Stop collar

Abstract

Stop collars may be fixedly mounted on a liner or other tubular member. The stop collar comprises a first sleeve and a second sleeve. The sleeves are adapted to extend around the outer circumference of the tubular member and are engaged by threaded connections. The sleeves provide opposing inner thrust surfaces. The collar further comprises a radially expandable gripping member disposed between the opposing thrust surfaces. The sleeves may be drawn together by rotation about the threaded connection to cause the thrust surfaces to bear on the gripping member and expand the gripping member radially inward into frictional engagement with the tubular member.

What is claimed is: 
     
       1. A collar for mounting on a tubular member, said mountable collar comprising:
 (a) a first sleeve and a second sleeve, said sleeves:
 i) extending around the outer circumference of said tubular member; 
 ii) being engaged by threaded connections; and 
 iii) providing opposing inner thrust surfaces; 
 
 (b) a radially expandable gripping member disposed between said opposing thrust surfaces; 
 (c) wherein said sleeves are capable of being drawn together by rotation about said threaded connection to cause said thrust surfaces to bear on said gripping member and expand said gripping member radially inward into frictional engagement with said tubular member. 
 
     
     
       2. The collar of  claim 1 , wherein said gripping member engages said tubular member without penetrating said tubular member. 
     
     
       3. The collar of  claim 1 , wherein said gripping member engages said tubular member without creating electrolytic contact between said collar and tubular member. 
     
     
       4. The collar of  claim 1 , wherein said first sleeve is provided with external threads engaging internal threads on said second sleeve and said gripping member is disposed between the inner end of said first sleeve and an annular shoulder in said second sleeve. 
     
     
       5. The collar of  claim 4 , wherein said gripping member is a compressible band. 
     
     
       6. The collar of  claim 5 , wherein said compressible band is fabricated from an elastomer. 
     
     
       7. The collar of  claim 1 , wherein said second sleeve provides radial support for said gripping member. 
     
     
       8. The collar of  claim 7 , wherein said gripping member is a compressible band. 
     
     
       9. The collar of  claim 8 , wherein said compressible band is fabricated from an elastomer. 
     
     
       10. The collar of  claim 1 , wherein said gripping member is carried in an expanded diameter portion of said second sleeve. 
     
     
       11. The collar of  claim 1 , wherein said collar comprises means for restricting loosening of said threaded engagement between said sleeves. 
     
     
       12. The collar of  claim 11 , wherein said first sleeve comprises a pawl and said second sleeve comprises detents angularly spaced along the inner end of said second sleeve, said pawl selectively engaging said detents to restrict loosening of said threaded engagement between said sleeves. 
     
     
       13. The collar of  claim 11 , wherein a set screw is provided to restrict loosening of said threaded engagement between said sleeves. 
     
     
       14. A tool for mounting on a tubular; said tool comprising a collar of  claim 1 . 
     
     
       15. The tool of  claim 14 , wherein said tool is a stop collar. 
     
     
       16. A centralizing assembly for a tubular member, said assembly comprising:
 (a) a centralizer tool comprising spacing members, said spacing members extending radially outward beyond said tubular member and defining lateral channels; and 
 (b) a stop collar of  claim 1 . 
 
     
     
       17. A tubular assembly, said tubular assembly comprising a tubular and a centralizer assembly of  claim 16 . 
     
     
       18. A collar for mounting on a tubular member, said mountable collar comprising:
 (a) a first member and a second member, said members being:
 i) adapted for lateral displacement relative to each other; and 
 ii) providing opposing inner thrust surfaces; and 
 
 (b) a radially expandable gripping member disposed between said opposing thrust surfaces; 
 (c) wherein said members are capable of being drawn laterally together to cause said thrust surfaces to bear on said gripping member and expand said gripping member radially inward into frictional engagement with said tubular member; and 
 (d) wherein said collar is mounted on said tubular member without penetrating said tubular member. 
 
     
     
       19. The collar of  claim 18 , wherein said gripping member is a compressible band. 
     
     
       20. The collar of  claim 19 , wherein said compressible band is fabricated from an elastomer. 
     
     
       21. A tool for mounting on a tubular; said tool comprising a collar of  claim 18 . 
     
     
       22. The tool of  claim 21 , wherein said tool is a stop collar. 
     
     
       23. A centralizing assembly for a tubular member, said assembly comprising:
 (a) a centralizer tool comprising spacing members, said spacing members extending radially outward beyond said tubular member and defining lateral channels; and 
 (b) a stop collar of  claim 18 . 
 
     
     
       24. A tubular assembly, said tubular assembly comprising a tubular and a centralizer assembly of  claim 23 .