| 摘要 |
<p><PICT:1017753/C1/1> <PICT:1017753/C1/2> An apparatus for use in the manufacture of flat glass during which a ribbon of glass is advanced along a bath of molten metal comprises a tank structure for containing a bath 1 of molten metal (e.g. tin), temperature regulators 9, 10 for maintaining thermal conditions along the bath to ensure that a formed glass ribbon is sufficiently stiff to permit to be taken unharmed from the bath through an outlet 12, a roof structure 6, 7, 8 extending over the tank structure to define a headspace over the bath and also over means 16 for supporting the ribbon 11 and taking it up off the bath and discharging it through the outlet, and means for maintaining a plenum of protective atmosphere in the headspace. The ribbon supporting roll 16 is placed in a pit 14 which is an extension of the bath 1. A plenum of protective atmosphere is maintained in the pit to prevent ingress of external atmosphere. Alternatively a conveying roll 18 may be placed in a second pit 17 therebeing also provided a sealing means such as a carbon brush 21 spring supported in a seat 22 attached to the floor of the pit, the brush 21 being in sealing relation with the roll 18. A plenum of protective gas is also maintained in this pit. In this latter embodiment a wall 26 having a groove 28 and pipe 29 for the delivery of protective gas under pressure towards the outlet as described in Specification 1,017,752 may be placed directly above the wall 19 between the two pits. The roll 16 may be of porous carbon so that protective gas under pressure may be passed through it, or may be steel with a covering of carbon rings. The roll 18 is preferably of stainless steel.</p> |
