Tube coupling

Claim 1

A TUBE COUPLING STRUCTURE INCLUDING: A BODY RECEIVING A TUBE IN ITS AXIAL BORE WITH SUBSTANTIALLY THE EXTERNAL DIAMETER OF THE TUBE IT RECEIVES AND HAVING AN INTERNAL ABUTTING SURFACE EXTENDING AWAY FROM THE BORE OF THE COUPLING, THE ABUTTING SURFACE COMPRISING, A LARGE FLARED SURFACE AT THE ENTRANCE TO THE BODY BORE, AND A SHOULDER EXTENDED FROM THE INTERNAL END OF THE FLARED SURFACE TO THE BORE WHICH HAS A DIAMETER SUBSTANTIALLY THE SAME AS THE EXTERNAL DIAMETER OF THE TUBE; A COLLET RECEIVING THE TUBE IN ITS AXIAL BORE AND HAVING, A FORWARD ABUTTING SURFACE MATING WITH THE BODY ABUTTING SURFACE TO POSITIVELY LIMIT THE MOVEMENT OF THE COLLET INTO THE BODY BORE, THE FORWARD ABUTTING SURFACE COMPRISING, A SHARP LEADING EDGE PORTION SIZED TO BE DIRECTED BY THE BODY SHOULDER INTO THE TUBE SURFACE TO DEVELOP AN ABUTMENT OF THE TUBE MATERIAL, AND A SURFACE EXTENDING BACK FROM THE SHARP LEADING EDGE WHICH IS SHAPED TO MATCH THE FLARED SURFACE OF THE BODY AND DEVELOP SUFFICIENT FRICTION BETWEEN THE TWO SURFACES TO PREVENT RELATIVE ROTATION BETWEEN THE COLLET AND THE BODY TO KEEP TORQUE APPLIED TO THE COLLET FROM BEING TRANSMITTED TO THE TUBE AND POSITIVELY LIMIT THE DIRECTION OF THE SHARP EDGE INTO THE TUBE SURFACE, AN EXTERNAL GROOVE FORMED INTERMEDIATE THE COLLET ENDS, AND A SHARP-EDGED STEP ON THE INTERNAL SURFACE OF THE COLLET BORE AND OPPOSITE THE COLLET GROOVE; AND A NUT THREADEDLY ENGAGING THE BODY TO CAPTURE THE COLLET BETWEEN THE BODY AND NUT AND COLLAPSE THE COLLET GROOVE AND THEREBY MOVE THE COLLET WEB INWARDLY TO DIRECT THE SHARP-EDGED STEP INTO THE TUBE SURFACE AND DEVELOP AN ABUTMENT OF THE TUBE MATERIAL AGAINST WHICH THE STEP RETAINS THE TUBE IN THE COUPLING AND SEALS TO THE TUBE AND DIRECT THE SHARP LEADING EDGE PORTION OF THE COLLET WITH THE BODY SURFACES AND BRING THE MATING SURFACES OF THE BODY AND COLLET TOGETHER.