Heat treating moving glass sheets on modified gas bed

Abstract From the Canadian patent

This invention relates to the tempering of glass sheets and, particularly concerns cooling heat-softened glass sheets sufficiently rapidly to induce a stress pattern through the thickness of the glass of sufficient magnitude to temper the glass sheets with minimum surface deformation in a process where flat glass sheets are conveyed while supported on a modified gaseous bed that comprises an upstream portion having opposed modules with thin slotted openings that provide thin discrete, laminar streams of tempering medium against the opposite major surfaces of said glass sheets and a downstream portion having opposed modules that provide a smoother support bed than said discrete streams …