Carton blanks and resulting cartons with fulcrum locking of side panels

Claim 1

IN A BLANK FOLDABLE TO FORM A CARTON OR THE LIKE HAVING A PLURALITY OF CORNERS, THE AREA OF THE BLANK FOR ONE OF SAID CORNERS BEING FORMED BY FIRST AND SECOND OUTSIDE PANELS AND AN INSIDE PANEL TO WHICH SAID OUTSIDE PANELS ARE HINGED RESPECTIVELY ALONG ADJACENT INSIDE PANEL EDGES, SAID FIRST OUTSIDE PANEL HAVING HINGED TO ITS END EDGE AT SAID ONE CORNER A FLAP AT SAID ONE CORNER FOR RECEIVING TAB HAVING A TIP, SAID SECOND PANEL HAVING AN INTERNAL SLIT ADJACENT ITS END EDGE AT SAID ONE CORNER FOR RECEIVING SAID LOCKING TAB, THE IMPROVEMENT COMPRISING FULCRUM MEANS AT THE SAID END EDGE OF SAID SECOND PANEL AND INCLUDING A FULCRUM INTERMEDIATE THE OUTER EDGE OF SAID SECOND PANEL AND THE HINGE OF THE SECOND PANEL TO SAID INSIDE PANEL FOR INITIALLY PREVENTING AT LEAST COMPLETE ENTRY OF SAID TIP INTO SAID SLIT WHEN SAID FIRST PANEL IS FULLY FOLDED ABOUT ITS HINGE WITH THE SAIE INSIDE PANEL BUT THEN ALLOWING COMPLETE ENTRY OF SAID TIP INTO SAID SLIT WHEN THE SO FULLY FOLDED FIRST PANEL IS THEN FLEXED ABOUT THE FULCRUM TO CAUSE SAID TIP TO ROTATE TOWARD SAID INSIDE PANEL AND THROUGH SAID SLIT.