Self-releasing form for casting concrete slabs

Claim 1

IN A SLAB CASTING FORM FOR MOLDING FLAT SLABS OF CONCRETE SUCH AS ARE USED IN BUILDING CONSTRUCTION AND THE LIKE, A FRAME CONSTITUTING A MOLD CRADLE, A MOLD PAN OF SHEET METAL HAVING UPTURNED EDGES MOUNTED HORIZONTALLY IN SAID CRADLE AND ADAPTED TOI MOLD THE BOTTOM AND SIDES OF THE LOWER PART OF A SLAB BEING CASTING THEREIN, SIDE FORMS OF SHEET METAL INTERFITTING WITHIN SAID UPTURNED EDGES OF SAID PAN AND EXTENDING UPWARDLY THEREFROM TO MOLD THE SIDES OF THE UPPER PART OF A SLAB BEING CAST THEREIN, A PLURALITY OF VERTICALLY DISPOSED SHEET METAL HINGE PLATES SECURED TO AND EXTENDING OUTWARDLY FROM EACH OF SAID UPWARDLY EXTENDING SIDE FORMS, SAID HINGE PLATES BEINE PROVIDED AT THEIR OUTER LOWER EDGES WITH HORIZONTALLY DISPOSED SLOTS, HINGE PINS CARRIED BY SAID FRAME AND DISPOSED TO SLIDABLY ENGAGE SAID SLOTS IN SAID HINGE PLATES IN MANNER TO PROVIDE LOST MOTION HINGES FOR UPWARD AND OUTWARD PIVOTING MOVEMENT OF SAID SIDE FORM AND FOR OUTWARD TRANSLATORY MOVEMENT THERETO IN RELEASING A SLAB CAST IN SAID FORM, MANUALLY ACTUATED LOCKING BOLTS SLIDABLY MOUNTED ON SAID FRAME ADJACENT TO SAID HINGE PLATES, LATCHES SECURED TO SAID HINGE PLATES IN POSITION TO BE ENGAGED BY SAID LOCKING BOLTS WHEN SAID SIDE FORM IS IN CASTING POSITION, AND A CONTINUOUS SHEET METAL COVER PLATE EXTENDING FROM SAID SIDE FROM OUTWARDLY OVER SAID HINGE PLATES IN MANNER TO COVER PLATE BEING SECURED TO BOTH SAID SIDE BOLTS, SAID COVER PLATE BEING SECURED TO BOTH SAID SIDE FORM AND SAID HINGE PLATES TO CONSTITUTE THEREWITH A REINFORCED STRUCTURE ADAPTED TO OBVIATE DISTORTION OF SAID SAID FORM, THE ARRANGEMENT BEING SUCH THAT WHEN A SLAB CAST IN SAID FORM HAS SOLIDIFIED SAID LOCKING BOLTS MAY BE DISENGAGED FROM SAID LATCHES WHEREUPON SAID SIDE FORMS ARE FREE TO MOVE UPWARD WITH THE SLAB AS IT IS LIFTED FROM SAID MOLD PAN AND ALSO TO MOVE OUTWARDLY FROM THE SIDES OF THE SLAB TO PROVIDE CLEARANCE FOR REMOVAL OF THE SLAB FROM THE FORM.