A coupler for securing at least one pipe having a planar end. A hollow rigid coupler shell and a rigid tube stiffener are secured in the shell by a hub member, the stiffener having an external diameter less than an internal diameter of the pipe. The hub member has an internal diameter less than an external...http://www.google.com.au/patents/US5524940?utm_source=gb-gplus-sharePatent US5524940 - Pipe coupler device
