Patent ID: 6014873
Filing Date: 2000-01-18
Classification: C03B

Abstract:
A process for bend-shaping a glass plate by heating the glass plate to a temperature which is close to a softening temperature of the glass plate, while the glass plate is transferred in a transferring direction in a shaping furnace, to thereby bend the glass plate, by its own deadweight, the process comprising the steps of:positioning a plurality of hearth beds in proximity with one another so as to form a transferring surface;forming a substantially horizontal transfer portion and upwardly convex portion in said transferring surface, said upwardly convex portion extending in the transferring direction within a heating zone in the shaping furnace from the horizontal transfer portion to an exit portion of said heating zone, and said horizontal transfer portion and upwardly convex portion each being formed with a plurality of apertures through which a gas is blown to support the glass plate in a floating state;positioning a cooling zone outside said shaping furnace at a downstream side of said upwardly convex portion and in proximity with the shaping furnace, said cooling zone having a downward gradient face and being upwardly convexly shaped portion along substantially the entire length thereof;complexly bending the glass plate in the shaping furnace in the transferring direction and in a direction perpendicular to the transferring direction by transferring the glass plate along a complexly bending transferring surface portion of said transferring surface, said transferring surface comprising a first hearth bed of said plurality of hearth beds, said first hearth bed being positioned in said heating zone and having a bend-shaping surface, said first hearth bed having a complexly curved face which is upwardly projected with predetermined radius of curvatures along both an axis in the transferring direction and an axis in the direction perpendicular to the transferring direction, said first hearth bed being formed of a continuous surface having substantially the same radius of curvatures as the surface of the glass plate to be formed, and said first hearth bed having an upward gradient portion at at least an area near said exit portion of the heating zone, the glass plate being bent into a shape which substantially corresponds to the bend-shaping surface of the first hearth bed;transferring the glass plate through the shaping furnace by utilizing a driving chain having holders for holding the glass plate in a floating state and a pusher for pushing the held glass plate when the driving chain is driven in the transferring direction;cooling and strengthening the glass plate in said cooling zone by transferring the glass plate, which has been delivered through said exit portion of the heating zone, along a cooling transferring surface in said cooling zone which has a complexly curved face which is substantially the same as the shape of said first hearth bed so as to be substantially continuous to that of the first hearth bed and which has a downward gradient face along substantially the entire length of the cooling transferring surface; andholding the glass plate in the floating state by blowing a gas layer from the lower part of the first hearth bed when the glass plate is transferred along the first hearth bed.