Drill string components having multiple-thread joints
View Patent ↗Drill string components having at least two threads extending around a body. The leading end of each thread can have a configuration having increased strength and resistance to jamming and cross-threading. In particular, the leading end of each thread can comprise a planar surface normal to the body. The leading end of each thread can provide an abrupt transition to full thread depth that helps reduce or eliminate cross-threading and can be oriented at an angle relative to the axis of the drill string component. Each thread can further provide at least one of a variable thread width and a variable thread pitch configured to create an axial progressive fit. Each thread can also provide a cylindrical thread root and a thread crest that circumscribes a frusta-cone over at least a portion of the axial length of the threads configured to create a radial progressive fit.
1. A threaded drill string component, comprising:
a hollow body having a first end, an opposing second end, and a central axis extending through the hollow body; and
two threads positioned on the first end of the hollow body, wherein:
each of the two threads comprises a plurality of helical turns extending along the first end of the hollow body from a location proximate a leading edge of the first end of the hollow body toward the second end of the hollow body,
each of the two threads has a thread root, a thread crest, a thread pitch, and a thread width, and
each of the two threads has a clearance flank and a pressure flank, the pressure flank being oriented at a negative pressure flank angle.
2. The drill string component as recited in claim 1 , wherein the width of each of the two threads increases uniformly from a first value to a final value across the full axial length of the plurality of helical turns.
3. The drill string component as recited in claim 1 , wherein the width of each of the two threads increases non-uniformly from a first value to a final value across the full axial length of the plurality of helical turns.
4. The drill string component as recited in claim 1 , wherein at least one of the width of each of the two threads and the pitch of each of the two threads increases from a first value to a final value across a portion of the axial length of the plurality of helical turns and remains constant thereafter.
5. The drill string component as recited in claim 1 , wherein the root of each of the two threads circumscribes a cylindrical surface extending the axial length of the plurality of helical turns of the two threads.
6. The drill string component as recited in claim 5 , wherein the crest of each of the two threads circumscribes a frusta-conical surface extending over at least a portion of the axial length of the plurality of helical turns of the two threads, and wherein the generatrix of the frusta-conical surface is a straight line that lies at an angle relative to the central axis extending through the hollow body.
7. The drill string component as recited in claim 1 , wherein the two threads have leading ends that are circumferentially spaced apart proximate the leading edge of the first end of the hollow body, and wherein the leading end of each of the two threads comprises a planar surface that is normal to the hollow body and extends the full thread width to prevent wedging or jamming of the threads.
8. The drill string component as recited in claim 1 , wherein the first end comprises a box end and the threads comprise female threads.
9. The drill string component as recited in claim 1 , wherein the drill string component comprises one of a drill rod, a casing, an adaptor coupling, a reamer, a drill bit, or a locking coupling.
10. The drill string component as recited in claim 7 , wherein the leading end of each of the two threads is offset from the first end of the hollow body by a distance equal to or less than the thread width.
11. A threaded drill string component, comprising:
a hollow body having a first end, an opposing second end, and a central axis extending through the hollow body;
two threads positioned on the first end of the hollow body, wherein:
each of the two threads comprises a plurality of helical turns extending along the first end of the hollow body from a location proximate a leading edge of the first end of the hollow body toward the second end of the hollow body,
each of the two threads has a thread root, a thread crest, a thread pitch, and a thread width,
each of the two threads has a clearance flank and a pressure flank, the pressure flank being oriented at a negative pressure flank angle, and
the crest of each of the two threads circumscribes a frusta-conical surface extending over at least a portion of the axial length of the plurality of helical turns of the two threads, and wherein a generatrix of the frusta-conical surface is a straight line that lies at an angle relative to the central axis extending through the hollow body.
12. The drill string component as recited in claim 11 , wherein the thread width of each of the two threads increases from a first value proximate the leading end over at least a portion of the axial length of the plurality of helical turns of the thread to a final value at a desired point on the thread.
13. The drill string component as recited in claim 12 , wherein the width of each of the two threads increases uniformly from the first value to a final value across the full axial length of the plurality of helical turns.
14. The drill string component as recited in claim 12 , wherein the width of each of the two threads increases non-uniformly from the first value to a final value across the full axial length of the plurality of helical turns.
15. The drill string component as recited in claim 12 , wherein the width of each of the two threads increases non-uniformly from the first value to a final value across a portion of the axial length of the plurality of helical turns and remains constant thereafter.
16. The drill string component as recited in claim 11 , wherein the first end comprises a box end and the two threads comprise female threads.
17. The drill string component as recited in claim 11 , wherein the drill string component comprises one of a drill rod, a casing, an adaptor coupling, a reamer, a drill bit, or a locking coupling.
18. The drill string component as recited in claim 11 , wherein the two threads have leading ends that are circumferentially spaced apart proximate the leading edge of the first end of the hollow body, and wherein the leading end of each of the two threads comprises a planar surface that is normal to the hollow body and extends the full thread width to prevent wedging or jamming of the threads.
19. A threaded drill string component, comprising:
a hollow body having a first end, an opposing second end, and a central axis extending through the hollow body; and
two threads positioned on the first end of the hollow body, wherein:
each of the two threads comprises a plurality of helical turns extending along the first end of the hollow body from a location proximate a leading edge of the first end of the hollow body toward the second end of the hollow body,
each of the two threads has a thread root, a thread crest, a thread pitch, and a thread width, and
each of the two threads has a clearance flank and a pressure flank, the pressure flank being oriented at a pressure angle from about −30 to about 15 degrees.
20. The threaded drill string component of claim 19 , wherein the two threads have leading ends that are circumferentially spaced apart proximate the leading edge of the first end of the hollow body, and wherein the leading end of each of the two threads comprises a planar surface that is normal to the hollow body and extends the full thread width to prevent wedging or jamming of the threads.