Glass sheet heating furnace and method of using

Abstract

The invention comprises a tunnel-type heating furnace of modular construction for heating glass sheets carried therethrough in succession on a series of aligned rollers. The furnace enclosure includes a lower section of generally rectangular cross-section beneath the rollers and an upper section, which is of generally elliptical configuration in cross-section, above the rollers. The upper enclosure section is vertically retractable by means of a jack mechanism to facilitate maintenance and changing of the rollers. The rollers include shafts at their opposite ends having bearings adapted to be received and supported in upwardly opening recesses in roll support plates extending along either side of the furnace. A toothed gear or sprocket is affixed to the end shaft at one end of each roller. The rollers are driven in groups by timing belts whose upper flights extend over and engage the toothed gears. Hold down assemblies removably carried by the roll support plates include cam rollers positioned intermediate each pair of toothed gears for urging the timing belts downwardly into driving engagement with the toothed gears. A differential heating assembly may be provided for modifying the heating pattern beneath the elliptical upper enclosure section.