Patent ID: 8468850
Filing Date: 2013-06-25
Classification: C03B

Abstract:
1. A method for bending a glass sheet, comprising: a preliminary forming step which comprises placing a softened glass sheet on a plate preliminary forming supporting mold which supports edge portions of the glass sheet, and pressing the glass sheet against a forming face of the preliminary forming supporting mold to bend the glass sheet in a preliminary bent shape while the glass sheet is placed on the preliminary forming supporting mold; and a main forming step which comprises transferring the glass sheet in the preliminary bent shape onto a main forming supporting mold which supports edge portions of the glass sheet, and pressing the glass sheet against a forming face of a main forming mold to bend the glass in a final bent shape while the edge portions of the glass sheet are placed on the main forming supporting mold, wherein the preliminary forming supporting mold comprises an outer mold and an inner mold provided inside the outer mold, the inner mold has a flatter glass-plate-placing face than a glass-plate-face of the outer mold, the main forming supporting mold comprises a lower mold provided inside the main forming supporting mold, the lower mold has a forming face opposed to the main forming mold, the forming face of the lower mold and the main forming supporting mold have shapes curved in two directions such that the final bent shape of the glass sheet has curvatures at least in the two directions, the preliminary forming step includes transferring the softened glass sheet onto the inner mold, transferring the glass sheet on the inner mold to the outer mold, pressing the glass sheet placed on the outer mold against the forming face of the preliminary forming mold, and holding the glass sheet in the preliminary bent shape by the preliminary forming mold, the main forming step includes transferring the glass sheet in the preliminary bent shape onto the main forming supporting mold, and pressing the glass sheet against the forming face of the main forming mold while an under surface of the glass sheet is supported by the forming face of the lower mold while the edge portions of the glass sheet are placed on the main forming supporting mold, the outer mold of the preliminary forming supporting mold has a flapping mechanism comprising a fixed frame and at least one movable frame connected to respective ends of the fixed frame to be swingable, and the preliminary forming step includes flapping the glass sheet placed on the outer mold by the at least one movable frame, and the flapping of the glass sheet by the at least one movable frame is commenced by lowering the inner mold toward the outer mold while a lower forming apparatus for preliminary forming is moving, wherein the inner mold of the preliminary forming supporting mold has a flapping mechanism comprising a fixed frame and at least one movable frame connected to respective ends of the fixed frame to be swingable, and the preliminary forming step includes flapping the glass sheet placed on the inner mold by the at least one movable frame of the inner mold.