Patent GB-547748-A (GB)
Title: Photo-electric protecting device for looms
IPC: D03D51/28
Filed: 1941-03-28
Abstract: 547,748. Loom stop motions. GUTMAN, A. S. March 28, 1941. No. 4208. Convention date, March 30, 1940. [Class 142 (i)] [Also in Groups XL and XXIV] A loom is provided with a photo-electric device arranged to project a beam of.light through the open shed near one or both corners and to cause the loom to stop if the beam is interrupted by a broken warp yarn or by the formation of a float. In the form shown in Figs. 1 and 5, the photo-electric device comprises a lamp 432, mirrors 440, 442, 444, 446, a photo-electric cell 434, a usual circuit therefor (not shown) and an electromagnet 436. The loom is driven from a belt pulley 344 through a clutch 348, shaft 336, gearing 360, 362, 366 and a shaft 368, the rest of the driving gear being conventional and not shown. An eccentric 370 on the shaft 368 serves to reciprocate a hook member 376 alongside another hook member 384 connected by linkwork to a pivot 394 on a vertical rod which is pivoted at its lower end to a foot lever 424 pivoted at 426 and connected at its inner end to a brake 358. The rod 392 is fitted with a cam 408 bearing against a lever 410 pivoted at 412 and connected at one end to a starting handle 414 and at its other end to one end of a rod 420, which is connected at its other end to the clutch lever 350. During normal operation the parts are in the position shown, the rod 392 is held down against a spring 402 by the engagement of its shouldered upper end 406 with the edge of a slot in the face plate 400, and the hook member 384 is held up by the electromagnet 436. If the beam of light is interrupted as mentioned above, while the shed is open, the electromagnet 436 releases the hook member 384, this hook is engaged by the hook member 376 and driven to the right by the eccentric 370 and the rod 392 is thereby deflected and released at its shouldered end 406, whereupon the spring 402 moves the rod 392 upwards thereby swinging the foot lever 424 to apply the brake 358 and at the same time swinging the lever 410 to open the clutch 348. The interruption of the light beam by the normal closing of the shed is rendered inoperative on the stopping mechanism by any suitable timing device, provided for in the form shown by the hook members 384,376. When the shed closes the hook member 376 is to the right or below the hook member 384; and on the completion of the stroke of th e hook member 376 to the left, which occurs after the opening of the shed, the hook member 376 acts on the root 382 of the hook member 384 and lifts it against the electromagnet 436 to ensure its being held up thereby. Thus the stopping operation can only take place if the light beam is interrupted white the shed is open during the stroke of the hook member 376 to the right. The clutch is held in its open and closed position by a spring 422 surrounding the rod 420 and extending between fixed abutments 421, 423, so as to tend to increase the deflection of the rod 420 about its central position. The Specification as open to inspection under Sect. 91 describes also photo-electric devices operating when the weft in a shuttle is exhausted for stopping the loom or controlling weft replenishing devices. This subject-matter does not appear in the Specification as accepted.