ALEXANDRIA, Va., June 19 -- United States Patent no. 12,330,983, issued on June 17, was assigned to O'KEEFFE'S INC. (Brisbane, Calif.).
"Fire rated glass unit" was invented by William F O'Keeffe (Brisbane, Calif.) and Sean A Ross (Merced, Calif.).
According to the abstract* released by the U.S. Patent & Trademark Office: "An article of fire rated glass and method of producing the same prepared by selecting a sheet of clear float annealed glass of at least 19 millimeters in thickness and providing the edge of the sheet substantially free of imperfections. The glass sheet is then specially tempered at a temperature of at least 575 degrees Celsius for a period of at least 750 seconds, followed by a cooling step."
The patent was filed on May...