Patent GB-483626-A (GB)
Title: Improvements in or relating to thread cutters for automatic weft-replenishing looms
IPC: D03D49/70
Filed: 1937-08-12
Abstract: 483,626. Cutting &c. weft. SCHWABE, K. Aug. 12, 1937, No. 22145. Convention date, Aug. 12, 1936. [Class 142 (iii)] In an automatic weft-replenishing loom with a three cell drop box A, B, C, Fig. 8, the cutting operation is controlled by a shaft 73 rotating at the same speed as the crank-shaft and by the change shaft 69 rotating during the weftreplenishment, the actual release of the cutter being determined through the medium of stepped latch devices carried by the drop box at the replenishing side. The cutter may comprise three parts or groups of parts for example a blade 8, a counter blade 11 and clamping fingers 13, 15 rotatably mounted on a shaft 4 on the lay. The parts 8, 13 rotate with the shaft, which is driven by means of a rack bar 28, whilst the parts 11, 15, which are loose on the shaft, are driven by rack bars 27, 26. These are guided on the lay and are moved at the beat up to the position shown against the action of springs, by a fixed part 76. They are afterwards retained by locking levers, 32, 33, 34. When the change shaft 69 rotates, a cam 71 closes a switch 72, an electromagnet 47 is energized and its armature 46 rocks the spring controlled locking lever 32, which is freed from noses 40, 41 on the rack-bars 24, 28. The former is at this time retained bv the locking lever 34, but the latter swings out, and the parts, 13, 8 move to the position shown in Fig. 5, the blade 8 moving the wefts extending from the inactive shuttle box compartments to the position shown. The switch 72 is temporarily reopened and the locking lever 32 returns, and owing to the movement of the lay, the locking lever 34 is operated to release the rack-bar 26, the switch is again closed, and the bar 26 causes the counter finger 15 to move clockwise to grip the thread from the spent shuttle in its notch 18 and clamp it against the clamp finger 13, a three-edged rib 16 entering a groove 17. Whilst the bar 26 is moving forwards, it releases the locking lever 33, and the bar 27 operates the cutter blade 11, which cuts the threads. The cam 70 then turns a lever 62 from a position 1 to 11, thereby closing a switch 65. The vertical wall 53 of the multi-cell shuttle box carries step pawls 54a, 54b, 54c connected by springs to locking-pawls 56a, 56b, 56c, and guides 631, 63<11> on the lever 62 engage a pin in one of the pawls 54c turning the pawl anticlockwise so that the locking-pawl 56c moves from a lower to an upper notch in the step pawl retaining this in the position shown. If the replenished shuttle comes into action at once, the step pawl retains the lever 62 in the position 11 with the switch 65 closed and when a further switch 75 is closed by a cam on the shaft 73, the electromagnet 47 is again energized, and the rack-bars are freed, whereby the cutter is again operated to cut the weft from the fresh shuttle. If, however, the boxes A, B, C move and the replenished shuttle does not come into action, the pin of the step pawl 56c moves away from the lever 62 which returns to position 1, and the operation of the weft cutter is delayed until the shuttle again comes into action, and the corresponding step pawl 56c operates the lever 62. A tooth 49 on the bar 27 engages a lever 50 and turns a shaft 51 and lever 68 to disengage the locking-pawl 56c from its step pawl.