutting blades z. The clip x is opened during the formation of the second loop but the weft is held by the clip 2 until the hook reaches the end of its traverse, whereupon the clip y is closed, the weft is severed by the cutting blades z and the newly formed loop is drawn into the shed by the weft carrier. The clips and cutting members are operated from the cam shaft f which turns through one revolution for four picks of the weft carrier. Adjustable stops r, s, Fig. 2, determine the extent of movement of the hooks o, p respectively and the frictional mounting of the latter permit their positions to be corrected at each stroke. Stop-motion, weft.-Two weft detectors 31, 32 mounted beside the warp threads and above the normal path of the weft carrier and the clip 2, are arranged to stop the loom when a thread is absent and a thread is present respectively, the detectors being arranged to operate at different stages in the cycle of operations. Detector 31 is carried by a rod 37, Fig. 7, provided with an arm 38 which engages an oscillating cam 39 and detector 32 is carried by a rod 34 having an arm 35 which engages a cam 36. Both cams are oscillated bv means of a rod 40, from the cam shaft f, and their engagement with arms 35, 38 respectively cause the detectors 32, 31 to be raised and lowered at the required times. The detector 31 is lowered after the laying of the first pick, Fig. 15, and, if the weft is absent the excessive movement of the detector rocks the rod 37 and moves a lever 42 into path of a bunter 44 which tilts a lever 43 and moves a brake lever 33 to stop the loom. Similarly the detector 32 is allowed to fall after the second loop has been laid in the fabric, Fig. 11, and, if weft is present, the lever 45, which is connected to the rod 34 by a link 46, is left in front of bunter 44 which moves the lever 43 and stops the loom.