Innovative press bending of thermoplastic sheets

摘要

A press bending apparatus includes a shaping station having an upper mold with a shaping surface having a generally concave downward elevational configuration and a lower mold with an apertured shaping surface complementing the shaping surface of the upper mold. A vacuum shuttle transfers heat softened glass sheets from a heating furnace to the shaping station where it deposits the glass sheets on the lower vacuum mold. The glass sheet is shaped between the molds. A rotating arrangement rotates the lower mold and the shaped glass sheet held thereagainst by vacuum from a first position wherein the shaping surface of the lower mold faces upward to a second position wherein the shaping surface of the lower mold faces downward. The shaped glass sheet is then deposited on a tempering ring. A rotating arrangement maintains vacuum in the lower mold as the mold rotates.