Foldable measuring rules

Claim 1

IN A FOLDABLE MEASURING RULE, THE COMBINATION OF A FIRST MEASURING ELEMENT, A SINGLE LEAF OF A HINGE JOINT FORMED INTEGRALLY WITH SAID FIRST MEASURING ELEMENT, A SECOND MEASURING ELEMENT, A PAIR OF LEAVES OF SAID HINGE JOINT FORMED INTEGRALLY WITH SAID SECOND MEASURING ELEMENT AND SPACED SIDE BY SIDE FOR THE RECEPTION OF SAID SINGLE LEAF THEREBETWEEN, AND A PIVOT PIN FORMED INTEGRALLY WITH SAID SINGLE LEAF AND PROJECTING AN EQUAL DISTANCE FROM OPPOSITE FACES THEREOF FOR RECEPTION IN ALIGNED HOLES IN SAID PAIR OF LEAVES, SAID PIVOT PIN HAVING A HOLLOW CYLINDRICAL FORM AND SAID PROJECTION DISTANCE EQUALLING THE THICKNESS OF SAID LEAVES ON SAID SECOND MEASURING ELEMENT TO MATE WITH SAID HOLES THEREIN TO FORM AN ACCURATELY POSITIONED PIVOT BY INSERTION OF SAID SINGLE LEAF WITHIN SAID PAIR OF LEAVES, A FIRST PAIR OF WASHERS POSITIONED ASTRADDLE SAID HINGE JOINT, EACH OF SAID WASHERS OVERLYING ONE OF SAID PAIR OF LEAVES OF SAID HINGE JOINT, EACH WASHER OF SAID FIRST PAIR OF WASHERS BEING PROVIDED WITH AN INTEGRAL LUG PORTION SECURED TO SAID SECOND MEASURING ELEMENT, A SECOND PAIR OF WASHERS POSITIONED ASTRADDLE SAID JOINT, EACH OF SAID WASHERS OVERLYING A RESPECTIVE WASHER OF SAID FIRST PAIR OF WASHERS, EACH OF SAID WASHERS BEING PROVIDED WITH AN INTEGRAL LUG PORTION SECURED TO SAID FIRST MEASURING ELEMENT, SAID FIRST AND SAID SECOND PAIR OF WASHERS BEING PROVIDED WITH AXIALLY POSITIONED HOLES CORRESPONDING TO THE AXIS OF SAID HOLLOW PIVOT PIN, AND A RIVET EXTENDING THROUGH SAID HOLLOW PIN TO SECURE SAID FIRST AND SECOND PAIRS OF WASHERS AT THE AXIS OF SAID HINGE JOINT.