Patent GB-289570-A (GB)
Title: Improvements in or relating to looms for weaving having stationary weft supplies
IPC: D03D47/00
Filed: 1927-02-04
Abstract: 289,570. Gledhill, W. Feb. 4, 1927. Shuttleless looms.-The weft is drawn from a stationary supply comprising one or more bobbins 13 and is taken to the left half way across the shed by a delivering gripper shown in plan and elevation in Figs. 1 and 2 respectively. The weft is then delivered to a receiving gripper 10, 11, both grippers then reciprocating outwards from the centre of the shed so that the weft is taken to the left to the other side of the shed by the receiving gripper whose jaws are movable in a plane at right angles to those of the other gripper. The weft is drawn through the delivery gripper as this returns to the right. The weft is then released from the receiving gripper and beaten up, the end extending from the supply through the gripper to the selvage being cut and the cut end whipped back through the warps of the upper shed as shown in Figs. 10 and 11. Means are described for inserting any one of a number of different wefts and for tensioning these weft grippers. The warp threads and carrier bars for the grippers may be arranged vertically instead of hoizontally and two carrier bars may be used to lay wefts in two sheds simultaneously. Construction and arrangement of grippers: transferring the weft from one, gripper to the other at the centre of the shed. The delivery grippers comprises jaws 1, 2 pivoted together at 3 and serrated to grip the weft. A spring 7 holds the jaws either open or closed by acting on either of two surfaces 6<1>, 6<2>. The jaws are shaped to form a recess 4 and the weft passes from the stationary supply through a slot 5 to the gripping parts 1<1>, 2' of the jaws. At the centre of the shed, the tapered nose 1<5> of the delivering gripper engages wedge-shaped parts 10<2>, 11<2> of the thread gripping jaws 10, 11 on the receiving gripper, thus opening, these jaws against the action of a spring 15. Finally the nose i<5> passes into a recess 14 between the jaws 10, 11, which then close and grip the thread. When the grippers commence their return journey from the centre of the shed, the parts 10<4>, 11<4> of the closed jaws 10, 11 act on the tapered parts of the jaws 1, 2 adjacent the recess 4, thus opening these jaws and releasing the weft W, which passes freely through the slot 5. The receiving grippers are provided with a curved wire .16 and their carrier bar 13 is provided with a spear head 13<1> to prevent the jaws from fouling the warp threads. The jaw 1 of the delivering gripper may be provided with a threading slot for the weft. The shank i<3> of the jaw 1 is slotted vertically at i<4> to receive a projection 8<1> on a horizontally reciprocated carrier bar 8, a spring-member 9 on which engages a recessed part of the jaw, so that by a vertical movement the delivering gripper can be attached to or detached from the bar 8. Gripper reciprocating mechanism. Each gripper carrier bar is horizontally guided by a guide 17, Fig. 5, on the lay and is connected to a picking-stick 18 furnished at its lower end with a roller 19 engaging a vertical slot 20<1> in a bracket 20 on a rocker 21 pivoted to the loom frame. The stick 18 is actuated by an arm 27 fast to a partly toothed pinion 25 actuated by a toothed quadrant 24, which is rocked by a connector 29 actuated by a crank. A plain surface 24<1> on the quadrant gives the necessary dwell of the carrier bar to allow for the change of shed. The stick 18 moves downwardly with the roller 19 when it swings, so that the pivot pin 18' connecting it to the bar 8 moves in a true horizontal path. Checking the gripper reciprocating mechanism. The outward movement of the stick is checked by a strap 34 and the inward movement by the engagement of the pin 18<1> with a leather strip on the curved end portion of a bar connected to a weighted disc. Gripper opening and closing devices. The delivering gripper makes its outward movement open and it is closed to grip the weft ready for its next inward movement by the engaging end 35<1>, Fig. 7, of a lever 35 pivoted on the lay pressing against the open jaw 2. The lever 35 is operated by a spring contact on a bar on the breast beam. The receiving gripper is opened at the end of its outward movement by the entry between the shanks of the jaws 10, 11 of a bent portion of a member pivoted to the lay and actuated by a rod furnished with a collar and working through a block pivoted on the breast beam. Weft supplying and tensioning. The weft is supplied from one or more bobbins B, Fig. 20, on spindles 71 on a frame 70 hooked over the breast beam, and the weft ends pass through guide-eyes 75 and through openings 72<1> in the cross bar of an inverted U-shaped member pivoted to lugs on the breast beam and rocked by a connection 74 to the lay, whereby the slack which occurs during the beat up of the lay after the receiving gripper has ceased to draw off and the delivering gripper has closed again upon the weft is taken up. Multiple weft arrangement. In order that any one, of several wefts may be inserted into the shed, a number of delivering grippings 7, Fig. 14, each threaded with a weft are housed in superimposed cells 66<1> in a carrier box 66 connected by a link 69 to a dobby, pattern chain &c. so that the box is vertically reciprocated to present opposite the weft delivery line the cell or chamber corresponding to the weft of the colour &c. desired. A fixed bar 67 has a notch 67<1> to admit a delivery gripper and each delivery gripper has a notch to fit the bar 67 whereby such grippers are held during their periods of non-activity, whilst the gripper in active position is held by the spring over the projection on the carrier bar 8 and is thus reciprocated therewith. Vertical movements of the grippers detach or attach them to the bar 8 as already described. Weft cutting and selvage forming devices. The weft extending to the delivery gripper is cut when the gripper moves forwards by a rotating cutter disc 43 actuated by the movement of the lay by means described. The weft ends projecting at each side of the loom are cut by sickles 56<1> on wires 56 on spindles 52 mounted in cylindrically-bored blocks 50'. A set screw in each block engages a spiral groove 52<1> in each spindle, which is moved backwards and forwards as the lay moves to and fro by a spring blade 54 actuated by a member 55 on a lay abutment 49. The wires 56 are thus moved bodily forwards and rotated, cutting the wefts, whilst hooks 56<2> on the wires whip the cut ends into the upper warp threads of the shed. A strong thread 57 may be raised and lowered outside the warps for the sickle to loop round. In a modification, vertically-moving needles at each side of the fabric draw supply of binding-yarn from respective cheeses and are raised at each pick or after several picks. They may be stepped inwards'gradually to form a zig-zag selvage or binding. Means for giving lateral movements to the needle are described. The weft ends may be tied in by means of two threads extending from bobbins in a rotating frame, so as to be wrapped around the thread 57 and also around one or more of the edge warp threads. The Provisional Specification describes a modification in which eves or mails on an endless band secured to intermittently rotated pulleys carry binding yarns, which are caused to cross the last inserted weft or wefts.