US Patent 8424918 Deformable mechanical pipe coupling with shoulder pipe elements

A mechanical pipe coupling formed of segments attached end to end surrounding a central space is used to connect pipe elements having a raised circumferential shoulder in end to end relationship. The segments have arcuate surfaces and arcuate landings which subtend an angle less than 180° and which have a radius of curvature greater than the radius of curvature of outer surfaces of the pipe elements on the raised circumferential shoulder. The segments are maintained in spaced relation allowing the pipe elements to be inserted into the central space without disassembling the pipe coupling. Connection members attaching the segments to one another are tightened to engage the arcuate surfaces or the arcuate landings with outer surfaces of the pipe elements to effect the connection.