Patent GB-1411854-A (GB)
Title: Process and apparatus for the manufacture of a soldered multiple  glazing unit
IPC: B23K1/14
Filed: 1973-02-08
Abstract: 1411854 Joining glass to metal; multiple glazing units GLAVERBEL-MECANIVER 8 Feb 1973 [11 Feb 1972 (2)] 6297/73 Heading C1M [Also in Division B3] In making a glazing unit comprising joining metallized margins of a pair of spaced sheets of glass to an intermediate spacer strip or strips the formation of the joint between at least one of the sheets and the or at least one strip includes applying solder into the corner angle between the sheet and strip to form a solder bead joint, the solder being applied as a continuous stream of solder discharged directly into the corner angle from an orifice between which orifice and the sheet relative movement is effected. A glazing unit assembly 2 comprising two sheets of  glass 3, 4 and a spacer strip or strips 5 is supported on a plurality of endless conveyer belts 10, the margins of the sheets being metallized with copper which may be coated with a tin based solder alloy. The strip 5, e.g. of leadbased alloy possibly pre-coated with solder has been soldered to the coated margin of the sheet 3 and the assembly thus formed is inverted and placed on the glass sheet 4. Solder 15 in a container 14 is heated by an electrical resistance device 16 to a molten state and the solder is discharged from a nozzle 21 as a continuous stream 23 into the comer angle of the strip 5 and sheet 4 to form a bead 9. The height of the container 14 is automatically adjusted in dependence on the thickness of the glass sheet and the flow of solder from the nozzle 21 is determined by a needle valve 25 under remote control, the opening and closing of the valve depending on movement of a glazing unit assembly past the soldering installation. Rollers 34 press on the upper glass sheet and gas burners 36 preheat the margin of the glass sheet 4 while gas burners 37 preheat the spacer strip and the metal coating on the glass sheet margin. Downstream of the container 14 further gas burners 38 apply their flames to the solder bead. The strip and glass sheet 3 may be initially joined by a solder bead produced by a soldering iron and the glazing unit may be inverted and passed through the apparatus when a stream of molten solder is discharged to form a layer of solder on the bead already formed. As alternatives to moving the glazing unit relatively to the solder nozzle, the nozzle may be moved with the unit stationary or both unit and nozzle may be moved. In a modified apparatus the solder stream is directed upwardly into the corner angle between the upper glass sheet and the spacer strip and this modified apparatus and the previously described apparatus may be used together to form the upper and lower beads simultaneously. In a further modified apparatus the stream of solder may be directed into the corner through a tube having its discharge end in the comer. This tube may be flexible having its end in contact with the sheet and strip. When soldering a spacer strip to a single glass sheet prior to assembling the glazing unit a wooden block provides both a rebate for the spacer strip and a metal lathe to overhang the spacer strip. Although a glazing unit having two glass sheets has been described a further glass sheet may be soldered to a further spacer strip or strips to form a triple glazing unit.