Coupling Having Angularly Oriented Key Surfaces

A coupling for joining 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;
• each of said segments having a pair of arcuate keys extending along each of said segments and projecting radially inwardly toward said central space, said keys of each said pair being in spaced apart relation to one another, each of said keys comprising two oppositely disposed side surfaces and a first mid surface, each of said first mid surfaces being angularly oriented with respect to an axis oriented perpendicularly to a plane containing said segments, portions of said first mid surfaces being engageable with outer surfaces of said pipe elements when said pipe elements are positioned within said central space.

A method of joining pipe elements in end to end relationship, said method comprising:

• providing a coupling formed of a plurality of segments joined end to end by a plurality of adjustably tightenable fasteners, said segments surrounding a central space, 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;
• inserting said pipe elements into said central space from opposite sides of said coupling;
• tightening said fasteners so as to draw said segments toward one another and thereby engaging a portion of said first mid surface with an outer surface of at least one of said pipe elements.

In combination, a pair of pipe elements and a coupling for joining the pipe elements together in end to end relation, each of said pipe elements having a circumferential groove located adjacent to each end, each said groove comprising a pair of oppositely disposed sides and a floor;

• and wherein said coupling comprises:
• a plurality of segments attached to one another end to end surrounding a central space;
• 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 said floor of said groove, a portion of said first mid surface being engageable with said floor when said pipe elements are positioned within said central space.