Method of bending and tempering glass sheets

A method of bending and tempering a glass sheet in a bending apparatus including a furnace for heating the sheet, a press bending station having upper and lower press members with opposed complementary shaping surfaces, the upper press member being a vacuum mould that is operable under reduced pressure, a shuttle carrier ring, and a quench station, the glass sheet having several portions and a periphery, and the shuttle carrier ring conforming in outline and elevation to the periphery of the sheet, wherein the method comprises the steps of:

• heating a glass sheet that is up to 4.2 mm thick to a heat-softened condition in said furnace, including heating at least one portion of the sheet to a higher temperature than another portion,
• conveying the sheet out of the furnace and into said press bending station,
• shaping the sheet by pressing it between said opposed complementary shaping surfaces provided on said upper and lower press members, with at least one of the press members being internally heated to maintain the shaping surface of the at least one press member at a temperature within the range of 200.degree. C. to 350.degree. C. during shaping to thereby bend the glass sheet in two directions disposed at right angles to one another,
• transferring the bent glass sheet onto said shuttle carrier ring, by supporting the bent glass sheet on the shaping surface of the upper press member by way of reduced pressure within the upper press member,
• lowering the lower press member relative to the upper press member,
• moving the shuttle carrier ring and the upper press member relative to each other to bring the shuttle carrier ring into position below the upper press member,
• lowering the upper press member towards the shuttle carrier ring in a controlled fashion until the upper press member is close to and slightly above the shuttle carrier ring, and
• releasing the bent glass sheet from the upper press member so that the bent glass sheet is accurately placed upon the shuttle carrier ring,
• transferring the bent glass sheet into the quench station while maintaining the shape of the bent glass sheet by supporting the bent glass sheet on the shuttle carrier ring,
• tempering the bent glass sheet, while still supported on the carrier ring, by quenching the surfaces of the sheet, and
• removing the bent and tempered glass sheet from the carrier ring.

A method of bending and tempering a glass sheet in a bending apparatus including a furnace for heating the sheet, a press bending station having upper and lower press members with opposed complementary shaping surfaces, the upper press member being a vacuum mould that is operable under reduced pressure, a shuttle carrier ring, and a quench station, the glass sheet having several portions and a periphery, and the shuttle carrier ring conforming in outline and elevation to the periphery of the sheet, wherein the method comprises the steps of:

• heating a glass sheet that is up to 4.2 mm thick to a heat-softened condition in said furnace, including heating at least one portion of the sheet to a higher temperature than another portion,
• subjecting the sheet to a preliminary bending step by conveying the sheet out of the furnace on a support shaped to impart a preliminary bend to the sheet and conveying the sheet into said press bending station,
• shaping the sheet by pressing it between said opposed complementary shaping surfaces provided on said upper and lower press members, with at least one of the press members being internally heated to maintain the shaping surface of the at least one press member at a temperature within the range of 200.degree. C. to 350.degree. C. during shaping to thereby bend the glass sheet in two directions disposed at right angles to one another,
• transferring the bent glass sheet onto said shuttle carrier ring, by
• supporting the bent glass sheet on the shaping surface of the upper press member by way of reduced pressure within the upper press member,
• lowering the lower press member relative to the upper press member,
• moving the shuttle carrier ring and the upper press member relative to each other to bring the shuttle carrier ring into position below the upper press member,
• lowering the upper press member towards the shuttle carrier ring in a controlled fashion until the upper press member is close to and slightly above the shuttle carrier ring, and
• releasing the bent glass sheet from the upper press member so that the bent glass sheet is accurately placed upon the shuttle carrier ring,
• transferring the bent glass sheet into the quench station while maintaining the shape of the bent glass sheet by supporting the bent glass sheet on the shuttle carrier ring,
• tempering the bent glass sheet, while still supported on the carrier ring, by quenching the surfaces of the sheet, and
• removing the bent and tempered glass sheet from the carrier ring.