Process for the forming of glass plates and application of the process to obtain glazings with complex shapes

A process for convex bending of a glass plate comprising:

• heating the glass plate to a bending temperature while conveying the glass plate by a flat conveyor through a furnace;
• conveying the glass plate to a convex bending cell which is heated substantially to said bending temperature, and wherein a convex male mould and a concave annular female countermould are disposed in said convex bending cell, said convex male mould and said concave annular female mould being located at a fixed horizontal position and aligned along a vertical axis;
• performing a first preshaping step in which said glass plate is at least partially supported by said concave annular female countermould with said glass plate preshaped by gravity, including a sub-step of raising said glass plate by only said concave annular female countermould for a duration of time long enough so that a shape of said glass plate preshaped by gravity is substantially a final shape of said glass plate within said convex bending cell;
• performing a second preshaping step after said first preshaping step in which said glass plate is applied against only said convex male mould by a pneumatic pressure within said convex bending cell;
• and
• performing a pressing step after said second preshaping step in which said glass plate is pressed between said concave annular female countermould and said convex male mould within said convex bending cell.