Method of and apparatus for manufacturing glass sheets on a gas support bed

Claim 1

APPARATUS FOR TREATING GLASS SHEET COMPRISING AN ELONGATED BED POSITIONED IN A FURNACE, AT LEAST A PORTION OF SAID BED HAVING GAS INLET AND GAS OUTLET OPENINGS IN THE SURFACE THEREOF, CONVEYOR MEANS FOR MOVING A SHEET OF GLASS OVER SAID BED IN THE LINGITUDINAL DIRECTION THEREOF, HEATING MEANS IN SAID FURNACE ABOVE SAID BED FOR HEATING SAID GLASS SHEET, MEANS FOR CIRCULATING HEATED GAS THROUGH SAID INLET OPENINGS OVER THE SURFACE OF SAID BED BETWEEN SAID BED AND SAID GLASS SHEET AND THEN OUT THROUGH SAID GAS OUTLET OPENINGS, SAID OUTLET OPENINGS BEING SIZED TO RESTRICT THE EXIT OF THE GAS FROM BETWEEN THE BED AND THE GLASS SHEET TO CREATE A BACK PRESSURE AND PROVIDE A SUBSTANTIALLY CONTINUOUS THIN GAS BLANKET OVER THE SURFACE OF SAID BED TO CAUSE THE GLASS SHEET TO BE SUPPORTED IN CLOSE SPACED RELATIONSHIP WITH SAID BED, SAID BED BEING FORMED OF AT LEAST ONE CERAMIC BLOCK OF NIN-METALLIC PARTICLES BONDED TOGETHER, SAID PARTICLES HAVING A XOEFFICIENT OF THERMAL EXPANSION NOT GREATER THAN 1X10**6 /C. AND SAID BLOCK HAVING A HIGH THERMAL SHOCK RESISTANCE SUFFICIENT THAT SAID BLOCK CAN BE EXPOSED TO ROOM TEMPERATURE AIR WHEN SAID BLOCK IS AT A TEMPERATURE OF ABOUT 1350* F. WITHOUT IMPAIRMENT THERETO.

Claim 3

A METHOD OF TREATING GLASS SHEET WHICH COMPRISES DISPOSING THE GLASS SHEET UPON A THIN SUBSTANITALLY CONTINUOUS BLANKET OF HOT GAS, FLOWING HOT GAS TO SAID BLANKET UNDER THE GLASS SHEET AT A PLURATLITY OF SPACED FEED POINTS, FLOWING GAS AWAY FROM SAID BLANKET UNDER THE GLASS SHEET AT A PLURALITY OF OUTLET POINTS SPACED FROM EACH OTHER AND FROM SAID FEED POINTS TO PROVIDE A GREATER TOTAL AREA BETWEEN SAID FEED POINTS AND SAID OUTLET POINTS THAN THE TOTAL AREA OF SAID INLET AND OUTLET POINTS AND PROVIDING A GREATER RESTRICTION TO THE FLOW OF GAS AWAY FROM SAID BLANKET THAN TO THE FLOW OF GAS TO SAID BLANKET TO CREATE A BACK PRESSURE AROUND SAID OUTLET POINTS AND MAINTAIN SAID SUBSTANTIALLY CONTINUOUS BLANKET OF HOT GAS UNDER SAID GLASS SHEET.

Claim 4

A METHOD OF TREATING GLASS SHEET WHICH COMPRISES DISPOSING THE GLASS SHEET UPON A THIN SUBSTANITALLY CONTINUOUS BLANKET OF HOT GAS, FLOWING HOT GAS TO SAID BLANKET UNDER THE GLASS SHEET AT A PLURATLITY OF SPACED FEED POINTS, FLOWING GAS AWAY FROM SAID BLANKET UNDER THE GLASS SHEET AT A PLURALITY OF OUTLET POINTS SPACED FROM EACH OTHER AND FROM SAID FEED POINTS TO PROVIDE A GREATER TOTAL AREA BETWEEN SAID FEED POINTS AND SAID OUTLET POINTS THAN THE TOTAL AREA OF SAID INLET AND OUTLET POINTS AND PROVIDING A GREATER RESTRICTION TO THE FLOW OF GAS AWAY FROM SAID BLANKET THAN TO THE FLOW OF GAS TO SAID BLANKET TO CREATE A BACK PRESSURE AROUND SAID OUTLET POINTS AND MAINTAIN SAID SUBSTANTIALLY CONTINUOUS BLANKET OF HOT GAS UNDER SAID GLASS SHEET.