Patent GB-1430246-A (GB)
Title: Apparatus for fabricating welded wire structures
IPC: E04C5/06
Filed: 1973-03-21
Abstract: 1430246 Welding by pressure V P WEISMANN 21 March 1973 [22 March 1972] 13479/73 Heading B3R  Welding apparatus for making a threedimensional rectilinear matrix comprising longitudinally and transversely extending wires on each of the two opposite sides and wires transversing the interior of the matrix, each generally in the plane of, and interconnecting a pair of the longitudinally extending wires disposed one on each side of the matrix, comprises coaxially aligned first and second electrodes, for welding to each of two longitudinally extending wires of the matrix interconnected by interconnecting wires, one of said transversely extending wires, means for moving the first and second electrodes towards and away from each other and an electrically conductive anvil for movement along a path normal to the first and second electrodes between a welding position between the electrodes and a retracted position spaced from the electrodes. A building panel 10, Fig. 1, comprises an insulating core 12 disposed within a matrix 11 formed of parallel truss sections 9, each formed of an upper wire 13, a lower wire 14 parallel thereto and connecting end wires 18 and strut wires 17, connected together by parallel spaced upper and lower wires 15, 16 at right angles to the wires 13 and 14. The truss sections are made by supplying two wires 31, Fig. 3, from coils 30 (only one being seen) through a straightening station 32 and on to the upper portion of a conveyer belt 33 where they are carried past a station 37 for dispensing end members 18, stations 38 and 39 for dispensing struts 17, a station 42 for resistance welding the members 18 to the wires 31 and stations 45, 48 for resistance welding the struts 17 to the wires 31. The finished truss section is wound on a reel 111. The belt 33 is of the bicycle chain type and between the two end axle pins 53, Fig. 4, a belt length adjustment means is provided comprising a screw shaft 63 having threads 62 of opposite hands engaged respectively in threaded holes in blocks 60 through which the pins 53 pass. A pinion gear 64 is provided on the shaft 63 and this gear is in engagement with a worm 65 mounted in a block 66 which journals the shaft 63, the worm being connected to an operating wheel 70 having spur teeth. In a station 40 solenoids are arranged so that on operation of one of them the corresponding armature is moved out to engage the spur teeth of the wheel 70, either above or below the axis of rotation of the wheel to effect either a shortening or a lengthening of the chain. A scanning station 51 detects if the trusses produced are too long or too short when a signal is sent to operate the appropriate solenoid. Carrier blocks are mounted on the belt 33, intermediate blocks and end blocks, the former being of electrically non-conductive material and having parallel grooves to receive the wires 31 and a transverse groove across the block to receive the struts 17, with an electrically conductive bar embedded below the transverse groove, and the latter blocks being similar but also having a transverse groove for an end member 18. At the stations 43, 46 and 49 pairs of electrodes are moved downwardly to spot weld the wires 17, 18 to the wires 31 and during welding the welding assemblies move with the blocks. A number of coils 111 of truss sections are arranged at a twisting and feeding station 112, Fig. 15, where each truss section is turned through 90 degrees and fed through a welding electrode assembly 114 where electrodes 120 weld wires 15, 16 cut from coils 141, 142 and fed across the number of truss sections. A mechanism 144 having a reciprocating chain advances the matrix which is cut by parallel abrasive cutting discs 151 driven across the width of the matrix on a track 154 in turn driven on tracks 155 parallel to the direction of movement of the matrix. Each electrode assembly 120 comprises upper and lower electrodes 121, 122, Figs. 16, 19, coaxially aligned and movable towards one another by, e.g. pneumatic apparatus and an intermediate anvil 125. The anvils 125 are each carried on a block 126 which blocks are coupled together by a bar 130 which is reciprocable transversely of the matrix feed direction by a device 131, Fig. 15. Thus each anvil 125 may be moved from a position in which its welding surfaces 139, 140 are out of alignment with the electrodes 121, 122 (as shown in Fig. 19) to allow the truss sections to be fed from the reels 111, to a position in which they are aligned with the electrodes 121, 122 to allow welding of the wires 15, 16 to the truss wires 13, 14. The matrix may finally be provided with its core by foaming polyurethane foam within the matrix or by bonding strips of polystyrene foam within the matrix to the strut members.