Take-down rack-type metal shelves

Claim 1

IN A SHELF STRUCTURE, A PLURALITY OF SPACED VERTICAL SHELF-SUPPORTING MEMBERS HAVING VERTICALLY SPACED RECESSES THEREIN, A SHELF FITTING BETWEEN SAID MEMBERS AND HAVING A MARGINAL PORTION BENT TWICE AT RIGHT ANGLES TO FORM A U-SHAPED CHNNEL DEIFFNED BY A VERTICAL PERIPHERAL WALL AND ADJACENT HORIZONTAL WALLS, LOCKING DEVICED FOR SECURING SAID SHELF IN SELECTED POSITION ON SAID SUPPORTING MEMBERS, EACH LOCKING DEVICE COMPRISING A FLEXIBLE ELASTIC BALDE HAVING A WIDTH SLIGHTLY LESS THAN THE DISTANCE BETWEEN SAID HORIZONTAL WALLS OF SAID CHANNEL AND BENT BACK OF ITSELF IN THE FORM OF A V WITH A NOSE PORTION FORMED BY THE POINT OF SAID V, A FIRST LEG PORTION SLIDABLY ENGAGING SAID VERTICAL WALL OF SAID CHANNEL AND A SECOND LEG PORTION HAVING AT ITS END AN OUTWARDLY BENT TAB PORTION PROJECTING AWAY FROM SAID VERTICAL WALL OF THE CHANNEL AND OF LESS WIDTH THAN THE SAID BRANCHES AND A PLURALITY OF CATCHES FORMED BY STAMPED OUT PORTIONS IN AT LEAST ONE OF SAID HORIZONTAL WALLS OF SAID CHANNEL, SAID CATCHES BEING SPACED FROM SAID VERTICAL WALL OF SAID CHANNEL AND SLIDABLY RETAINING SAID LOCKING DEVICE BETWEEN SAID CATCHES AND SAID VERTICAL WALL OF SAID CHANNEL FOR SLIDING MOVEMENT BETWEEN A LOCKING POSITION IN WHICH SAID NOSE PORTION PROJECTS BEYOND SAID SHELF AND INTO A SAID RECESS IN AN ADJACENT SUPPORTING MEMBER AND A RETRACTED POSITION.