Flareless tube coupling nut and ferrule assembly

Claim 1

A TUBE COUPLING ASSEMBLY COMPRISING A BODY MEMBER, NUT MEANS IN THREADED ENGAGEMENT WITH SAID BODY MEMBER, SAID NUT MEANS AND BODY MEMBER DEFINING THEREBETWEEN A TUBE- END RECEIVING CAVITY INCLUDING AN ANNULAR SPACE AROUND A TUBE IN SUCH CAVITY, A METAL SLEEVE SURROUNDING SAID TUBE WITHIN SUCH ANNULAR SPACE, SAID BODY MEMBER HAVING A TAPERED WALL PORTION, SAID SLEEVE HAVING A RELATIVELY THIN FORWARD END PORTION AND A RADIALLY THICKENDED INTERMEDIATE PORTION, SAID NUT MEANS HAVING A RADIALLY INWARDLY EXTENDING SHOULDER INITIALLY IN CONTACT WITH ONLY THE RADIAL OUTERMOST PART OF SAID THICKENED INTERMEDIATE PORTION THROUGH WHICH AXIAL COMPRESSION FORCE IS IMPOSED DURING TIGHTENING OF SAID NUT MEANS TO FORCE SAID FORWARD END PORTION INTO CONTACT WITH SAID TAPERED WALL PORTION FOR CONTRACTING SAID FORWARD END PORTION INTO FLUID-TIGHT GRIPPING ENGAGEMENT WITH SAID TUBE AT A ZONE AXIALLY SPACED FROM SAID INTERMEDIATE THICKENED PORTION DURING WHICH THERE IS SUBSTANTIALLY NO DEFORMATION OF SAID THICKENED INTERMEDIATE PORTION, SAID SLEEVE ALSO HAVING AN EXTENSION PROJECTING AXIALLY FROM SAID THICKENED INTERMEDIATE PORTION OUTWARDLY THROUGH A BORE IN SAID NUT MEANS, SAID EXTENSION HAVING A RADIAL ENLARGEMENT AXIALLY OUTWARDLY OF SAID NUT MEANS TO FORM A RETAINING SHOULDER FOR HOLDING SAID NUT MEANS AND SLEEVE TOGETHER, SAID NUT MEANS THROUGH CONTINUED TIGHTENING BEING OPERATIVE ONLY AFTER SUCH FLUID-TIGHT GRIPPING ENGAGEMENT HAS BEEN ESTABLISHED TO EFFECT DEFORMATION OF SAID THICKENED INTERMEDIATE PORTION TO CAUSE RADIAL CONTRACTION OF SAID SLEEVE IN THE REGION OF SAID THICKENED INTERMEDIATE PORTION INTO VIBRATION DAMPING ENGAGEMENT WITH SAID TUBE, SAID NUT MEANS ADVANCING AXIALLY WITH RESPECT TO SAID RETAINING SHOULDER ONLY DURING DEFORMATION OF SAID THICKENED INTERMEDIATE PORTION AS AFORESAID TO PROVIDE A VISUAL INDICATION BOTH THAT SUCH FLUID-TIGHT GRIPPING ENGAGEMENT HAS BEEN ESTABLISHED AND OF THE EXTENT OF FLUID DAMPING ENGAGEMENT OF SAID SLEEVE WITH SAID TUBE.