Process for bend-shaping a glass plate and an apparatus for bend-shaping the glass plate

An apparatus for bend-shaping a glass plate wherein the glass plate is heated 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 by its deadweight the glass plate, the apparatus comprising:

• a heating zone and a cooling zone;
• a transferring surface having a plurality of beds positioned in proximity with one another and extending within said shaping furnace to an exit portion of the heating zone for transferring the glass plate, said transferring surface forming a substantially longitudinal transfer portion and an upwardly convex portion having an upward convex face and extending in the transferring direction, said cooling zone being located downstream from said upwardly convex portion and having a downward gradient face and said heating zone including a portion of said transferring surface which has an upward gradient face which is located upstream of said upwardly convex portion, each of said longitudinal transfer portion and upwardly convex portion being formed with a plurality of apertures through which a gas is blown to support the glass plate in a floating state;
• a shaping furnace located in the heating zone for heating the glass plate to a temperature which is close to a softening temperature of the glass plate;
• a complexly bending transferring surface positioned in the heating zone and downstream of said upwardly convex portion, which has a complexly curved face so as to upwardly project along both an axis of the transferring direction and an axis perpendicular to the transferring direction and which has an upward gradient portion at at least an area upstream of and in proximity with an exit of the shaping furnace, said complexly bending transferring surface being formed of a continuous surface having substantially the same radius of curvatures as the surface of the glass plate to be formed, wherein the glass plate is bent into a shape which substantially corresponds to that of the surface of the complexly bending transferring surface;
• a cooling transferring surface located outside said shaping furnace and in said cooling zone and which has a complexly curved face having substantially the same shape as the shape of the complexly bending transferring surface so as to be substantially continuous to that of the complexly bending transferring surface and which has a downward gradient portion with an upwardly convex shape extending the entire length of said cooling zone;
• and
• a glass plate cooling and strengthening mechanism located in the cooling zone and disposed near the cooling transferring surface;
• wherein the complexly bending transferring surface includes a hearth bed in the shaping furnace, said hearth bed being located downstream of said longitudinal transfer portion defining bend-shaping surfaces;
• and wherein the hearth bed is provided with a holding mechanism which ejects gas from the lower part of the complexly bending transferring surface to hold and transfer the glass plate in a floating state by a gas layer formed of gas, the holding mechanism further comprising a driving chain which is movable in the transferring direction, the driving chain comprising holders for holding the glass plate in the floating state and a pusher for pushing the held glass plate when the driving chain is driven.