Patent GB-704785-A (GB)
Title: A process and apparatus for the manufacture of wire netting
IPC: B21F27/10
Filed: 1951-05-31
Abstract: 704,785. Making wire fabrics. BRUNE, H. W. May 31, 1951 [July 22, 1949], No. 13004/51. Class 83 (4) Bending; welding. In a method of making wire netting by welding together longitudinal wires arranged in a closed circuit round a stationary former and transverse wires helically wound about the former, the crossing points are welded by electrodes mounted on a carrier rotating about the former and the transverse wires are fed from spools mounted on a plate rotating synchronously with the carrier. Longitudinal wires 10, Fig. 4, are fed from reels 8 over a fixed annular former 7 supported by means not shown and transverse wires 19 fed from reels 20 mounted on a rotating plate 21 are helically wound over the former 7 by a rotating ring 17 carying a ring of pulleys 18 over which the wire passes. The wires are welded together on the former 7 and the finished tubular netting is severed at one or more points 27, Fig. 5, and drawn through flattening rolls 30 by winding reels 32. The rolls 30 may be set at an angle equal to the helical angle of the transverse wires so that a square network is produced. The welding is performed by a series of electrodes 59, Figs 11, 12, mounted in an insulated support 63 and disposed over the crossing points of the wires on the former 7. The electrodes are normally yieldingly retracted by springs 62 and are depressed into engagement with the work by electrode rollers 64 mounted on a rotating carrier (not shown) and connected in pairs to a transformer secondary winding so that two wire points are welded simultaneously through a bridge connection. The roll pairs are staggered so that the electrodes are energized consecutively and the loading of the transformer is thereby maintained substantially constant. Insulated portions 60 on the head of each electrode prevent the passage of current until the full pressure is imposed on the electrode by the rollers 64. In another example four transverse wires 116, Fig. 20, are simultaneously coiled over longitudinal wires 107 on a former 100 and are welded together by electrodes 125 which engage several crossing points simultaneously and for a sufficiently short time to permit the longitudinal wires to be continuously fed. The transverse wires are fed from four reels 115 on a rotating disc 110 which also carries a number of notched guides 132 projecting between the transverse wires 117 and the former 100 to locate the wires accurately relative to the electrodes 125. The longitudinal wires 107 are fed over rollers 108, 109 mounted on brackets 194 which are adjustable in position relative to the electrodes to accommodate different wire spacings. The guides 132 have rollers 136 which run over the wires 117 and continuously determine the height of the guides above the former 100, adjustment being provided by a screw 137. The former 100 comprises two annular parts 118 held together by bolts 119 and clamping between them flat metal pieces 120 which form the welding bed and which are also adjustable in position to accommodate different wire spacings. The electrodes 125 are arranged in two rows in staggered relation and are yieldingly mounted in brackets 128 on a fixed ring 102 surrounding the former 100. The flat metal pieces 120 carries spherically seated contact plates 122 mounted under each electrode 125 so that an even contact pressure is obtained at all the wire cross-over points during welding. Pairs of electrode rolls 139, 140 yieldingly mounted on the rotating disc 110 engage the electrodes 125 consecutively in pairs and are arranged so that when lifted during passage over the electrodes, contacts 147, 148, Fig. 18, are engaged, closing the primary circuit of a transformer 205 through a solenoid relay 210. and thereby supplying current from the transformer secondary through leads 152 to the roller electrodes. The formed tubular netting is sheared at diametrically opposite points as it leaves the former 100 by shear blades not shown which are actuated by cams carried on the rotating disc 110. In further examples the formers described are square in section and in another of elongated rectangular section. In the latter case transverse wires 48, 49, Fig. 8, are wound over longitudinal wires 42 on a former 43 from reels 46, 47 on supports carried by a chain 44 running on sprockets 45.