Patent ID: 8267432

Claim:
In combination, pipe elements and a coupling for joining said pipe elements together in end to end relation, said coupling comprising: a plurality of segments attached to one another end to end surrounding a central space; connection members positioned at opposite ends of said segments for adjustably connecting one coupling segment to another; at least one of said segments including an arcuate key extending along said segment and projecting inwardly toward said central space, said key comprising two oppositely disposed side surfaces and a first mid surface positioned therebetween, said first mid surface facing radially inwardly toward said central space, said first mid surface being angularly oriented with respect to an axis oriented perpendicularly to a plane containing said segments, a portion of said first mid surface being engageable with an outer surface of one of said pipe elements when said pipe elements are positioned within said central space, said connection members being adjustably tightenable for drawing said first mid surface into engagement with said outer surface of said one pipe element; and wherein said first mid surface subtends an angle of less than 180° and has a minimum radius of curvature greater than the radius of curvature of said outer surface of said pipe element, at least said one segment being deformable upon adjustable tightening of said connection members so as to substantially conform the curvature of a portion of said first mid surface to the outer surface of said pipe element.