Patent GB-748616-A (GB)
Title: Improvements relating to looms for weaving
IPC: D03D47/00
Filed: 1953-08-14
Abstract: 748,616. Shuttieless looms. WEAVING RESEARCH & TEXTILE COMMISSION AGENTS, Ltd., and SHIMWELL, D. W. July 30, 1954 [Aug. 14, 1953; Aug. 14, 1953], Nos. 22441/53 and 22442/53. Class 142 (2). In a loom wherein two weft yarns are carried into the warp shed from opposite sides thereof by reciprocated spears a, b which follow each other closely across the shed, the warp threads are shedded progressively across the loom in the space between the spears so that the two weft  yarns are laid in different sheds, and means are provided at each selvedge for cutting the loops of weft so laid. Means are provided for pressing each spear into the fell of the cloth when the spear extends across the cloth to effect beatup. A selvedge pin is provided at each selvedge and is inserted into the double weft pick so that the weft is looped round it; the selvedge pin includes the cutter, which when the pin is lowered into a loop severs the loop. Means may be provided to take up slack in the weft when a spear is moving out of the shed. Shedding.-The head staves are divided longitudinally into sections 15 ... 18 pivoted together, separate cams 20 being provided for raising and lowering the pivots 19 connecting adjacent sections. Weft-inserting.-Two spears a, b are provided, each having a gap c dividing it into upper and lower parts, each of which parts is provided with a weft guiding tube d so that two weft yarns e are laid simultaneously, so that in the simultaneous weaving of two fabrics, one weft yarn is laid in each of two sheds, the gap c positioning the upper warps of the lower shed and the lower warps of the upper shed. Each of the two spears is operated by a chain q attached at an intermediate point to its spear and anchored at its ends u, v; each chain passes around wheels x on a carriage y, the two carriages being reciprocated from a common crank 2 by connecting rods 4, 5 so that the spear moving from the beat-up position moves faster than the spear moving into the shed to widen the distance between the spears so that progressive shedding is facilitated. Forming selvedges.-A selvedge pin 30 having a cutting blade 118 is located at each selvedge and is lowered, when the spear carrying weft yarn from the yarn supply on the opposite side of the shed reaches the end of its stroke, behind the enlarged head f of the spear to engage the weft thread, is then moved with the weft thread thereon to clear the head f as the spear reverses its movement, is moved close to the selvedge and raised to release the loop and is finally moved away from the selvedge for a next cycle of operation. The pin 30 is mounted on a slide 33 carried in a guideway in a member 34 having a forked end straddling the flattened part of a spindle 36. The member 34 has a cam follower 40 engaging a bottom cam 44 to move the member 34 angularly about the spindle 36 and engaging side cams (not shown) to move it at right angles to that angular movement. The slide and pin 30 are raised by a cam 50 engaging a follower 49 on an arm 48 supporting a roller 51 on the slide, and are returned by springs 52. When loops around the pin 30 are to be cut, a lever 120 is moved from under a projection 119 on the slide 33 to allow the pin to be drawn further downwards sharply by the springs 52 so that the blade 118 cuts the loops. The selvedges may be as shown in Fig. 14, lengths of weft 114, 115 corresponding to a double pick being cut; the cut end at one end of each length is folded over before it is inserted into the shed. Alternatively singlepick lengths are inserted, the initial end of each such length being folded over to embrace the end of the previous pick.