GB657421A - Improvements relating to the binding of weft threads in weaving - Google Patents

Abstract

657,421. Leno shedding mechanism; selvedges; warp stop-motions. SULZER FRERES SOC. ANON. Mar. 5, 1948, No. 6908. Convention date, March 8, 1947. [Classes 142(i) and 142(iv)] Selvedges. At the edges, and intermediately if the fabric is to be cut into strips, pairs of warp threads are twisted together, picks of weft being inserted after successive twists in the same direction before the twist is reversed. The pairs of threads do not all reverse their twist at the same time. Shedding mechanism. The pairs of threads may be supplied by bobbins mounted on rotatable heads, but preferably the twisting heads shown in Fig. 16 are used, in which case the threads 28. 29 are taken from the normal warp beam or from stationary bobbins; each pair of threads passes through eyes in an externallytoothed twisting ring 35 rotated in 180 degree steps. One mechanism for rotating the rings 35 comprises two cam-oscillated toothed sectors, some twisting rings being operated by each sector; the cams are out of phase with each other and may be rotated by Geneva mechanism. Other mechanisms described employ mutilated gears rotated continuously or by Geneva mechanism. In the embodiment shown in Fig. 7, shafts 41, 42, each actuating some of the twisting rings, are driven by gears 44, 45 spaced round the periphery of a cam 77. The gears carry series of followers engaging a discontinuous cam track, Fig. 8, such that, as a follower 85 emerges from a section 80 of the track, the next follower 86 enters a section 81; the sections, which may be separate pieces capable of being reassembled to change the pattern, include sections which keep the gears 44, 45 still while two picks are inserted in the same shed. Warp stop-motion. To obviate undue vertical movement of the detectors 32, Fig. 16, a lifter 106 actuated by an eccentric 104 supports them as the shed changes. The detectors respond to breakage of whichever thread 28, 29 is uppermost.