Fire resistant door

Claim 1

A FIRE RESISTANT DOOR COMPRISING TWO PANELS OF HIGH DENSITY FIRE RESISTANT MATERIAL HAVING HIGH THERMAL INSULATION AND LOW COEFFICIENT OF EXPANSION, SAID PANELS BEING FIXED TO OPPOSITE SIDES OF A FRAME OF HIGH DENSITY FIRE RESISTANT MATERIAL ALSO HAVING HIGH THERMAL INSULATION AND LOW COEFFICIENT OF EXPANSION AND PROVIDING A SPACE BETWEEN THE PANELS, SAID FRAME COMPRISING STILES FLUSH WITH THE VERTICAL EDGES OF THE PANELS AND A HEAD RAIL LOCATED BETWEEN THE STILES AND THE TOP EDGE OF THE PANELS AND FLUSH THEREWITH, SAID STILES BEING COVERED ON THEIR EXPOSED EDGES BY DECORATIVE SHEETS, SAID SPACE BEING FILLED WITH FIRE RESISTANT MATERIAL OF LOW DENSITY, SAID LOW DENSITY FIRE RESISTANT MATERIASL COMPRISING BLOCKS LAID HORIZONTALLY IN THE SPACE BETWEEN THE PANELS, THE LOWERMOST BLOCK BEING FLUSH WITH THE BOTTOM EDGES OF THE PANELS AND STILES, DECORATIVE SHEETS COVERING THE EXPOSED FACES OF SAID PANELS, SAID SHEETS BEING MADE OF TIMBER AND IMPREGNATED WITH A FIRE RETARDANT MATERIAL, THE STILE AT ONE VERTICAL EDGE OF THE DOOR FORMED OF HIGHER DENSITY MATERIAL THAN THE REMAINDER OF THE FRAME, DOOR HINGES SECURED TO SAID LAST MENTIONED STILE, DOOR LOCKING MEANS MOUNTED IN THE DOOR MEDIALLY AND ADJACENT THE OTHER VERTICAL EDGE THEREOF, SAID HIGHER DENSITY STILE FORMED OF A DENSITY BONDED CALCIUM SILICATE COMPOSITION, THE REMAINDER OF THE FRAME AND THE PANELS FORMED OF A LESS DENSELY BONDED ASBESTOS COMPOSITION, AND SAID BLOCKS ARE FORMED OF A STILL LESS DENSELY BONDED CALCIUM SILICATE COMPOSITION.