Coating glass sheets

Claim 1

IN A METHOD OF PROVIDING A REFRACTORY SHEET WITH A NON-UNIFORM METAL OXIDE FILM BY APPLYING TO THE SHEET A NON-UNIFORM METAL OXIDE FILM BY APPLYING TO THE SHEET SOFTENING TEMPERATURE OF THE SHEET A SPRAY OF A FILM FORMING COMPOSITION CAPABLE OF PRODUCING A METAL OXIDE FILM THEREON, THE IMPROVEMENT WHICH COMPRISES ORIENTING SAID SHEET IN A FIXED PLANE, APPLYING SAID SPRAY ABOUT A FIXED CENTRAL AXIS THEREOF TO A PORTION ONLY OF SAID SHEET FROM A POINT OF ORIGIN OF SAID SPRAY LOCATED IN A PLANE SPACED FROM THE PLANE OF SAID SHEET, ORIENTING THE DIRECTION OF SAID CENTRAL AXIS OF THE SPRAY IN A FIXED ANGULAR RELATION BETWEEN ON THE ORDER OF 15* AND ON THE ORDER OF 45* TO THE PLANE OF SAID SHEET, AND PROVIDING RELATIVE TRANSLATIONAL MOTION BETWEEN THE HEATED ORIENTED SHEET AND THE SPRAY AT THE POINT OF ORIGIN THEREOF AT A UNIFORM VELOCITY ALONG A LONGITUDINAL AXIS LYING IN ONE OF SAID PLANES, THE CENTRAL AXIS OF THE SPRAY BEING OBLIQUELY DISPOSED TRANSVERSELY OF THE AXIS OF RELATIVE MOVEMENT SO THAT A FILM OF NON-UNIFORM THICKNESS TRANSVERSELY OF THE AXIS OF RELATIVE MOVEMENT IS FORMED ON THE REFRACTORY SHEET, SAID THICKNESS VARYING FROM A MINIMUM ALONG A LINE INTERSECTED BY AN EDGE OF SAID SPRAY TRAVERSING THE SHORTEST POSSIBLE STRAIGHT LINE DISTANCE FROM THE POINT OF ORIGIN OF THE SPRAY TO THE PORTION AND INCREASING TRANSVERSELY OF SAID LONGITUDINAL AXIS TO A MAXIMUM ALONG AN EDGE OF THE SHEET INCLUDED IN SAID PORTION DIRECTLY EXPOSED TO SAID SPRAY.