Method and apparatus for tempering moving glass sheets

An apparatus for applying streams of cool gaseous tempering medium against opposite surfaces of heated sheets of glass so as to temper the glass, comprising:

• upper and lower elongated quench beds spaced apart and facing one another in a generally parallel relationship, each quench bed extending in a longitudinal direction from an upstream location adjacent an exit of a furnace for heating the glass sheets to a temperature suitable for tempering to a downstream location spaced from said furnace, each quench bed including a plurality of modules each extending transversely across the width of the quench bed and having slots therethrough and communicating with means to provide pressurized gaseous tempering medium to the interior of said modules and said slots, said slots being about 0.25 to 0.8 millimeter in width and occupying no more than about 6 percent of the area of said quench beds and provided in sufficient numbers distributed throughout the area of each quench bed and so oriented as to direct thin, high velocity sheets of gaseous quenching medium over the surfaces of the glass sheets being conveyed longitudinally between said quench beds in sufficient quantities to cool said glass sheets rapidly enough to temper said sheets, said modules being spaced apart to form exhaust passages therebetween which extend across the width of the quench bed, said exhaust passages occupying at least about 20percent of the area of said quench beds so as to exhaust the gaseous quenching medium from the vicinity of the glass sheets with minimal flow resistance.

Apparatus for tempering hot glass sheets by flowing cool streams of gaseous tempering medium against the opposite surfaces thereof comprising an upper elongated quench bed and a lower elongated quench bed in spaced relation to and facing said upper quench bed, each said quench bed including a series of modules, each provided with a flat apertured wall for applying thin streams of gaseous tempering medium against the surface of a succession of glass sheets conveyed longitudinally of said bed past said modules, said modules being spaced apart to provide therebetween longitudinally spaced exhaust passages extending transversely of said bed continuously across the entire width of said conveyed glass sheets, said elongated quench beds extending from an upstream end adjacent an exit of a furnace for heating said glass sheets to an elevated temperature suitable for tempering and a downstream end, and means to provide cool gaseous tempering medium at a rate sufficient to cause said gaseous tempering medium to flow through said slots at a rate sufficient to cool said glass sheets sufficiently rapidly to temper said sheets and to be exhausted through said exhaust passages, wherein said modules comprise a first pair of opposed modules located immediately downstream of said furnace exit and having their associated elongated slots directed diagonally through the thickness of said flat, apertured walls of said first pair of opposed modules in a downstream direction disposed at a relatively large oblique angle to a plane normal to the major surface of glass sheets conveyed along the length of said bed and a second pair of opposed modules located downstream of said first pair of opposed modules and having elongated slots directed diagonally through the thickness of said flat, apertured walls of said second pair of opposed modules in a downstream direction disposed at a lesser oblique angle to said plane than said relatively large angle.