US Patent 10024467 Fittings having arcuate stiffness ribs

Fittings, including elbow fittings and Tee fittings have bodies that surround a central space and define openings to receive pipe elements. Ribs surround the openings, and gaps are positioned between the ribs to permit deformation of the body when ends of the body in facing relation are brought together. The body may be formed of two housings or unitary in construction. The ribs may be grooved to accommodate toothed retainer rings providing mechanical engagement with pipe elements. The ribs have surfaces with radii of curvature that, when the ribs are undeformed, are substantially equal to the radii of curvature of the pipe elements they engage.