Tubing fitting

Claim 2

An improved pre-assembled sleeve type conduit coupling of the type wherein a conduit is coupled merely by stabbing it into the open end of the coupling sleeve bore, comprising: a grab ring formed of thin springy metal having a smooth outer edge and a conical flange converging radially inwardly toward the coupling bore and axially inwardly away from the open end of the coupling bore, the innermost edge of the flange defining a conduit receiving bore which is normally smaller than the outer diameter of the conduit but which resiliently yields upon insertion Of the conduit and which is provided with non-helical conduit gripping means for engaging and gripping the conduit upon attempted withdrawl of the conduit from the coupling; said grab ring and conduit being freely jointly rotatable relative to the coupling; a resilient sealing ring having a bore for receiving the conduit and having a first sealing surface for yieldably engaging and sealing against the outer periphery of the conduit at a point axially outwardly of the conduit gripping means toward said open end of said coupling sleeve and a second sealing surface for yieldably engaging and sealing against the coupling bore; and an annular cap pre-assembled to the coupling and having a shoulder for limiting axially outward movement of said sealing ring toward the open end of the coupling bore; said grab ring and said sealing ring having abutting surfaces which cooperate upon attempted withdrawl of the conduit and during elevated fluid pressure within the coupling for axially compressing said sealing ring between said grab ring and said cap thereby increasing the radial sealing forces at said first and second sealing surfaces.

Claim 3

The coupling of claim 1 wherein the sleeve is provided with a first radially extending internal shoulder which acts as a positive stop for limiting axial insertion of the conduit and a second internal shoulder which acts as a positive stop for limiting axial insertion of said grab ring; the sleeve and said cap having cooperating surfaces which limit the axially inward positioning of said cap relative to the sleeve, said cap being permanently and non-adjustably pre-assembled to the sleeve to establish a predetermined and fixed axial distance between said cap shoulder and said second sleeve shoulder for limiting and controlling the space available for axial movement of said sealing ring.

Claim 4

The coupling of claim 1 wherein said sleeve is provided with a plurality of axial ribs, each rib having a first radially extending internal shoulder which acts as a positive stop to limit axial insertion of the conduit, and a second radially extending internal shoulder which acts as a positive stop to limit axial insertion of said grab ring; said second internal shoulder being axially outwardly of said first internal shoulder.

Claim 5

The coupling of claim 1 wherein said grab ring and said sealing ring are discrete elements separately inserted into said pre-assembled coupling.

Claim 6

An improved pre-assembled conduit coupling of the type wherein a conduit is coupled merely by stabbing it into the open end of a coupling sleeve, comprising: a grab ring having a smooth outer edge and a conical flange converging radially inwardly towards the coupling bore and axially inwardly away from the open end of the coupling bore, the innermost edge of said conical flange having non-helical conduit gripping means for engaging and for gripping said conduit upon attempted withdrawal of the conduit from the coupling; said grab ring and the conduit being freely jointly rotatable relative to the coupling sleeve; a resilient sealing ring having a first sealing surface for yieldably engaging and for sealing against the outer periphery of the conduit at a point axially outwardly of the conduit gripping means toward said open end of said coupling sleeve and a second sealing surface for yieldably engaging and sealing against the interior of the coupling sleeve; an annular cap having a shoulder for limiting axially outward movement of said sealing ring toward the open end of the coupling sleeve; said grab ring and said sealing ring having abutting surfaces which cooperate upon attempted withdrawal of the conduit and during elevated fluid pressure within the coupling for axially compressing said sealing ring between said grab ring and said cap for increasing the radial sealing forces at said first and second sealing surfaces; said coupling sleeve being provided with a first radially extending internal shoulder for positively limitinG axial insertion of the conduit and a second radially extending internal shoulder which extends inwardly less than said first radially extending internal shoulder, said second radially extending internal shoulder for limiting axial insertion of said grab ring; said sleeve and said cap having cooperating axial edges for limiting the axially inward position of the said cap relative to said sleeve, the cap being permanently and non adjustably assembled to the sleeve prior to the insertion of said conduit to establish a predetermined and fixed axial distance between said cap shoulder and said second radially extending inward free shoulder for limiting and controlling the space for axial movement of said sealing ring; and said fixed axial distance between said cap shoulder and said second radially extending internal shoulder being greater than the normal uncompressed combined axial length of said grab ring and said sealing ring for providing limited axial movement of the conduit relative to the coupling without axially compressing said sealing ring.

Claim 7

An improved pre-assembled conduit coupling of the type wherein a conduit is coupled merely by stabbing it into the open end of a coupling sleeve, comprising: a grab ring having a smooth outer edge and a conical flange converging radially inwardly towards the coupling bore and axially inwardly away from the open end of the coupling bore, the innermost edge of said conical flange having non-helical conduit gripping means for engaging and for gripping said conduit upon attempted withdrawal of the conduit from the coupling; said grab ring and the conduit being freely jointly rotatable relative to the coupling sleeve; a resilient sealing ring having a first sealing surface for yieldably engaging and for sealing against the outer periphery of the conduit at a point axially outwardly of the conduit gripping means toward said open end of said coupling sleeve and a second sealing surface for yieldably engaging and sealing against the interior of the coupling sleeve; an annular cap having a shoulder for limiting axially outward movement of said sealing ring toward the open end of the coupling sleeve; said grab ring and said sealing ring having abutting surfaces which cooperate upon attempted withdrawal of the conduit and during elevated fluid pressure within the coupling for axially compressing said sealing ring between said grab ring and said cap for increasing the radial sealing forces at said first and second sealing surfaces; said coupling sleeve being provided with a first radially extending internal shoulder for positively limitinG axial insertion of the conduit and a second radially extending internal shoulder which extends inwardly less than said first radially extending internal shoulder, said second radially extending internal shoulder for limiting axial insertion of said grab ring; said sleeve and said cap having cooperating axial edges for limiting the axially inward position of the said cap relative to said sleeve, the cap being permanently and non adjustably assembled to the sleeve prior to the insertion of said conduit to establish a predetermined and fixed axial distance between said cap shoulder and said second radially extending inward free shoulder for limiting and controlling the space for axial movement of said sealing ring; and said fixed axial distance between said cap shoulder and said second radially extending internal shoulder being greater than the normal uncompressed combined axial length of said grab ring and said sealing ring for providing limited axial movement of the conduit relative to the coupling without axially compressing said sealing ring.