US Patent 10288200 Coupling with tongue and groove

A pipe joint assembly including a first pipe element, a second pipe element, a pair of segments, each segment defining a first end and a second end, each first end comprising a tongue and each second end comprising a groove, each groove defining a groove shoulder surface, the tongue of the one segment defining a tongue outer surface, the tongue outer surface of the tongue of the one segment angled at a non-zero angle relative to the groove shoulder surface in an assembled and untightened position, the tongue outer surface of the tongue positioned parallel and flush to the groove shoulder surface of the groove of the second segment in an assembled and tightened condition; and a pair of fasteners configured to deflect each segment around the first pipe element and the second pipe element in the assembled and tightened condition.