Claims
- 1. A phase controlled sequential gripping tube fitting for gripping a tube therein, the fitting comprising:
a rear ferrule shaped to receive said tube therein, the rear ferrule having a nose portion and a central body; and a front ferrule having an axially-extending rear portion radially outwardly spaced from said rear ferrule; whereby when said rear ferrule is urged axially in a first direction said rear ferrule grips said tube, and whereby said rear portion of said front ferrule reduces buckling of said rear ferrule.
- 2. The phase controlled sequential gripping tube fitting of claim 1 wherein said central body does not contact said rear portion of said front ferrule during make-up of said fitting except when said rear ferrule buckles.
- 3. The phase controlled sequential gripping tube fitting of claim 1 wherein said rear portion of said front ferrule extends along a significant length of said central body.
- 4. The phase controlled sequential gripping tube fitting of claim 1 wherein said front ferrule includes a tapered nose shaped to engage a camming mouth of a main body, and wherein said front ferrule further includes a force receiving surface located between said rear portion and said tapered nose.
- 5. The phase controlled sequential gripping tube fitting of claim 4 wherein said rear ferrule has a rear force receiving surface and wherein said nose portion is shaped to extend into said force receiving surface of said front ferrule, and wherein said central body is located between said rear force receiving surface and said nose portion.
- 6. The phase controlled sequential gripping tube fitting of claim 1 wherein said ferrule is unitary.
- 7. The phase controlled sequential gripping tube fitting of claim 1 wherein said front ferrule has an outer diameter greater than the outer diameter of said rear ferrule.
- 8. A phase controlled sequential gripping tube fitting for gripping a tube therein, the fitting comprising:
a rear ferrule shaped to receive said tube therein, the rear ferrule having a central body having a thickness; and a front ferrule having an axially-extending rear portion having a thickness greater than the thickness of said central body, said axially-extending rear portion being located radially outwardly of said central body; whereby when said rear ferrule is urged axially in a first direction said rear ferrule grips said tube, and whereby said rear portion of said front ferrule reduces buckling of said rear ferrule.
- 9. The phase controlled sequential gripping tube fitting of claim 8 wherein said thickness of said central body is less than about two-thirds of said thickness of said rear portion of said front ferrule.
- 10. The phase controlled sequential gripping tube fitting of claim 8 wherein said rear portion extends over a substantial length of said rear ferrule.
- 11. The phase controlled sequential gripping tube fitting of claim 8 wherein said rear port ion is radially spaced from said central body.
- 12. A phase controlled sequential gripping tube fitting for gripping a tube therein, the fitting comprising:
a rear ferrule shaped to receive said tube therein; and a front ferrule having an axially-extending rear portion extending over a substantial length of said rear ferrule and being located radially outwardly of said rear ferrule; whereby when said rear ferrule is urged axially in a first direction said rear ferrule grips said tube, and whereby said rear portion of said front ferrule reduces buckling of said rear ferrule.
- 13. The phase controlled sequential gripping tube of claim 12 wherein said axially-extending portion extends over at least about one fourth of the length of said rear ferrule.
- 14. The phase controlled sequential gripping tube fitting of claim 12 wherein rear ferrule has a central body, and wherein said axially-extending portion extends over less than about half of said central body.
- 15. A phase controlled sequential gripping tube fitting for gripping a tube therein, the fitting comprising:
a rear ferrule shaped to receive said tube therein, said rear ferrule having a central body; a front ferrule having an axially-extending rear portion having a rear face, said axially-extending portion being located radially outwardly of said rear ferrule; and a gap adjacent said rear face, said gap providing a space into which said front ferrule may be received as said front ferrule and said rear ferrule plastically deform with repeated make-ups of the fitting; whereby when said rear ferrule is urged axially in a first direction said rear ferrule grips said tube and said rear portion of said front ferrule reduces buckling of said rear ferrule.
- 16. The phase controlled sequential gripping tube fitting of claim 15 wherein said gap extends axially a significant distance relative said central body.
- 17. The phase controlled sequential gripping tube fitting of claim 16 wherein said gap extends axially greater than about one-third the length of said central body.
- 18. The phase controlled sequential gripping tube fitting of claim 17 wherein said gap is located between said rear ferrule and a coupling element for contacting said rear ferrule and for urging said rear ferrule in said first direction.
- 19. A phase controlled sequential gripping tube fitting comprising:
a front ferrule having an axially-extending rear portion having a rear face, a tapered nose shaped to engage a camming mouth of a main body, and a force receiving surface located between said rear portion and said tapered nose; and a rear ferrule having a rear force receiving surface, a tapered nose shaped to extend into said force receiving surface of said front ferrule, and a central body portion located between said rear force receiving surface and said tapered nose, said central body being located radially inward of and radially spaced from said rear portion of said front ferrule; whereby when said rear force receiving surface is urged axially inwardly said nose of said rear ferrule is driven against said force receiving surface of front ferrule to thereby urge said rear ferrule nose radially inwardly, and whereby said rear portion of said front ferrule reduces buckling of said rear ferrule.
- 20. The phase controlled sequential gripping tube fitting of claim 19 further comprising a coupling element having a force applying surface for contacting said rear force receiving surface and for urging said rear force receiving surface axially inwardly.
- 21. The phase controlled sequential gripping tube fitting of claim 20 wherein said coupling element is located so as to impede radially outward movement of said front ferrule.
- 22. In a phase controlled sequential gripping tube fitting including a main body having a cylindrical tube end receiving opening with a tapered camming mouth forming the entry to said opening, a front ferrule having a tapered forward nose surface in engagement in the camming mouth and a rear surface with a conically tapered recess extending forwardly toward the nose surface, a rear ferrule having a conically tapered nose extending into the conically tapered recess of the front ferrule and a rear force receiving surface, a coupling nut threadedly connected to the main body and having a force applying face engaged with the rear force receiving surface of the rear ferrule to drive the rear ferrule axially forward into the conically tapered rear surface of the front ferrule and produce radially inward movement of the nose portion of said rear ferrule, the improvement comprising:
an arrangement to control outward buckling of the rear ferrule and including a cylindrical central body on the rear ferrule, the central body located between the nose portion and the rear force receiving surface, and a cylindrical flange extending axially rearwardly from the front ferrule at a location radially outwardly of the rear recess, the flange having a cylindrical interior surface that closely surrounds the cylindrical central body of the rear ferrule and an axial end face that is facing toward and axially spaced from the force applying face of the coupling nut, wherein the axial length of the flange is no more than about one-half the axial length of the cylindrical central body of the rear ferrule.
- 23. A method for gripping a tube comprising the steps of:
selecting a rear ferrule shaped to receive said tube therein, the rear ferrule having a nose portion and a central body; selecting a front ferrule having an axially-extending rear portion; mounting said front ferrule and said rear ferrule on said tube such that said axially-extending portion is radially outwardly spaced from said rear ferrule; and urging said rear ferrule in a first axial direction such that said rear ferrule grips said tube, and whereby said rear portion of said front ferrule reduces buckling of said rear ferrule.
- 24. The method of claim 23 wherein said central body does not contact said rear portion of said front ferrule during said urging step except when said rear ferrule buckles.
- 25. The method of claim 23 wherein said rear ferrule is urged in said first axial direction by a coupling nut.
- 26. The method of claim 23 wherein said rear portion of said front ferrule extends along a significant length of said central body.
- 27. The method of claim 23 wherein said front ferrule includes a tapered nose shaped to engage a camming mouth of a main body and wherein said front ferrule further includes a force receiving surface located between said rear portion and said tapered nose.
- 28. The method of claim 27 wherein said rear ferrule has a rear force receiving surface, a tapered nose shaped to extend into said force receiving surface of said front ferrule, and wherein said central body is located between said rear force receiving surface and said tapered nose.
- 29. A method for gripping a tube comprising the steps of:
selecting a rear ferrule shaped to receive said tube therein, the rear ferrule having a central body having a thickness; selecting a front ferrule having an axially-extending rear portion having a thickness greater than the thickness of said central body; mounting said front ferrule and said rear ferrule on said tube such that said axially-extending rear portion is located radially outwardly of said central body; and urging said rear ferrule in a first axial direction such that said rear ferrule grips said tube, and whereby said rear portion of said front ferrule reduces buckling of said rear ferrule.
Parent Case Info
[0001] This application is a continuation-in-part of U.S. Ser. No. 08/787,967, filed Jan. 23, 1997.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
08787967 |
Jan 1997 |
US |
Child |
09137590 |
Aug 1998 |
US |