Method of controlling the thickness of float glass

Claim 1

IN A METHOD OF FORMING FLAT GLASS WHEREIN A LAYER OF MOLTEN GLASS IS SUPPORTED ON A BATH OF MOLTEN METAL CONTAINED BETWEEN SIDE WALLS OF A TANK IN A CONTROLLED ATMOSPHERE, THE IMPROVEMENT WHICH COMPRISES, SELECTING AN EDGE MATERIAL OTHER THAN SAID GLASS OF A DENSITY AND INTERFACIAL SURFACE TENSION RELATIONSHIP TO THE ATMOSPHERE, BATH AND GLASS SUCH THAT WHEN IN CONTACT WITH THE GLASS AND WALLS THE THICKNESS OF THE MOLTEN GLASS BODY IS CONTROLLED BY THE DEPTH OF THE MATERIAL AND SAID MATERIAL DOES NOT RUN OVER OR UNDER SAID GLASS AND SAID GLASS DOES NOT RUN OVER OR UNDER SAID MATERIAL, SAID MATERIAL BEING SUBSTANTIALLY CHEMICALLY INERT WITH RESPECT TO SAID GLASS AND SAID BATH, FLOATING A LAYER OF SAID MATERIAL ON THE METAL BATH BETWEEN THE MOLTEN GLASS AND THE SIDE WALLS, SO AS TO CONTACT BOTH SAID GLASS AND SAID WALLS, COVERING THE ENTIRE SURFACE OF THE BATH OUTSIDE THE MARGINS OF THE GLASS WITH SAID MATERIAL FOR AT LEAST THAT PORTION OF THE TANK IN WHICH SAID GLASS CAN FLOW, COOLING THE GLASS AT THE THICKNESS CONTROLLED BY THE DEPTH OF SAID MATERIAL, AND THEREAFTER REMOVING THE COOLED GLASS FROM THE BATH.