Patent GB-129531-A (GB)
Title: Improvements in Devices for Effecting Loom Stoppage in the Event of Misthreading or Failure of Filling after Filling Replenishment.
IPC: D03D51/00
Filed: 1918-10-04
Abstract: 129,531. British Northrop Loom Co., (Northrop Loom Co.). Oct. 4, 1918. Stop-motions acting on too frequent weft-replenishment. Two separate members are connected to and movable with the weft-fork slide and are independently positioned to effect loom-stoppage on the occurrence of two hopper misthreads and one real misthread respectively. As shown, the front end of the weft-fork slide 11 is connected to an arm 10 on the shaft for initiating weft-replenishing, and a latch-carrier 25 is guided on the slide 11 by a bridge-piece 31, which normally contacts with a projection 32 on the carrier to position this with a projection 24 thereon in a front shallow notch 21 in the slide, so that a latch 26 on the carrier is held up above the end of the shipper lever 27. When the weft fails, the hook 17 of the weft hammer 15 engages the tail 14 of the weft fork 13 and moves the slide 11 forwards to rock the arm 10 and initiate weft-replenishment, and the movement of the carrier 25 is arrested by a downward projection thereon meeting a fixed stop so that the projection 24 moves into a second shallow notch 22 in the slide 11. If a hopper misthread occurs, the slide 11 is moved forwards again at the next forward stroke of the weft hammer and a second downward projection on the carrier 25 meets the fixed stop, so that the projection 24 moves into a third deep notch 23 in the slide and the latch 26 drops into position to strike the shipper lever 27 and stop the loom if the slide 11 is moved forwards on the occurrence of a second hopper misthread. If a hopper misthread does not occur; the weft hammer 15 in its forward movement strikes the rear end of the carrier 25 and restores it to its initial position with the projection 24 in the notch 21. To stop the loom on the occurrence of one real misthread which would be detected on the second detecting beat after replenishment, a second slide 44 is mounted in a groove 46 in the weft-fork stand 19, and a slot 43 in its front end engages a pin 42 on a lever 37 pivoted at 36 to the arm 10 and having a fork 38 on its lower end engaging a fixed pin 39. The slide 44 has a recess 48 between front and rear shoulders 47, 49 for co-operating with a stud 52 on a hooked arm 50 pivotally carried by the upper end of the arm 10. Normally, the stud 52 rests on the front shoulder 47 and holds the hook of the arm 50 above the end of the shipper lever 27, and on forward movement of the slide 11 the stud 52 moves to the rear shoulder 49, the slide 44 moving farther forwards than the slide 11. The slide 44 has three teeth 53, 54, 55 at its rear end and a pawl 56, pivoted to an arm 58 on the weft hammer, normally engages the front tooth 55. When the weft hammer moves forwards, the pawl 56 rides up the inclined rear edge of an adjustable piece 60, and on the return of the weft hammer the pawl engages the rear tooth 53. If there is no hopper misthread, the carrier 25 is restored to its normal position as described above, and, when the weft hammer returns, the pawl 56 engages the second tooth 54 and moves the slide 44 into such a position that the stud 52 drops into the recess 48, so that the hook of the arm 50 engages the shipper lever 27 at the next detecting beat if a real misthread occurs and prevents tilting of the weft fork. The slide 44 is returned to its normal position by cooperation of the pawl 56 and the teeth 54, 55.