Safety means for glad hand couplings

Claim 1

THE COMBINATION WITH A PAIR OF GLAD HAND COUPLINGS EACH INCLUDING A BODY HAVING FRONT AND REAR ENDS AND A LATERAL OPENING EXTENDING THROUGH ONE SIDE THEREOF, A LOCK ARM CONNECTED TO THE REAR END OF SAID BODY AND SPACED ABOVE SAID ONE SIDE, AND A FORWARD EXTENSION INCLUDING A LOCK RIB ON THE FRONT END OF SAID BODY, SAFETY MEANS FOR PREVENTING THE MISMATCHING OF SAID COUPLINGS COMPRISING A VERTICAL LUG FIXED TO THE BODY OF ONE OF SAID COUPLINGS ON THE SAID ONE SIDE THEREOF, SAID LUG BEING CIRCUMFERENTIALLY POSITIONED INTERMEDIATE THE FORWARD EXTENSION AND THE ENTRANCE TO SAID LOCK ARM AND INCLUDING A VERTICAL RADIAL WALL FACING IN THE DIRECTION OF SAID EXTENSION, A SECOND LUG ON THE EXTENSION OF THE OTHER COUPLING ON THE SAID ONE SIDE THEREOF, SAID SECOND LUG BEING CIRCUMFERENTIALLY SPACED AWAY FROM THE ENTERING SIDE OF SAID EXTENSION AND HAVING A RADIAL VERTICAL WALL INTERMEDIATE THE SIDES OF SAID EXTENSION AND FACING THE ENTERING SIDE THEREOF, THE RESPECTIVE VERTICAL WALLS OF SAID LUGS HAVING DIMENSIONS WHEREIN SAID LUGS ENGAGE EACH OTHER TO PREVENT POSITIVELY CONNECTED OF SAID COUPLINGS UPON MOVEMENT THEREOF IN A COUPLING DIRECTION, SAID LUGS BEING CONSTRUCTED AND ARRANGED TO NOT INTERFER WITH THE CONNECTION OF A COUPLING NOT EQUIPPED WITH A LUG ENGAGEABLE WITH ONE OR THE OTHER OF THE FIRTST MENTIONED LUGS.