Fluid quenching apparatus for producing a differentially toughened zone in a toughened glass

Claim 1

APPARATUS FOR THE MANUFACTURE OF OBJECTS OF TEMPERED GLASS COMPRISING AN ANNEALING FURNACE INCLUDING WALLS, HEATING ELEMENTS ARRANGED ALONGSIDE THE WALLS, MEANS WHEREBY A SHEET OF GLASS IS ADAPTED TO BE SUSPENDED IN THE FURNACE AND HELD ALONG ITS UPPER EDGE, MEANS TO RAISE THE GLASS SHEET FROM THE FURNACE AND TO INTRODUCE INTO THE FURNACE A BLOWING UNIT MOUNTED ABOVE THE FURNACE AND INTO WHICH THE HEATED SHEET IS DIRECTLY LIFTED AS THE SHEET IS RAISED FROM THE FURNACE, THE SAID BLOWING UNIT COMPRISING TWO GRIDS PROVIDED WITH AIR NOZZLES, MEANS TO SUPPLY AIR TO SAID NOZZLES, MEANS TO MOVE THE BLOWING UNIT IN ITS OWN PLANE SO THAT AIR JETS ON THE UNIT FOLLOW AN ORBITAL PATH WHILE BLOWING COOLING AIR ONTO THE SURFACE OF THE GLASS, TWO PERFORATED WIND BOXES IN THE ANNEALING FURNACE PLACED AT A VARIABLE DISTANCE FROM EACH OF THE SURFACES OF THE GLASS SHEET, AIR SUPPLY PIPES IN COMMUNICATION WITH BOXES TO SUPPLY AIR THERETO TO CAUSE AIR TO BE EJECTED FROM THE BOX AND CONTACT THE GLASS BEING HEATED TO COOL THE SAME LOCALLY.