METHOD FOR THREE STAGE FORMING A HOT GLASS SHEET WITH TRANSVERSE CURVATURE

摘要

A glass sheet forming method utilizes first and second upper molds and a lower mold to provide three stage forming. The glass is curved on the upper mold in the first stage but retains straight line elements transverse to the curvature. Transfer of the initially formed glass sheet from the first upper mold to the lower mold then provides the second stage of gravity forming and the glass sheet is then press formed between the second upper mold and the lower mold in the third stage which reduces optical distortion in the central viewing area of the formed glass sheet. In one embodiment the glass sheet is moved horizontally on the lower mold, and in another embodiment the glass sheet is moved horizontally on the first upper mold.