Pipe coupling

Claim 1

IN A PIPE COUPLING ADAPTED TO HAVE ADJACENT ENDS OF ADJOINING LENGTHS OF PIPE INSERTED THEREIN HAVING A TUBULAR MEMBER HAVING OUTWARDLY FLARED ENDS, ANNULAR CLAMP MEMBERS AT OPPOSITE ENDS OF SAID TUBULAR MEMBER EACH OF SAID CLAMP MEMBERS HAVING AN INWARDLY PROJECTING RADIAL FLANGE SPACED AXIALLY FROM THE ENDS OF SAID TUBULAR MEMBER ADJACENT THERETO AND AN AXIALLY EXTENDING FLANGE, SAID AXIALLY EXTENDING FLANGES FACING ONE ANOTHER TO PROVIDE WITH SAID RADIAL FLANGES INTERNAL ANNULAR RECESSES INTO WHICH THE ADJACENT ENDS OF SAID TUBULAR MEMBER EXTEND, SEALING MEANS LOCATED IN SAID ANNULAR RECESSES AND HAVING PORTIONS EXTENDING INTO THE ADJACENT FLARED ENDS OF SAID TUBULAR MEMBER, AND MEANS FOR DRAWING SAID CLAMP MEMBERS TOWARD ONE ANOTHER AND THE ADJACENT ENDS OF SAID TUBULAR MEMBER, A DEVICE FOR TEMPORARILY CLOSING ONE END OF SAID COUPLING COMPRISING: A COVER MEMBER HAVING AN ANNULAR RING PORTION; AN EXTERNAL FLANGE ON ONE END OF SAID ANNULAR RING PORTION ADAPTED TO BE INTERPOSED IN ONE OF THE CLAMP MEMBERS BETWEEN THE FLANGE THEREOF AND THE SEALING MEANS THEREIN; AND A BOWED TRANSVERSE WALL PORTION AT THE END OF SAID ANNULAR RING PORTION OPPOSITE TO SAID EXTERNAL FLANGE SAID TRANSVERSE WALL PORTION BEING BOWED OUTWARDLY IN THE DIRECTION AWAY FROM SAID EXTERNAL FLANGE.