Pipe coupling

Claim 1

IN A TUBE COUPLING INCLUDING A METAL TUBE, A BODY MEMBER HAVING A BORE ADAPTED TO BE COUPLED IN ALIGNMENT WITH THE END OF THE TUBE, A COUPLING MEMBER SURROUNDING THE TUBE AND ADAPTED TO BE DRAWN UP TOWARD THE BODY, AND A METAL SLEEVE BETWEEN AND IN ENGAGEMENT WITH THE BODY AND THE COUPLING MEMBER AND HAVING A CIRCUMFERENTIALLY CONTINUOUS ANNULAR PORTION HAVING AN INNER PERIPHERY SURROUNDING THE TUBE, SAID COUPLING INCLUDING MEANS ACTING TO FORCE SAID ANNULAR PORTION RADIALLY INTO THE TUBE AND SIMULTANEOUSLY MOVE THE SAME FORWARDLY TOWARD THE BODY MEMBER WHEN THE COUPLING MEMBER IS DRAWN UP TOWARD THE BODY MEMBER, THE COUPLING HAVING ABUTMENT MEANS LIMITING FORWARD MOVEMENT OF THE TUBE DURING SUCH MOVEMENT OF SAID ANNULAR PORTION; THE IMPROVEMENT COMPRISING TUBE CUTTING EDGES INCLUDING FORWARDLY FACING TEETH AROUND SAID ANNULAR PORTION, SAID TEETH HAVING SPACED CREST PORTIONS AND FLANK PORTIONS DIVERGING REARWARDLY FROM EACH CREST PORTION, EACH JOINED TO THE ADJACENT FLANK PORTION BY A ROOT PORTION, SAID CREST PORTIONS, FLANK PORTIONS, AND ROOT PORTIONS INTERSECTING THE INNER PERIPHERY OF SAID ANNULAR PORTION IN SHARP CUTTING EDGES CONTINOULSY JOINED TOGETHER ABOUT THE ENTIRE INNER PERIPHERY OF SAID ANNULAR PORTION, WHEREBY SAID TUBE CUTTING EDGES CUT INTO THE SURFACE OF SAID TUBE AND SHEAR UP AN UNINTERRUPTED RIDGE OF METAL PROJECTING RADIALLY AROUND THE ENTIRE PERIPHERY OF SAID TUBE, SAID RIDGE OF METAL HAVING SERRATIONS FILLING THE SPACES BETWEEN SAID TEETH AND FORMING A FLUID SEAL AND HOLDING SAID TUBE AGAINST AXIAL SEPARATION FROM THE BODY MEMBER.