Locking aperture for molded pulp container

Claim 1

A MOLDED PULP CONTAINER COMPRISING A BOTTOM MEMBER AND A TOP MEMBER ADAPTED TO COME TOGETHER IN A CLOSED POSITION, A LOCKING FLAP HINGED TO ONE MEMBER, A MALE LOCKING PORTRUSION FORMED ON THE LOCKING FLAP, THE OTHER MEMBER INCLUDING A SUBSTANTIALLY PLANAR BASE PORTION AND AN INTEGRAL WALL PORTION AT AN OBTUSE ANGLE TO THE SUBSTANTAILLY PLANAR BASE PORTION FORMING THEREWITH A CORNER STRUCTURE IN THE PLANE OF THE BASE PORTION, THE WALL PORTION AND THE LOCKING FLAP ADAPTED TO LIE CLOSELY ADJACENT EACH OTHER WHEN THE MEMBES ARE IN THE CLOSED POSITION WITH THE LOCKING FLAP INSIDE THE WALL PORTION, A FEMALE LOCKING APERTURE FORMED IN THE WALL PORTION TO RECEIVE THE MALE LOCKING PROTRUSION WHEN THE MEMBERS ARE IN THE CLOSED POSITION, A STEP IN THE OTHER MEMBER FORMED BY A RISER PORTION OUT OF THE PLANE OF THE WALL PORTION AND JOINED AT ONE EDGE TO THE BASE PORTION AND A NARROW TREAD PORTION JOINING THE OPPOSITE EDGE OF THE RISER PORTION WITH THE WALL PORTION, THE JUNCTURE OF THE ONE EDGE OF THE RISER PORTION WITH THE BASE PORTION FORMING A CONTINUATIONOF THE CORNER STRUCTURE BETWEEN THE WALL PORTION AND THE BASE PORTION, THE CONTINUATION OF THE CORNER STRUCTURE BEING IN THE PLANE OF THE SUBSTANTIALLY PLANAR BASE PORTION, THE WIDTH OF THE NARROW TREAD PORTION BETWEEN THE OPPOSITE EDGE OF THE RISER PORTION AND THE WALL PORTION BEING BETWEEN ONE AND TEN TIMES THE THICKNESS OF THE WALL PORTION, THE FEMALE LOCKING APERTURE EXTENDING THROUGH THE WALL PORTION FOR AT LEAST EIGHTY PERCENT OF ITS OPEN AREA AND THROUGH AT LEAST PART OF THE NARROW TREAD PORTION FOR NO MORE THAN TWENTY PERCENT OF ITS OPEN AREA, AND THE APERTURE BEING DEFINED BY SMOOTH, FORMING DIE ESTABLISHED EDGES CHARACTERIZED BY AN ABSENCE OF SIGNIFICANT ACCUMULATION OF PULP DISTRIBUTED AS A FEATHERED EDGE WHEREBY THE THICKNESS OF THE MOLDED PULP CONTAINER IS SUBSTANTIALLY UNIFORM CLOSELY ADJACENT THE EDGES OF THE APERTURE.