Glass manufacturing – Processes – Reshaping or surface deformation of glass preform
Reexamination Certificate
2000-02-15
2002-06-04
Colaianni, Michael (Department: 1731)
Glass manufacturing
Processes
Reshaping or surface deformation of glass preform
C065S106000, C065S107000, C065S245000, C065S253000, C065S287000, C065S289000
Reexamination Certificate
active
06397634
ABSTRACT:
TECHNICAL FIELD
The present invention relates to bend-shaping method and apparatus for a glass plate for transporting machines such as automobiles, ships, railways, airplanes and so on or for various usages for buildings and so on. In particular, the present invention relates to a bend-shaping method and apparatus for a glass plate suitable for bend-shaping a glass plate for windows of automobiles.
BACKGROUND ART
There has been known a method for bend-shaping a glass plate by heating the glass plate to around a softening temperature in a heating furnace and transferring the glass plate on a roller conveyor comprising a plurality of curved rollers (in, for example, U.S. Pat. No. 4,123,246). According to this method, the softened glass plate falls by its own weight and the glass plate is bent to meet a curvature of the rollers.
Further, there has been known a method for bend-shaping a glass plate by heating the glass plate to around a softening temperature in a heating furnace and transferring the glass plate by means of a plurality of rollers inclined in a transferring direction so that the transferring path is curved (in, for example, U.S. Pat. No. 4,820,327). According to this method, the softened glass plate falls by its own weight and the glass plate is bent to meet a curvature of the transferring path.
In description, “bend-shaping in a direction perpendicular to a transferring direction” means that the shape of a bend-shaped glass plate is a shape curved around an axis of transferring direction. In other words, the bend-shaped glass plate has a curved shape in cross-section taken vertically along the axis of transferring direction. “Bend-shaping in (along) a transferring direction” means that the shape of a bend-shaped glass plate is a shape curved around the axis perpendicular to the transferring direction. In other words, the bend-shaped glass plate has a curved shape in the cross-section taken vertically along the axis perpendicular to the transferring direction. With respect to the shape of a curved plane formed by a plurality of rollers as described after, phrases “bent in (along) a transferring direction”, “curved in a transferring direction” or the like have the same meaning as “bend-shaped in (along) a transferring direction”. A phrase “bend-shaped in a direction perpendicular to a transferring direction” is also applicable to description about a curved plane with respect to a direction perpendicular to a transferring direction.
In this description, “perpendicular to a certain direction” means a direction perpendicular to certain direction on a horizontal plane. Further, “upper” or “lower” means “upper” or “lower” with respect to a horizontal plane in this description.
In recent years, there is an increasing demand of production of small quantity and large variety in automobile industries, and glass plates having various curvatures are needed in response to models of automobiles. In a method described in U.S. Pat. No. 4,123,246, it was necessary to exchange rollers to those having a curvature corresponding to a model of automobile to be manufactured. The exchanging work took much time, and it was necessary to prepare rollers having a curvature required for a model to be manufactured. In this method, glass plates are transferred in a direction perpendicular to a direction to be bent. In bend-shaping a glass plate for a side window of an automobile, the direction of a
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side of the glass plate when it is fitted to an automobile, corresponds to the direction of extending of the rollers. In such state of fitting, a distortion appearing in the glass plate due to the contact of a roller having a distortion is conspicuous.
According to the method described in U.S. Pat. No. 4,820,327 ('327 method), it was necessary to change the arrangement of rollers so as to form a transferring path having a curvature which corresponds to a model to be manufactured.
Such change took much time.
Further, in the '327 method, the transferring direction of the glass plate is changed to a vertical direction. Therefore, the entire equipment to be used for the '327 method is inevitably large. Further, since the glass plate is transferred against the gravity, it is difficult to transfer the glass plate at a high speed, and a special mechanism for preventing the slippage of the glass plate has to be provided. Further, the transferring direction has to be changed from the vertical direction to a horizontal direction for the glass plate having been subjected to bend-shaping and tempering by cooling. A mechanism for changing the transferring direction is complicated, and there is a risk of a damage in the glass plate.
It is an object of the present invention to eliminate the disadvantages of the conventional techniques and to provide new bend-shaping method and apparatus for a glass plate which have been known conventionally.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of the above-mentioned problems and to provide a bend-shaping method for a glass plate comprising heating a glass plate to a bend-shaping temperature in a heating furnace and transferring the heated glass plate along a transferring plane formed by a plurality of rollers of a roller conveyor during which the glass plate is bend-shaped to have a predetermined curvature due to the dead weight of the glass plate, the bend-shaping method for a glass plate being characterized in that said rollers for forming a transferring plane are moved vertically depending on a position of transfer of the glass plate to form a curve in at least a part of the transferring plane so that a predetermined curved plane is formed at the position of transfer where the glass plate is, and the curved plane is shifted, as the propagation of a wave, from an upstream side to a downstream side of the roller conveyor whereby the glass plate is bend-shaped to have a predetermined curvature along the curved plane.
Further, the present invention provides a bend-shaping method for a glass plate comprising heating a glass plate to a bend-shaping temperature in a heating furnace and transferring the heated glass plate along a transferring plane formed by a plurality of rollers which are arranged side by side in a transferring direction of the glass plate during which the glass plate is bend-shaped to have a predetermined curvature due to the dead weight of the glass plate, the bend-shaping method for a glass plate being characterized in that a plurality of rollers at a position where the glass plate is transferred are moved vertically with the transfer of the glass plate so that a predetermined curved plane, which is curved in the transferring direction of the glass plate, is formed in at lease a part of the transferring plane by means of the plurality of rollers at said position, and each of said rollers is sequentially moved vertically with the transfer of the glass plate to shift the curved plane in the transferring direction of the lass plate with the transfer of the glass plate whereby the glass plate is bend-shaped so as to meet the curved lane during the transfer of the glass plate.
Further, the present invention provides a bend-shaping apparatus for a glass plate comprising a heating furnace for heating a glass plate to a bend-shaping temperature and a shaping means, located at a downstream side of the heating furnace, for bend-shaping the glass plate to have a predetermined curvature, the bend-shaping apparatus for a glass plate being characterized in that said shaping means comprises a roller conveyor comprising a plurality of rollers which form a transferring plane for transferring the glass plate, a vertical direction driving means for moving vertically the plurality of rollers, and a control means which controls the driving means to move vertically the rollers so that at least a part of the transferring plane is bent to have a curvature which corresponds to a curvature of the glass plate to be formed whereby a predetermined curved plane is formed by the rollers at the position where the transferred glass plate
Nemugaki Yoichi
Nomura Ken
Ohtsubo Nozomi
Takeda Takashi
Tomioka Masanori
Asahi Glass Company Ltd.
Colaianni Michael
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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