Cycle of mold movement while press bending glass sheets

Apparatus for shaping a glass sheet comprising a conveyor defining a given path of travel, a furnace for heating said glass sheet to its deformation temperature, a shaping station located downstream of said furnace, said conveyor extending through said furnace and into said shaping station and a cooling station located immediately downstream of said shaping station;

• said shaping station comprising a lower lifting mold having an upwardly facing shaping surface, means for moving said lifting mold between a lowered position wherein said upwardly facing shaping surface is located immediately beneath said given path of travel and a lifted position wherein said upwardly facing shaping surface is located immediately above said given path of travel, an upper vacuum mold having a downwardly facing shaping surface that is apertured for drawing suction through the apertures of said shaping surface, and means for moving said upper vacuum mold between a parking position wherein its downwardly facing shaping surface is spaced above said given path of travel by a minimum distance greater than the thickness of said glass sheet and a maximum distance greater than the thickness of said glass sheet and a maximum distance sufficiently closely above said upwardly facing shaping surface of said lifting mold when said lifting mold occupies its lifted position to enable suction drawn through said apertures to lift said glass sheet by suction from said lifting mold and a raised position;
• means to control the application of suction through said apertures from the time that said lifting mold starts to move upwardly from its lowered position until after said upper vacuum mold moves upwardly to said raised position;
• a ring-like member and means to move said ring-like member from said cooling station in an upstream direction into said shaping station beneath said upper vacuum mold when said vacuum mold occupies its raised position, said raised position being sufficiently above said given path to provide clearance for said ring-like member between said upper vacuum mold and said given path;
• means to control said movement of said ring-like member in an upstream direction into said cooling station until said upper vacuum mold has moved upward into said raised position and said lower, lifting mold is not above said given path;
• means to control the application of said suction through said downwardly facing shaping surface of said upper vacuum mold until such time as said ring-like member is below said upper vacuum mold;
• and
• means synchronized with the stopping of said suction application to move said ring-like member in a downstream direction into said cooling station and to lower said lifting mold to its lowered position, and, when said ring-like member clears said shaping station, to lower said upper vacuum mold to its parking position to await the arrival of a succeeding glass sheet from said furnace.

A method of shaping a glass sheet comprising the steps of:

• positioning shaping surface of a vacuum shaping mold above and spaced from a generally horizontal path of travel, the shaping surface spaced from the path of travel a distance sufficient to move a sheet under the shaping surface and sufficient to draw by vacuum a sheet having portions shaped similar to corresponding portions of the shaping surface upwardly against the shaping surface of the shaping mold;
• moving a heat-softened glass sheet along the path of travel beneath the shaping surface of the vacuum mold;
• lifting a lower mold having a shaping surface having portions similar to the shaping surface of the vacuum shaping mold upwardly to lift and shape the sheet while maintaining the sheet spaced from the shaping surface of the vacuum shaping mold;
• applying vacuum through the shaping surface of the vacuum shaping mold to move the spaced shaped sheet upwardly off the shaping surface of the lower mold against the shaping surface of the vacuum shaping mold to shape the sheet to conform to the shaping surface of the vacuum mold.

An apparatus for shaping a glass sheet comprising:

• a vacuum shaping mold having a shaping surface;
• conveying means to move a sheet along a generally horizontal path of travel;
• means for mounting said vacuum mold above said conveying means with its shaping surface spaced from said conveying means a distance sufficient to position a sheet to be shaped beneath the shaping surface of said vacuum mold and sufficient to draw by vacuum a sheet having portions shaped similar to corresponding portions of the shaping surface of said vacuum mold upwardly against the shaping surface of said vacuum shaping mold;
• a lifting mold having a shaping surface having portions shaped similar to corresponding portions of said vacuum mold;
• means for mounting said mold beneath said conveying means and spaced from said vacuum shaping mold;
• and
• means for limiting upward movement of the lifting mold to a position where the vacuum mold by vacuum will draw the sheet upward.