Vented lids for hot drink cups

Claim 1

A CLOSURE OF THE TYPE DESCRIBED COMPRISING A DISCLIKE BODY HAVING MEANS AT ITS PERIPHERY FOR EFFECTING ATTACHMENT TO A CUP OR OTHER CONTAINER, SAID MEANS BEING AN ANNULAR CURL, AN UPSTANDING ANNULAR BEAD RADIALLY INWARDLY OF SAID CURL, A FLOOR PORTION ENCOMPASSED BY SAID BEAD, SAID BEAD AND FLOOR PORTION DEFINING A CHAMBER, AN IMPERFORATE DISC HAVING ITS PERIPHERAL MARGIN FREELY RESTING ON SAID BEAD, SAID DISC BEING BONDED TO SAID FLOOR PORTION, THERE BEING INCLUDED VENTING ORIFICE MEANS OPENING THROUGH THE FLOOR POTION INTO THE CHAMBER FOR THE CONTINUOUS AND UNINTERRUPTED PASSAGE OF VAPOR PRESSURE INTO SAID CHAMBER FROM A CUP TO WHICH THE CLOSURE IS ADAPTED TO BE ATTACHED, ADDITIONAL VENTING ORIFICE MEANS FOR PERMITTING THE ESCAPE OF VAPOR PRESSURE FROM THE CHAMBER TO ATMOSPHERE, SAID FIRST-MENTIONED VENTING ORIFICE MEANS BEING AN OPENING IN THE FLOOR PORTION WHEREBY VAPOR PRESSURE IS FREE TO CONDENSE IN SAID CHAMBER AFTER PASSING THROUGH SAID OPENING, AND SAID SECOND-MENTIONED VENTING ORIFICE MEANS BEING DEFINED BETWEEN THE PERIPHERAL MARGIN OF SAID DISC AND SAID UPSTANDING ANNULAR BEAD WHEREBY SAID PERIPHERAL MARGIN IS MOVABLE AWAY FROM SAID ANNULAR BEAD UNDER THE INFLUENCE OF VAPOR PRESSURE IN SAID CHAMBER TO PERMIT THE ESCAPE OF THE VAPOR PRESSURE TO ATMOSPHERE.