Concrete slab key joint forming strip

Claim 1

A CONCRETE FORM OF THE TYPE USED IN FORMING A KEY CONTRACTION JOINT BETWEEN ADJACENT CONCRETE SLABS COMPRISING IN COMBINATION WITH A PLURALITY OF ALIGNED SUBSTANTIALLY VERTICAL STAKES SET WITH THEIR UPPER ENDS UNIFORMLY BELOW GRADE LEVEL, AN ELONGATED SHEET METAL STRIP SUPPORTED ON THE STAKES AND HAVING LONGITUDINAL UPPER AND LOWER CO-PLANAR PORTIONS ABUTTING THE STAKES AND ALSO HAVING A KEY DEFORMATION PORTION INTERPOSED BETWEEN AND CONNECTED TO THE UPPER AND LOWER PLANAR PORTIONS, THE UPPER PLANAR PORTION HAVING A FOLDED-OVER PORTION AT THE UPPER EDGE THEREOF EXTENDING IN A DIRECTION OPPOSITE TO THE DIRECTION OF THE KEY DEFORMATION PORTION, SUCH FOLDED-OVER PORTION EXTENDING DOWNWARDLY AGAINST THE UPPER PLANAR PORTION TO FORM A NARROW LONGITUDINAL STRAIGHT EDGE EXTENDING AT GRADE LEVEL, AND SUCH BENT-OVER PORTION EXTENDING OUTWARDLY IN A DIRECTION OPPOSITE TO THE DIRECTION OF THE KEY DEFORMATION PORTION AND THENCE DOWNWARDLY TO FORM A LONGITUDINAL INVERTED L-SHAPED FLANGE POSITIONED WELL BELOW GRADE LEVEL, SAID FLANGE EMBRACING AND BEING SUPPORTED ON THE UPPER ENDS OF THE STAKES.