Ceiling constructions for furnaces

Claim 1

IN A TUNNEL KILN, IN WHICH THE LENGTH OF THE FURNACE IS MANY TIMES ITS WIDTH, AND HAVING A MAIN SUPPORTING STRUCTURE, A GAS-TIGHT CEILING CONSTRUCTION COMPRISING A PLURALITY OF ABUTMENT BRICKS HUNG FROM THE SUPPORTING STRUCTURE OF THE FURNACE BY THEIR UPPER ENDS AND ARRANGED IN ROWS WHICH ARE DISPOSED TRANSVERSELY OF THE FURNACE AND SPACED FROM EACH OTHER LONGITUDINALLY THEREOF, A PLURALITY OF SUSPENDED BRICKS ARRANGED IN ROWS BETWEEN SAID ROWS OF ABUTMENT BRICKS AND SUPPORTED THEREBY, SAID ABUTMENT AND SUSPENDED BRICKS HAVING MUTUALLY ENGAGING, SUBSTANTIALLY VERTICAL AND PLANAR SIDE FACES FAACING TRANSVERSELY OF SAID FURNACE, SAID SIDE FACES CONSTITUTING THE SOLE SURFACES OF ENGAGEMENT IN THE TRANSVERSE DIRECTION, FLEXIBLE MEANS FOR MAINTAINING SAID BRICKS IN SAID TRANSVERSE ENGAGEMENT TO GAS SEAL WITH EACH OTHER, SAID SUSPENDED BRICKS HAVING ALONG BOTH SIDES ADJACENT SAID ABUTMENT BRICKS DOWNWARDLY FACING, HORIZONTAL, ENGAGEMENT SURFACES, SAID ABUTMENT BRICKS HAVING CORRESPONDINGLY UPWARDLY FACING, HORIZONTAL SUPPORT SURFACES ADJACENT THEIR LOWER ENDS DISPOSED FOR COOPERATIVE ENGAGEMENT BY SAID ENGAGEMENT SURFACES OF SAID ABUTMENT BRICKS, SAID HORIZONTAL ENGAGEMENT SURFACES OF EACH SUSPENDED BRICK BEING IN CONTINUOUS SURFACE-TO-SURFACE GAS SEALING ENGAGEMENT WITH SAID HORIZONTAL SUPPORT SURFACES OF SAID ABUTMENT BRICKS IN THE ROWS ON OPPOSITE SIDES THEREOF, SAID ABUTMENT BRICKS AND SUSPENDED BRICKS HAVING MUTUALLY FACING, SUBSTANTIALLY VERTICAL SIDE-SURFACES ADJACENT SAID HORIZONTAL SURFACES AND FACING LONGITUDINALLY OF THE FURNACE, SAID BRICKS BEING DISPOSED WHEN SAID FURNACE IS INITIALLY CONSTRUCTED SUCH THAT SAID MUTUALLY FACING, VERTICAL SIDE-SURFACES ARE SPACED FROM EACH OTHER BY AN AMOUNT SUBSTANTIALLY EQUAL TO THE EXPANSION OF SAID BRICKS BETWEEN THEIR CENTERS OF GRAVITY FROM ROW TO ROW WHEN SAID FURNACE IS HEATED TO OPERATING TEMPERATURE, SO THAT THE CENTER OF GRAVITY OF EACH INDIVIDUAL BRICK REMAINS SUBSTANTIALLY UNDISTURBED IN THE LONGITUDINAL DIRECTION OF SAID FURANCE, WHILE SAID CONTINUOUS SURFACE-TO-SURFACE SEALING ENGAGEMENT IS MAINTAINED BETWEEN SAID HORIZONTAL SURFACES OF SAID ABUTMENT BRICKS AND SAID SUSPENDED BRICKS, RESPECTIVELY, DESPITE RELATIVE MOVEMENT BETWEEN SAID HORIZONTAL SURFACES DURING EXPANSION OR CONTRACTION OF SAID BRICKS.