A flexible gimbal joint for pipes including an internal flexible seal interconnecting the pipes and an external gimbal ring which also provides secondary sealing. The joint includes spherical portions with mating sinusoidal free edges, the external ring and four trunnion pins, each pin coupled to the...http://www.google.de/patents/US4643463?utm_source=gb-gplus-sharePatent US4643463 - Gimbal joint for piping systems
