Apparatus for bending glass sheets to sharp curvatures

Claim 1

Apparatus for shaping a glass sheet to a shape including a line of sharp curvature extending from one side edge to the other of said sheet comprising an outline mold of the skeleton type having an upper shaping surface conforming to the shape desired for said glass sheet after bending, a first electrode located on one side of said mold, a second electrode located on the other side of said mold, means adapted to couple said electrodes to an electrical power source, means for holding a flexible electroconductive ribbon in electroconductive relation to each of said electrodes and in fixed positions outside said mold in a vertical plane extending through said line of sharp bending for supporting said electroconductive ribbon in said vertical plane and across said mold in contact with the upper surface of a glass sheet mounted on said mold for bending, hold-down means located in said vertical plane intermediate one lateral side of said mold and said ribbon holding means to engage the upper surface of said ribbon in said vertical plane between a side of the mold and said ribbon holding means to apply a light downward force against said ribbon to hold said ribbon in contact with the upper surface of said glass sheet along the line of sharp bending as the latter sags, and means disposed in said vertical plane to engage the under surface of said ribbon inward of said position where said hold-down means engages said upper surface of said ribbon to maintain said ribbon in closely spaced relation to said glass sheet edges as the glass sheet sags along said line of sharp bending.