Breakaway pipe coupling

Claim 1

A breakaway pipe coupling for coupling a pipeline together comprising: a first longitudinally extending open-ended generally tubular coupling member having a bearing ring thereon; a second longitudinally extending open-ended generally tubular coupling member telescopingly fitting over one of the ends of said first coupling member and including sealing means thereon for maintaining said coupling members in fluid-tight relationship; flange means surrounding said first and second coupling means for holding said first and second coupling members in fixed relationship; said flange means including an upper flange portion encircling said second coupling member and secured thereto and a mating lower flange portion encircling said first coupling member; said lower flange portion comprising a pair of split ring portions having interlocking engagement means disposed on the abutting end portions of said pair of split rings, said engagement means preventing lateral movement of said split rings while permitting axial disengagement of said split rings; said pair of split rings in addition having a bearing surface formed thereon and disposed to engage the bearing ring on said first coupling means to prevent axial movement of said first coupling means in at least one direction; one of said ring members in addition having a greater axial thickness than the other of said ring members, said difference in thickness being sufficient to permit said engagement means to be disengaged when said one ring member contacts an axial stop; and frangible securing means connected to each of said flange portions for securing said flange portions together until the frangible limit of said securing means is reached whereby said engagement means on said ring members may be disengaged and said ring members separate and drop off of said first coupling member.