This invention relates to apparatus and to a method for forming heated glass sheets.
1. Background Art
U.S. Pat. Nos. 5,498,275, 5,556,444, and 5,697,999 of Reunamaki disclose a glass sheet forming system for forming heated glass sheets during conveyance along a direction of movement of the glass sheet through the system. The forming is provided by lower and upper sets of deformable rolls that are vertically aligned with each other along the direction of conveyance and supported by associated members that are movable to move the lower and upper sets of rolls between a flat condition for receiving a heated glass sheet from an associated furnace and a curved condition for forming the glass sheet to a curved shape along a direction transverse to the direction of conveyance. Other glass sheet forming that is performed during movement of the glass along a direction of conveyance is disclosed by U.S. Pat. No. 4,883,527 McMaster et al. and U.S. Pat. No. 5,009,693 Freidel et al.
2. Disclosure of Invention
An object of the present invention is to provide improved apparatus for forming glass sheets.
In carrying out the above object, the apparatus constructed in accordance with the invention includes a furnace having a heating chamber and also includes a conveyor for conveying glass sheets along a direction of conveyance through the heating chamber of the furnace for heating to a forming temperature. A forming station of the apparatus is located downstream from the furnace along the direction of conveyance and includes a lower deformable roll forming conveyor having lower deformable rolls rotatable about associated axes at spaced intervals along the direction of conveyance. The forming station also includes an upper deformable roll forming press located above the lower deformable roll forming conveyor in an opposed relationship to receive a heated glass sheet from the furnace. The upper deformable roll forming press has upper deformable rolls rotatable about associated axes at spaced intervals along the direction of conveyance between the axes of the lower deformable rolls. An actuating mechanism of the system moves the lower deformable roll forming conveyor and the upper deformable roll forming press between flat shapes for receiving the heated glass sheet from the furnace and curved shapes for forming the heated glass sheet.
In the preferred construction, the lower deformable rolls each include a flexible shaft and roll discs spaced along the flexible shaft, and the upper deformable rolls each include roll discs. Furthermore, the apparatus includes a drive mechanism for rotatively driving the lower deformable rolls, and the upper deformable rolls are undriven idler rolls.
In one embodiment between each adjacent pair of lower deformable rolls, there is a single upper deformable roll whose axis is located along the direction of conveyance between the axes of the adjacent pair of lower deformable rolls. In the preferred construction of this embodiment, the axis of each upper deformable roll is located downstream from a midpoint along the direction of conveyance between the axes of the adjacent pair of lower deformable rolls.
Between each adjacent pair of lower deformable rolls of another embodiment, there are a plurality of upper deformable rolls whose axes are located along the direction of conveyance between the axes of the adjacent pair of lower deformable rolls.
The apparatus also may include a cooling station located downstream along the direction of conveyance from the forming station and having lower and upper quench heads for supplying quenching gas and also including a roll conveyor for conveying the formed glass sheet between the quench heads for cooling by the quenching gas supplied from the quench heads. This cooling station has an adjustment mechanism for adjusting the lower and upper quench heads and the roll conveyor of the cooling station to provide different curvatures for different curvatures of formed glass sheets.
Another object of the present invention is to provide a method for forming glass sheets.
In carrying out the immediately preceding object, the glass sheet forming method of the invention is performed by conveying a glass sheet along a direction of conveyance through a heating chamber of a furnace for heating to a sufficiently high temperature to permit forming of the glass sheet. The heated glass sheet is transferred from the furnace to a forming station between a lower deformable roll forming conveyor and an upper deformable roll forming press that respectively have lower deformable rolls rotatable about associated axes at spaced intervals along the direction of conveyance and upper deformable rolls rotatable about associated axes at spaced intervals along the direction of conveyance between the axes of the lower deformable rolls. The lower deformable roll forming face and the upper deformable roll forming conveyor are moved between flat shapes at which the heated glass sheet is received from the furnace and curved shapes for forming the heated glass sheet.
In performing the glass sheet forming, the lower deformable rolls are rotatively driven and the upper deformable rolls are undriven idler rolls.
The glass sheet forming may also include transferring of the formed glass sheet from the forming station to a conveyor of a cooling station between lower and upper quench heads for supplying quenching gas that cools the glass sheet. The lower and upper quench heads are adjustable to different curved shapes between different production jobs to permit cooling of different curved shapes of formed glass sheets.
The objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.