In-lehr press bending
AssigneePPG Industries, Inc.
InventorsWilliam P. Cathers, Thomas J. Reese
Life of this patent
Estimating the term…
Abstract
Glass sheets are positioned on the shaping rail of an outline shaping mold for movement through a heating lehr and subsequent preliminary sag bending. The mold with the glass sheet supported thereon is then positioned between a pair of vertically aligned full surface pressing molds. The mold includes selected press surface areas that extend outside the perimeter of the outline mold. As the lower mold raises to lift the glass sheet off the outline mold, selected portions of the shaping rail move outwardly to allow the lower mold to pass through the outline mold. The glass sheet is then pressed between the upper and lower pressing molds.
Claims22
An outline bending mold for shaping heat softened sheet material comprising;
- a first rail portion having an elevational contour to support a first portion of said sheet inboard of the sheet perimeter;
- a second rail portion having an elevational contour to support a second portion of said sheet inboard of the sheet perimeter;
- a support frame to support said first and second rail portions;
- and
- means to move said second rail portion horizontally along said frame relative to said first rail portion from a first position wherein said second rail portion is inboard of the sheet perimeter to a second position wherein said second rail portion is outboard of said sheet perimeter.
An apparatus for shaping a sheet of material to a predetermined shape comprising;
- an outline sheet supporting mold having first and second rail portions with sheet engaging surfaces corresponding to the desired shape and elevational contour of said sheet inboard of the sheet perimeter;
- means to heat said sheet to its heat softening temperature;
- a lower shaping mold having a full surface press face with a press face outline having a first portion slightly smaller than a plan outline of said outline mold and selected second portions extending beyond said plan outline of said outline mold;
- means to separate said first rail portion relative to said second rail portion;
- and
- means to raise said lower mold relative to said outline mold such that said press face of said lower mold moves vertically through said separated outline mold.
A method of shaping heat softenable sheet material comprising;
- supporting said sheet on an outline mold having a shaping rail with plan outline corresponding to the shape of said glass sheet and having an upper shaping surface corresponding to the elevational contour of said sheet slightly inboard of said sheet perimeter;
- heating said sheet to its heat softening temperature so as to allow said sheet to gravity sag into substantial conformance with shaping surface of said outline mold;
- positioning said outline mold above a shaping mold with a full surface press face having a first outline portion slightly smaller than the plan outline of said outline mold and selected second outline portions extending beyond the plan outline of said outline mold;
- moving selected portions of said shaping rail vertically aligned with said selected second outline portions of said shaping mold outwardly relative to said outline mold so as to expand said outline mold;
- and
- raising said shaping mold relative to said outline mold such that said shaping mold press face passes through said shaping rail to lift said sheet from said upper shaping surface of said shaping rail and shape said sheet.
Dependencies are inferred from the claim text.