US Patent 7996981 Method of joining pipes in end to end relation

A method for connecting pipe elements together end to end. The method includes providing a coupling having a plurality of segments with at least one camming surface, the segments being joined end to end by a plurality of adjustably tightenable fasteners, positioning a first and a second of the pipe elements in end to end relation, positioning the segments surrounding the ends of the pipe elements, engaging the camming surfaces on the segments with grooves on the pipe elements and tightening the fasteners so as to draw the segments toward one another. The camming surfaces slide into the grooves and move the first and second pipe elements away from one another.