Plastic container construction

Claim 1

A SEMI-RIGID PLASTIC CONTAINER HAVING A NECK AND A FINISH COMPRISING AN INTEGRAL EXTENSION OF SAID NECK, WHICH FINISH HAS AN OPENING DEFINING THE MOUTH OF THE CONTAINER AND IS ADAPTED TO RECEIVE A CLOSURE HAVING A PLUG PORTION FOR CLOSING THE MOUTH AND A COVER PORTION FOR COVERING THE END OF THE FINISH, SAID FINISH COMPRISING A PLUG-RE CEIVING WALL ABOUT THE MOUTH AND HAVING AN INNER SURFACE ADAPTED TO COOPERATE IN SEALING ENGAGEMENT WITH THE PLUG PORTION OF THE CLOSURE AND OUTER SURFACE OPPOSITE FROM SAID INNER SURFACE, A SHOULDER CIRCUMFERENTIALLY OF THE FINISH BETWEEN SAID PLUG-RECEIVING WALL AND SAID NECK AND EXTENDING RADIALLY OUTWARDLY RELATIVE TO THE AXIS OF THE OPENING, AND A FLANGE DEFINING A POURING LIP EXTENDING RADIALLY OUTWARDLY FROM SAID PLUG-RECEIVING WALL AT THE END OF SAID WALL OPPOSITE FROM SAID SHOULDER AND TERMINATING IN A PERIPHERAL EDGE HAVING A DIAMETER SUBSTANTIALLY EQUAL ANGLES TO AND DIVERGING IN OPPOSITE DIRECDER, SAID FLANGE BEING SUBSTANTIALLY NORMAL TO THE AXIS OF THE OPENING AND COOPERATING WITH SAID SHOULDER AND SAID PLUG-RECEIVING WALL TO DEFINE AN OUTWARDLY-OPEN GROOVE, SAID FLANGE AND SAID SHOULDER BEING ARRANGED AT SUBSTANTIALLY EQUAL ANGLES TO AND DIVERGING IN OPPOSITE DIRECTIONS OUTWARDLY FROM A PLANE CENTRALLY OF SAID GROOVE AND NORMAL TO THE AXIS OF THE OPENING, SAID CONTAINER BEING BLOW-MOLDED BY FLUID PRESSURE APPLIED AT SAID INNER SURFACE OF SAID PLUG-RECEIVING WALL WHEREBY SAID OUTER SURFACE OF SAID PLUG-RECEIVING WALL AND THE CORRESPONDING SURFACES OF SAID FLANGE AND SAID SHOULDER ARE DIEFORMED AND THE INNER SURFACE OF SAID PLUG-RECEIVING WALL AND THE CORRESPONDING SURFACES OF SAID FLANGE AND SAID SHOULDER ARE CHARACTERIZED BY SMOOTHLY-DRAWN BLOWMOLDED FEATURES, AND WHEREBY BY THE THICKNESS OF SAID FLANGE AND SAID SHOULDER ARE REDUCED RELATIVE TO THE THICKNESS OF SAID PLUG-RECEIVING WALL.