Adjustable supporting surfaces

Claim 1

A CENTRAL SUPPORT FOR A SECTIONAL METAL SHELF COMPRISING A CENTER POST SQUARE IN CROSS-SECTION; FOUR RECTANGULAR SHELF SECTIONS ARRANGED ABOUT AND SUPPORTED BY SAID CENTER POST; FOUR SUPPORTING BRACKETS SECURED ON SAID POST PERIPHERICALLY THEREOF WITH SIDE PORTIONS OF ADJACENT BRACKETS IN FACE CONTACTING RELATION; EACH SUPPORTING BRACKET HAVING A V-SHAPED PORTION SHAPED TO FIT A CORNER OF THE POST, EACH OF SAID RECTANGULAR SHELF SECTIONS HAVING A CORNER WITH A V-SHAPED NOTCH SNUGLY RECEIVING THE VSHAPED PORTION OF SAID BRACKET, SAID SHELF SECTIONS HAVING EDGE PORTIONS WHICH EXTEND DOWNWARDLY AND INWARDLY FORMING A CHANNEL WITH TURNED-UNDER LIP PORTIONS, SAID BRACKET COMPRISING A PAIR OF ARMS WHICH ARE OF SUBSTANTIALLY THE SAME WIDTH AS SAID SHELF EDGE PORTIONS AND EXTEND OUTWARDLY IN ENGAGEMENT WITH SAID SHELF EDGE PORTIONS, SAID ARMS HAVING PROJECTIONS THEREON ENGAGING AND SUPPORTING THE BOTTOM OF THE SHELF SECTIONS AND MEANS FOR SECURING THE ARMS TO THE SHELF EDGES.