Pipe coupling having a band clamp and resilient sleeve

Claim 1

IN A COUPLING FOR JOINING TWO PIECES OF PIPE IN SEALING RELATION AND WHOSE END REGIONS HAVE THEIR EXTERIOR SURFACES TAPERED OUTWARDLY IN THE DIRECTION OF THEIR ENDS, A TUBULAR GASKET OF RESILIENT MATERIAL HAVING A BORE WALL CONTOUR MATCHING THE CONTOURS OF SUCH EXTERIOR SURFACES AND HAVING A RIB FOR PROJECTION BETWEEN THE ADJOINING ENDS OF SUCH PIECES OF PIPE, SAID GASKET HAVING AN OUTER CONFIGURATION EMBODYING TWO ANNULAR END SECTIONS AND A MIDDLE SECTION OF TRIANGULAR CROSS SECTIONAL CONFIGURATION WITH THEIR BASE AREAS CONNECTED TO ONE ANOTHER BY SECTIONS OF SMALL CROSS SECTIONAL AREA RELATIVE TO THE CROSS SECTIONAL AREAS OF TRIANGULAR CONFIGURATION, AND A CLAMPING BAND CIRCUMFERENTIALLY SURROUNDING SAID GASKET HAVING AXIALLY TAPERED INNER END WALL PORTIONS THAT LOCALLY APPLY FORCES TO THE OUTER END REGIONS OF SUCH END SECTIONS IN DIRECTIONS TO COMPRESS SUCH RIB BETWEEN THE PIPE ENDS, AND HAVING A WALL REGION THAT APPLIES FORCES TO THE MIDDLE SECTION TOWARD THE AXIAL CENTER OF THE COUPLING TO COMPRESS SUCH MIDDLE SECTION ABOUT THE SURROUNDED SURFACES OF THE PIPE ENDS.