Apparatus for bending and tempering glass

Apparatus for bending and tempering glass sheets comprising:

• a heating chamber for heating glass sheets to a sufficiently high temperature to permit tempering thereof;
• a conveyor for conveying glass sheets generally horizontally through the heating chamber;
• a holder positioned within the heating chamber above the conveyor to receive a heated glass sheet therefrom;
• said holder having a downwardly facing surface of a predetermined shape against which a differential gas pressure supports the heated sheet of glass received from the conveyor in preparation for bending;
• a mold having a generally open center and a curved shape over at least a substantial portion thereof with a greater curvature than said predetermined shape of the holder surface;
• said mold being movable horizontally to a position within the heating chamber between the holder and the conveyor to receive the heated glass sheet at tempering temperature from the holder for substantial sag bending of the glass sheet on the mold solely under gravity;
• a quench unit for tempering bent glass sheets;
• and an actuator for moving the mold from the heating chamber to the quench unit in a time to control the extent of bending before tempering of the glass sheet.

Apparatus for bending and tempering glass sheets comprising:

• a heating chamber for heating glass sheets to a sufficiently high temperature to permit tempering thereof;
• a conveyor for conveying glass sheets generally horizontally through the heating chamber;
• a vacuum holder positioned within the heating chamber above the conveyor and having a downwardly facing surface of a predetermined shape with spaced openings at which a vacuum is selectively drawn;
• a support for lowering and raising the holder;
• the support lowering the holder toward the conveyor to facilitate pickup of a heated glass sheet therefrom by a vacuum drawn at the holder surface openings;
• the support raising the holder with the glass sheet thereon to support the glass sheet within the heating chamber above the conveyor in preparation for bending;
• a mold having a generally open center and a curved shape over at least a substantial portion thereof with a greater curvature than said predetermined shape of the holder surface;
• said mold being movable horizontally to a position within the heating chamber between the raised holder and the conveyor to receive the heated glass sheet at tempering temperature from the holder for substantial sag bending of the glass sheet on the mold solely under gravity;
• a quench unit for tempering bent glass sheets;
• and an actuator for moving the mold from the heating chamber to the quench unit in a time to control the extent of bending before tempering of the glass sheet.

Apparatus for bending and tempering glass sheets comprising:

• a heating chamber for heating glass sheets to a sufficiently high temperature to permit tempering thereof;
• a roller conveyor including horizontally extending rolls for conveying glass sheets generally horizontally through the heating chamber;
• a holder positioned within the heating chamber above the conveyor and having a downwardly facing surface of a predetermined shape at which a vacuum is selectively drawn;
• auxiliary lifters that are raised and lowered between the rolls below the holder;
• the auxiliary lifters being raised to lift a heated glass sheet on the conveyor upwardly toward the holder to facilitate pickup thereof by a vacuum drawn at the holder surface openings;
• the auxiliary lifters thereafter being lowered such that the holder supports the glass sheet within the heating chamber above the conveyor in preparation for bending;
• a mold having a generally open center and a curved shape over at least a substantial portion thereof with a greater curvature than said predetermined shape of the holder surface;
• said mold being movable horizontally to a position within the heating chamber between the holder and the conveyor to receive the heated glass sheet at tempering temperature from the holder for substantial sag bending of the glass sheet on the mold solely under gravity;
• a quench unit for tempering bent glass sheets;
• and an actuator for moving the mold from the heating chamber to the quench unit in a time to control the extent of bending before tempering of the glass sheet.

Apparatus for bending and tempering glass sheets comprising:

• a heating chamber for heating glass sheets to a sufficiently high temperature to permit tempering thereof;
• a conveyor for conveying glass sheets generally horizontally through the heating chamber;
• a holder positioned within the heating chamber above the conveyor and having a downwardly facing planar surface with spaced openings at which a vacuum is drawn to support a heated sheet of glass received from the conveyor such that the glass sheet is positioned within the heating chamber above the conveyor in preparation for bending;
• a mold having a generally open center and a curved shape;
• said mold being movable horizontally to a position within the heating chamber between the holder and the conveyor to receive the heated glass sheet from the holder for substantial sag bending of the glass sheet on the mold solely under gravity;
• a quench unit for tempering bent glass sheets;
• and an actuator for moving the mold from the heating chamber to the quench unit in a time to control the extent of bending before tempering of the glass sheet.

Apparatus for bending and tempering glass sheets comprising:

• a heating chamber for heating glass sheets to a sufficiently high temperature to permit tempering thereof;
• a conveyor for conveying glass sheets generally horizontally through the heating chamber;
• a holder positioned within the heating chamber above the conveyor and having a downwardly facing surface of a curved shape;
• means for initially bending a heated glass sheet received from the conveyor against the curved surface of the holder and for supporting the glass sheet in contact with the holder surface in preparation for further bending;
• a mold having a generally open center and a curved shape over at least a substantial portion thereof with a greater curvature than said curved shape of the holder surface;
• said mold being movable horizontally to a position within the heating chamber between the holder and the conveyor to receive the heated glass sheet at tempering temperature from the holder for further bending of the glass sheet on the mold solely under gravity;
• a quench unit for tempering bent glass sheets;
• and an actuator for moving the mold from the heating chamber to the quench unit in a time to control the extent of bending before tempering of the glass sheet.

Apparatus for bending and tempering glass sheets comprising:

• a heating chamber for heating glass sheets to a sufficiently high temperature to permit tempering thereof;
• a roller conveyor including elongated rolls for conveying glass sheets generally horizontally through the heating chamber;
• a pair of continuous drive loops that support and frictionally drive the conveyor rolls;
• a pair of spaced support surfaces on which the pair of drive loops are respectively supported and slidably driven;
• a holder positioned within the heating chamber above the conveyor and having a downwardly facing surface of a predetermined shape including spaced openings at which a vacuum is selectively drawn to support a heated sheet of glass received from the conveyor such that the glass sheet is positioned within the heating chamber above the conveyor in preparation for bending;
• a mold having a generally open center and a curved shape over at least a substantial portion thereof with a greater curvature than said predetermined shape of the holder surface;
• said mold being movable horizontally to a position within the heating chamber between the holder and the conveyor to receive the heated glass sheet at tempering temperature from the holder for substantial sag bending of the glass sheet on the mold solely under gravity;
• a quench unit for tempering bent glass sheets;
• and an actuator for moving the mold from the heating chamber to the quench unit in a time to control the extent of bending before tempering of the glass sheet.

Apparatus for bending and tempering glass sheets comprising:

• a heating chamber for heating glass sheets to a sufficiently high temperature to permit tempering thereof;
• a roller conveyor including elongated rolls for conveying glass sheets generally horizontally through the heating chamber;
• a pair of continuous drive loops that support and frictionally drive the conveyor rolls;
• a pair of spaced support surfaces on which the pair of drive loops are respectively supported and slidably driven;
• a holder positioned within the heating chamber above the conveyor and having a downwardly facing surface of a predetermined shape including spaced openings;
• means for drawing a vacuum within the spaced openings of the holder so as to support a heated sheet of glass received from the conveyor such that the glass sheet is positioned within the heating chamber above the conveyor in preparation for bending;
• said vacuum drawing means including a control therefor so as to initially draw a greater vacuum to secure the glass sheet to the holder and so as to subsequently draw a lesser vacuum to maintain the glass sheet supported without deforming the glass sheet at the spaced openings of the holder surface;
• a mold having a generally open center and a curved shape over at least a substantial portion thereof with a greater curvature than said predetermined shape of the holder surface;
• said mold being movable horizontally to a position within the heating chamber between the holder and the conveyor to receive the heated glass sheet at tempering temperature from the holder for substantial sag bending of the glass sheet on the mold solely under gravity;
• a quench unit for tempering bent glass sheets;
• an actuator for moving the mold from the heating chamber to the quench unit in a time to control the extent of bending before tempering of the glass sheet;
• means for effecting a differential gas pressure at the upper and lower surfaces of the bent glass sheet on the mold to lift the bent glass sheet upwardly off the mold and thereby permit withdrawal of the mold from beneath the lifted glass sheet;
• and a conveyor for receiving the lifted glass sheet to provide movement thereof for cooling and delivery to an operator.