Patent GB-774378-A (GB)
Title: Process and device for weaving
IPC: D03D47/26
Filed: 1953-06-25
Abstract: 774,378. Looms. TRIKOTFABRIKEN J. SCHIESSER AKT.-GES. June 25, 1953 [July 22, 1952], No. 17628/53. Class 142 (2). Shedding and beat-up are effected progressively across the loom in the form of travelling waves embracing a close succession of weft carriers each containing sufficient yarn for one pick. The warp threads are shed by a weak force acting continuously in one direction and a strong force acting intermittently in the opposite direction, and are selectively locked against movement by the weak force to produce patterns. SHEDDING MECHANISM. In the loom shown in Fig. 1, a continuous stream of air from a slot 8 blows the warp threads 3 upwards, and resilient arms 9 actuated by cams 11 press them down, locking devices 19 (described below) being provided to hold them down as required. In other constructions, the downward component of the tension in the warp threads constitutes the weak continuous force, the intermittent strong force, acting upwardly in these cases, being provided either by compressed air flowing through the locking devices 19, or by a backrest roller having a helical surface, the ridges of which lift different warp threads as the roller rotates. WARP LOCKING DEVICES. In the construction shown in Fig. 12, an electromagnet 37 has an armature 36 which can hook into a heald strip 32 when the warp thread passing through the eye 31 is in its lowermost position. As shown in Fig. 10, the warp thread passes through an eye 25 in a rod 26 which can normally pass between kinks 24 in a loop 23, but is prevented from rising by energization of a magnet 22 which draws the kinks together ; in this form, the continuously-acting force can be compressed air in a chamber 13 urging the rods 26 upwards until their enlarged ends 30 abut a stop plate 29. The rods 26 and air chamber 13 may be omitted, the kinks 24 then acting directly on the warp thread. WEFT INSERTING SPOOLS. In the construction shown in Fig. 1, spools 45, previously wound with sufficient weft for one pick, are propelled by multipole magnets 46 mounted in an endless chain 47 ; the spindles 50 of the magnets roll on a track 51 to rotate the spools 45 at such a speed that the weft is laid without tension. SHUTTLES. The spools 45 may be carried by shallow shuttles 61, Fig. 6, propelled by helically-disposed fingers 63 acting on their trailing edges. The leading edges 60 of the shuttles are wedge-shaped to spread the warp threads apart, the separation effected by the shedding mechanism being less than the thickness of the shuttles in this embodiment. Instead of being wound on a spool, the weft may be contained in a tube situated along the leading edge of the shuttle. HOLDING WEFT ENDS. As a spool 45 enters the shed, Fig. 17, the free end of its weft is blown under a springy clamping jaw 68 on a rotating disc 67, the jaw being depressed by a fix cam tract 68<SP>11</SP> to grip the weft until the shed has closed on it. BEAT-UP MECHANISMS. Springy arms 71, Fig. 1, carrying beat-up blades 72 are rocked by helically-disposed cams 73 ; the blades may ride on a fixed cam track 77. The blades may be operated as in Fig. 6, where the blades 71<SP>11</SP> move farther forward than the blades 71, and compressed air at 70 blows the weft against the blades to produce slack before it is finally beaten up. In another form, the springy arms are attached to and coiled halfway round a rotating shaft, the beatup blades being depressed by a fixed cam track to clear the fabric immediately they have pushed the weft up to the fell. In another construction, Fig. 18, a rotating shaft 79 carries electromagnets 80, the armatures of which are constituted by pivoted beat-up blades 81 ; the resistance to further movement of the weft thread when it reaches the fell causes the blades to swing away from the magnets, the beat-up pressure being therefore dependent on the energizing current; the blades are blown into contact with the magnets again by an air jet 82. SELVEDGES. The ends of the weft threads may be secured by including thermoplastic warp threads at the edges and passing them between heated nip rollers 89, Fig. 1.