Method of driving a glass tempering system and a glass tempering system

Abstract

The present invention relates to a method of driving a glass tempering system and to a glass tempering system for carrying out the method. The main components of the system are a loading section, a heating furnace, a quench and cooling section and an unloading section. The sections are provided with conveyors, which are made of horizontal rollers and can be driven in unison or separately. The furnace and quench and cooling section conveyors are provided with a common drive mechanism for driving the conveyors either at the same rate of speed or for permitting stoppage of the quench and cooling section conveyor. Instead of stopping the quench and cooling section conveyor, it can be coupled to the common drive mechanism through a reduction gear to effect a very slow movement after the quenching is finished and a glass sheet load is being cooled to a handling temperature. By stopping the glass or setting the glass in the quenching and cooling section in very slow motion after quenching, stresses are produced in the already quenched glass which do not normally damage the quenched glass but which shatter those glasses that would later break due to pre-existing faults. Moreover, the stationary or very slowly moving conveyor minimizes damage to the quench and cooling section rollers when glasses shatter. During the quenching, the furnace oscillates empty without a sheet glass load so that the furnace will have time to compensate for a furnace overload caused by even the thickest glass sheets prior to passage of fresh glass sheet load into the furnace.