Downhole tool piston assembly

Abstract

A piston assembly may comprise a housing with a wall, and at least one chamber formed in the wall. A piston may be disposed within the chamber and at least one passageway may pass through the piston. At least one pin may be disposed within the passageway and attached to the chamber, and the piston may be free to translate relative to the pin.

What is claimed is: 
     
       1. A piston assembly, comprising:
 a housing comprising a wall; 
 at least one chamber formed in the wall; 
 a piston disposed within the chamber; wherein the piston comprises, the piston including a working surface adjacent the wall, a base surface opposite the working surface, and an intermediate surface joining the working surface and the base surface, the piston including a first passageway intersecting the intermediate surface, the intermediate surface enclosing a top edge and a bottom edge of the first passageway; 
 at least one passageway through the piston; 
 wherein the base surface comprises an opening to the a second passageway; and 
 at least onea pin disposed within the passageway and attached to the chamber; and whereinpassing into the first passageway, the entire piston isbeing free to translatemove relative to the pin. 
 
     
     
       2. The assembly of  claim 1 , wherein the chamber is in fluid communication with a fluid source. 
     
     
       3. The assembly of  claim 1 , wherein the housing is selected from a group consisting of drill bits, calipers, reamers, shock absorbers, jars, clamps, tractors, stabilizers, fishing tools, and combinations thereof. 
     
     
       4. The assembly of  claim 3 , wherein the housing consists of a drill bit and the wall and the chamber are disposed on a gauge surface of the drill bit. 
     
     
       5. The assembly of  claim 1 , wherein the housing comprises a tube and the wall is disposed within the tube. 
     
     
       6. The assembly of  claim 1 , wherein the housing comprises a tube and the wall is disposed on a surface of the tube. 
     
     
       7. The assembly of  claim 1 , wherein the chamber comprises a cross section selected from the group consisting of a circle, oval, polygon, star, rectangle with circular ends, and annulus. 
     
     
       8. The assembly of  claim 1 , wherein the piston comprises a cross sectional shape similar to the chamber. 
     
     
       9. The assembly of  claim 1 , wherein the chamber comprises openings to allow passage of the pin and fluid communication with the chamber. 
     
     
       10. The assembly of  claim 1 , wherein the chamber is lined with a sleeve and the sleeve comprises openings to allow passage of the at least one pin. 
     
     
       11. The assembly of  claim 1 , wherein the first passageway intersects at least one of the intermediate surface and the base surface. 
     
     
       12. The assembly of  claim 1 , wherein the working surface comprises wear resistant elements disposed thereon. 
     
     
       13. The assembly of  claim 1 , wherein the base surface is nonplaner and comprises a topography selected from the group consisting of grooves, dimples, flutes, fins, troughs, and protrusions. 
     
     
       14. The assembly of  claim 1 , wherein the pin comprises a cross section selected from the group consisting of a circle, oval, polygon, star, rectangle with circular ends, and annulus. 
     
     
       15. The assembly of  claim 1 , wherein the pin comprises an aperture there through. 
     
     
       16. The assembly of  claim 1 , wherein the pin comprises a sleeve surrounding at least a portion of the pin. 
     
     
       17. The assembly of  claim 1 , wherein the first passageway comprises a cross-sectional area greater than a cross-sectional area of the pin. 
     
     
       18. The assembly of claim  1  10, further comprising a seal disposed between the chamber and the piston, the piston and the sleeve, or the chamber and the sleeve. 
     
     
       19. The assembly of claim 1, the first passageway traversing the piston. 
     
     
       20. The assembly of claim 19, the pin passing through the piston. 
     
     
       21. The assembly of claim 19, the first passageway including a top edge and a bottom edge, the piston being free to move relative to the pin to until pin contacts the top edge or the bottom edge. 
     
     
       22. The assembly of claim 1, the pin including a plurality of pins and the first passageway including a plurality of passageways, the plurality of pins passing into the plurality of passageways in the piston. 
     
     
       23. The assembly of claim 22, the plurality of pins being disposed within the piston at different angles around the piston. 
     
     
       24. The assembly of claim 22, each pin of the plurality of pins having an inner side and an outer side, the inner side passing through the piston and the outer side being connected to the wall. 
     
     
       25. The assembly of claim 22, at least two pins of the plurality of pins passing through a center of the piston. 
     
     
       26. The assembly of claim 22, at least two pins of the plurality of pins being perpendicular with respect to each other. 
     
     
       27. The assembly of claim 26, a first pin of the plurality of pins being disposed higher than a second pin of the plurality of pins. 
     
     
       28. The assembly of claim 1, the pin being adjustable to allow the piston to translate within a range of 0.010 inches to 0.500 inches. 
     
     
       29. The assembly of claim 10, the sleeve having a tolerance of 0.001 inches between the sleeve and the piston. 
     
     
       30. The assembly of claim 10, the sleeve and the piston being composed of the same material. 
     
     
       31. The assembly of claim 15, the aperture being a groove forming a smaller cross section than the pin. 
     
     
       32. The assembly of claim 1, the working surface being pointed. 
     
     
       33. The assembly of claim 1, the working surface including a cutting element. 
     
     
       34. The assembly of claim 1, further comprising a second piston disposed within the wall and configured to translate relative to the housing. 
     
     
       35. The assembly of claim 34, the second piston being angularly aligned with the piston relative to a longitudinal axis of the housing. 
     
     
       36. The assembly of claim 34, the second piston being offset from the piston in a direction of a longitudinal axis of the housing, at least a part of the second piston overlapping at least a part of the first piston about the longitudinal axis. 
     
     
       37. The assembly of claim 34, the piston being configured to translate independently of the second piston. 
     
     
       38. The assembly of claim 1, the piston being free to move relative to the pin at a specific time period. 
     
     
       39. The assembly of claim 1, the pin configured to limit movement of the piston relative to the housing. 
     
     
       40. The assembly of claim 1, the working surface being oriented toward a longitudinal axis of the housing. 
     
     
       41. A method for using the piston assembly of claim 1, comprising:
 directing a portion of a fluid to the chamber;   moving the piston relative to the pin; and   stopping the moving of the piston relative to the pin by a contact of the pin with an edge of the first passageway.   
     
     
       42. The method of claim 41, further comprising exhausting fluid from the first passageway through an aperture in the pin. 
     
     
       43. The method of claim 41, wherein moving the piston relative to the pin includes moving the piston perpendicular to a rotational axis of the housing within a range of 0.010 inches to 0.500 inches. 
     
     
       44. The method of claim 41, wherein moving the piston relative to the pin includes preventing the piston from rotating within the chamber.