US Patent 7219934 Pipe coupling

A pipe coupling for coupling the ends of pipe sections together end to end, wherein the coupling includes a barrel member, at least one coupling member, at least one elastomeric sealing ring, a tangentially extending bolt and interacting members. The barrel member surrounds the ends of the pipe sections and the coupling member engages an end of the barrel member. The sealing ring is disposed between an end of the barrel member and the coupling member, and expands radially outward and inward to seal within the end of the barrel member and around a circumference of one of the pipe sections. The bolt couples the coupling member to the barrel member. The interaction members interact and progressively twist the coupling member along the barrel member to force the sealing ring into sealing engagement within the barrel member and around the circumference of the pipe sections.