Insulated container and closure therefor

Claim 1

AN INSULATED CONTAINER OF RESILIENT THERMOPLASTIC MATERIAL COMPRISING AN INNER CONTAINER AND A SURROUNDING OUTER SHELL HAVING AN INSULATING SPACE THEREBETWEEN, A NECK PORTION CONNECTED TO SAID CONTAINER AND CASING AND FORMING A MOUTH FOR THE INSULATED CONTAINER AND HAVING AN OUTER RIM, AND A CLOSURE FOR SAID MOUTH INCLUDING A HOLLOW STOPPER PORTION HAVING AN OPENING AT ITS OUTER END LEADING TO THE INTERIOR THEREOF ADAPTED TO BE INSERTED INTO THE NECK PORTION, AN ANNULAR PORTION EXTENDING OUTWARDLY FROM THE STOPPER, A DEPENDING WALL AT THE EDGE OF THE ANNULAR PORTION HAVING MEANS INTERLOCKING WITH SAID RIM TO HOLD THE CLOSURE THERETO, THE ANNULAR PORTION HAVING SEALING RIB PORTION PRESSED AGAINST THE END OF SAID NECK PORTION TO SEAL THE MOUTH, AND A CAP FOR CLOSING THE OPENING AT THE OUTER END OF THE STOPPER, SAID CAP HAVING A PORTION ENGAGING THE OUTER FACE OF THE ANNULAR PORTION AND A FLANGE INSERTED INTO THE OPENING, SAID FLANGE HAVING RIB OF RIGHT TRIANGULAR CROSS-SECTION EXTENDING INTO A CORRESPONDINGLY SHAPED COOPERATING GROOVE FORMED IN SAID ANNULAR PORTION ABOVE THE STOPPER PORTION WITH THE BASE OF THE TRIANGLE FACING THE OUTER END OF THE STOPPER AND THE HYPOTENUSE OF THE TRIANGLE FACING THE SEALING PORTION OF THE STOPPER.