Adjustable supporting surfaces

Claim 1

A SUPPORTING SURFACE ARRANGEMENT FOR PROVIDING A FIRE RESISTANT ADJUSTABLE SHELVING STRUCTURE COMPRISNG A PLURALITY OF SHELVES FITTED TOGETHER AND ADJUSTABLY SUPPORTED BY VERTICAL UPRIGHTS, SAID SHELVES CONSISTING OF A SHELF HAVING CORNER PORTIONS WITH A RIGHT ANGLED NOTCH AT EACH OF SAID CORNER PORTIONS, A VERTICAL UPRIGHT, SQUARE INCROSS-SECTION, POSITIONED IN SAID RIGHT ANGLED NOTCH AT EACH OF SAID CORNER PORTIONS, THE LONGITUDIAL EDGES OF SAID NOTCHES TERMINATING SUBSTANTIALLY MEDIALLY OF THE RESPECTIVE ADJACENT SIDES OF SAID UPRIGHTS, MEANS COMPRISING A BRACKET OF CORRESONDING RIGHT ANGULAR SHAPE IN CROSS-SECTION AND DISPOSED BETWEEN SAID SHELVES AND UPRIGHT AND POSITIONED IN SAID RIGHT ANGULAR NOTCH, SAID BRACKET MEANS HAVING ARMS EXTENDNG AT RIGHT ANGLES TO EACH OTHER AND ENGAGING AND EXTENDNG ALONG THE ADJACENT SIDES OF SAID SHELVES AT THEIR CORNER EDGES IN SUPPORTING RELATION THERETO, AND DETACHABLE MEANS FOR SECURING SAID BRACKET MEANS TO THE UPRIGHT POSITIONED IN SAID RIGHT ANGLED NOTCH, SAID ADJOINING SHELVES BEING SPACED APART BY SAID BRACKET ARMS TO PROVIDE A SLOT OPENING THEREBETWEEN FOR THE PASSAGE OF FIRE EXTINGUISHING FLUID.