EP0220147A2 - Thread coupling for percussion drilling - Google Patents

Thread coupling for percussion drilling Download PDF

Info

Publication number
EP0220147A2
EP0220147A2 EP86850341A EP86850341A EP0220147A2 EP 0220147 A2 EP0220147 A2 EP 0220147A2 EP 86850341 A EP86850341 A EP 86850341A EP 86850341 A EP86850341 A EP 86850341A EP 0220147 A2 EP0220147 A2 EP 0220147A2
Authority
EP
European Patent Office
Prior art keywords
thread
coupling
threads
drill rod
male
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP86850341A
Other languages
German (de)
French (fr)
Other versions
EP0220147A3 (en
Inventor
Sören Liljekvist
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Santrade Ltd
Original Assignee
Santrade Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Santrade Ltd filed Critical Santrade Ltd
Publication of EP0220147A2 publication Critical patent/EP0220147A2/en
Publication of EP0220147A3 publication Critical patent/EP0220147A3/en
Withdrawn legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
    • E21B17/02—Couplings; joints
    • E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
    • E21B17/042—Threaded
    • E21B17/0426—Threaded with a threaded cylindrical portion, e.g. for percussion rods

Definitions

  • the present invention relates to a thread coupling for drill rods for percussion drilling comprising a male thread and a co-operating female thread.
  • the invention also relates to a drill rod intended to be used in such a coupling.
  • the aim of the present invention is to alter the wear configuration in such a way that the thread clearance of the female thread not affects the male thread.
  • aims of the invention are to design the thread coupling in such a way that the thread outlet of the male thread neither causes any bending force nor prevents tightening of the coupling.
  • Fig. 1 discloses a side view of a conventionally designed thread coupling.
  • Fig. 2 illustrates the wear configuration of a conventional rock drill rod.
  • Fig. 3 illustrates the wear configuration of a section along the line III-III in Fig. 2.
  • Fig. 4 illustrates the wear according to a section along the line IV-IV in Fig. 3.
  • Fig. 5 discloses a side view of a thread coupling according to the present invention.
  • Fig. 6 discloses the thread outlet of a male thread of a drill rod according to the invention.
  • Fig. 7 illustrates how the thread outlet of the drill rod according to Fig. 6 can be carried out.
  • Fig. 8. discloses a section along the line VIII-VIII in Fig. 7.
  • Fig. 9 discloses a side view of the thread outlet seen along the line IX-IX in Fig. 8.
  • the conventional thread coupling disclosed in Figs. 1 to 4 comprises a drill rod 100 having a sleeve-shaped end 101 with a female thread 102.
  • the drill rod 100 is connected to a drill rod 103, the pole-shaped end 104 of said drill rod having a male thread 105 that is screwed into the female thread 102.
  • the thread profile of a commonly used rock drill thread has a generally seen trapezoid shape, and contact is present substantially only between the straight contact shoulder 106 of the male thread and a corresponding straight contact shoulder of the female thread.
  • the wear configuration of the threads is consequently as is illustrated by the shaded surfaces 107, 108 in Fig. 2. It has also turned out that the thread outlet of the female thread 102 causes a wear in the shape of a wedge. This is illustrated by the shaded surface 109 in Fig. 2. This wedge-shaped wear counter-acts the tightening of the coupling and has turned out to provide an inclining of the coupling and thus a bending of the drill rod.
  • the wedge-shaped wear surface 109 is illustrated in Fig. 3, and as can be seen from Fig. 4 a pit 110 arises in the contact shoulder adjacent to the thread outlet, said pit having an increasing width in the direction of the circumference.
  • Figs. 5 - 9 is disclosed a preferred embodiment of a thread coupling according to the invention.
  • the coupling comprises a drill rod 10 having a sleeve-shaped end 11 with a female thread 12.
  • the pole-shaped end 14 of the drill rod 13, that is connected to the drill rod 10, comprises a male thread 15 that engages the female thread 12.
  • the contact shoulders 16 are essentially straight.
  • the shoulders 16 have an inclination of 25°-40° relative the drill axis, preferably 35 0 .
  • the threads 12, 15 are internally designed in such a way that an essentially unchanged contact surface between the contact shoulders 16 of the threads 12, 15 is maintained adjacent to the thread clearance of the female thread 12 or the thread outlet of the male thread 15.
  • this is achieved, see Fig. 6, by maintaining the thread profile essentially unchanged up to the thread outlet.
  • conventionally designed drill rods there is a continuous decreasing of the thread profile at the thread outlet, i e both the height and the width of the thread decrease successively from the full profile to the transition of the thread to the unthreaded portion of the rod.
  • Figs. 7 and 8 is illustrated how the maintainance of a full thread profile can be kept up to the thread outlet on the male thread 15 by removing the shaded surfaces 17, 18.
  • the decreasing in width and height is illustrated by the removed portion 19 marked by chain-dotted lines.
  • the same result is likely to be achieved if the male thread is designed to extend out of the portion 11 in a full profile and that the terminating portion of the female thread is removed, said portion having a decreasing width and height.
  • the threads 12, 15 are to be designed internally to extend out of the portion 11 in a full profile and that at the same time the terminating portion of the female thread is removed, said portion having a decreasing width and height.
  • the threads 12, 15 are designed internally in such a way that a wholly number of thread turns are in engagement in the coupling thus guaranteeing that no bending forces appear in the coupling. This means that the threads are designed with a wholly number of turns of a full profile.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)

Abstract

A thread coupling for drill rods for percussion rock drilling comprising a male thread (15) and a co-operating female thread (12). The threads (12, 15) are designed internally in such a way that an essentially unchanged contact surface is maintained between the contact shoulders (16) of the threads adjacent to the thread clearance of the female thread (12) or the thread outlet of the male thread (15).

Description

  • The present invention relates to a thread coupling for drill rods for percussion drilling comprising a male thread and a co-operating female thread. The invention also relates to a drill rod intended to be used in such a coupling.
  • In conventional rock drill rods it has turned out that the thread clearance of the female thread causes a wear in the shape of a wedge thus counter-acting a tightening of the thread coupling resulting in an inclining of the thread coupling.
  • The aim of the present invention is to alter the wear configuration in such a way that the thread clearance of the female thread not affects the male thread.
  • Other aims of the invention are to design the thread coupling in such a way that the thread outlet of the male thread neither causes any bending force nor prevents tightening of the coupling.
  • These and other aims have been achieved by giving the invention the characteristics of the appending claims.
  • The invention is described more in detail in the following, reference being made to the enclosed drawings disclosing an embodiment by way of example. This embodiment is only intended to illustrate the invention that can be modified within the scope of the claims.
  • In the drawings, Fig. 1 discloses a side view of a conventionally designed thread coupling.
  • Fig. 2 illustrates the wear configuration of a conventional rock drill rod.
  • Fig. 3 illustrates the wear configuration of a section along the line III-III in Fig. 2.
  • Fig. 4 illustrates the wear according to a section along the line IV-IV in Fig. 3.
  • Fig. 5 discloses a side view of a thread coupling according to the present invention.
  • Fig. 6 discloses the thread outlet of a male thread of a drill rod according to the invention.
  • Fig. 7 illustrates how the thread outlet of the drill rod according to Fig. 6 can be carried out.
  • Fig. 8. discloses a section along the line VIII-VIII in Fig. 7.
  • Fig. 9 discloses a side view of the thread outlet seen along the line IX-IX in Fig. 8.
  • The conventional thread coupling disclosed in Figs. 1 to 4 comprises a drill rod 100 having a sleeve-shaped end 101 with a female thread 102. The drill rod 100 is connected to a drill rod 103, the pole-shaped end 104 of said drill rod having a male thread 105 that is screwed into the female thread 102.
  • As can be seen from Fig. 2 the thread profile of a commonly used rock drill thread has a generally seen trapezoid shape, and contact is present substantially only between the straight contact shoulder 106 of the male thread and a corresponding straight contact shoulder of the female thread. The wear configuration of the threads is consequently as is illustrated by the shaded surfaces 107, 108 in Fig. 2. It has also turned out that the thread outlet of the female thread 102 causes a wear in the shape of a wedge. This is illustrated by the shaded surface 109 in Fig. 2. This wedge-shaped wear counter-acts the tightening of the coupling and has turned out to provide an inclining of the coupling and thus a bending of the drill rod.
  • The wedge-shaped wear surface 109 is illustrated in Fig. 3, and as can be seen from Fig. 4 a pit 110 arises in the contact shoulder adjacent to the thread outlet, said pit having an increasing width in the direction of the circumference.
  • Tn the coupling of Fig. 1 the male thread 105 extends further than the female thread 102 and thus out of the sleeve-shaped end 101. The same wear configuration and inclining of the drill rod would happen if the female thread instead had an extension further than the male thread.
  • In Figs. 5 - 9 is disclosed a preferred embodiment of a thread coupling according to the invention. In similarity of the conventional design according to Fig. 1 - 4 the coupling comprises a drill rod 10 having a sleeve-shaped end 11 with a female thread 12. The pole-shaped end 14 of the drill rod 13, that is connected to the drill rod 10, comprises a male thread 15 that engages the female thread 12.
  • When tightening of the coupling contact arises along the contact- or pressure shoulder 16 and the corresponding contact shoulders of the female thread 12. In the preferred embodiment the contact shoulders 16 are essentially straight. The shoulders 16 have an inclination of 25°-40° relative the drill axis, preferably 350.
  • According to the invention the threads 12, 15 are internally designed in such a way that an essentially unchanged contact surface between the contact shoulders 16 of the threads 12, 15 is maintained adjacent to the thread clearance of the female thread 12 or the thread outlet of the male thread 15. This means that the contact surface of the thread clearance and the thread outlet resp is equally large as along the rest of the thread. In the preferred embodiment this is achieved, see Fig. 6, by maintaining the thread profile essentially unchanged up to the thread outlet. In conventionally designed drill rods there is a continuous decreasing of the thread profile at the thread outlet, i e both the height and the width of the thread decrease successively from the full profile to the transition of the thread to the unthreaded portion of the rod. In Figs. 7 and 8 is illustrated how the maintainance of a full thread profile can be kept up to the thread outlet on the male thread 15 by removing the shaded surfaces 17, 18. In Fig. 9 the decreasing in width and height is illustrated by the removed portion 19 marked by chain-dotted lines.
  • Alternatively the same result is likely to be achieved if the male thread is designed to extend out of the portion 11 in a full profile and that the terminating portion of the female thread is removed, said portion having a decreasing width and height.
  • According to the preferred embodiment the threads 12, 15 are to be designed internally to extend out of the portion 11 in a full profile and that at the same time the terminating portion of the female thread is removed, said portion having a decreasing width and height.
  • According to the preferred embodiment the threads 12, 15 are designed internally in such a way that a wholly number of thread turns are in engagement in the coupling thus guaranteeing that no bending forces appear in the coupling. This means that the threads are designed with a wholly number of turns of a full profile.

Claims (9)

1. Thread coupling for drill rods for percussion drilling comprising a male thread (15) and a co-operating female thread (12),
characterized in that the threads (12,15) are designed internally in such a way that a substantially unchanged contact surface between the contacting shoulders (16) of the threads (12,15) is maintained adjacent to the thread clearance of the female thread (12) or the thread outlet of the male thread (15).
2. Coupling according to claim 1,
characterized in that the threads (12,15) are so designed internally that a wholly number of thread turns are in engagement in the coupling.
3. Coupling according to claim 1 or 2,
characterized in that the profile of the male thread (15) is maintained substantially unchanged up to the thread outlet.
4. Coupling according to anyone of the previous claims, characterized in that the threads (12,15) have substantially straight contact shoulders (16).
5. Coupling according to claim 4,
characterized in that the contact shoulders (16) are inclined 25°-40° relative the drill axis, preferably in the range of 35°.
6. Drill rod having a male thread (15) and intended to be used in a thread coupling according to claim 1, characterized in that the thread profile is maintained substantially unchanged up to the thread outlet.
7. Drill rod according to claim 6,
characterized in that the thread (15) is designed with a wholly number of turns having a full thread profile.
8. Drill rod according to claim 6 or 7,
characterized in that the thread (15) is designed with an essentially straight pressure shoulder (16).
9. Drill rod according to claim 8,
characterized in that the pressure shoulder (16) has an inclination of 25°-40° relative the drill axis, preferably in the iange of 30°.
EP86850341A 1985-10-17 1986-10-08 Thread coupling for percussion drilling Withdrawn EP0220147A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8504842 1985-10-17
SE8504842A SE8504842L (en) 1985-10-17 1985-10-17 DRILLING ROCK FOR BACKGROUND MOUNTING

Publications (2)

Publication Number Publication Date
EP0220147A2 true EP0220147A2 (en) 1987-04-29
EP0220147A3 EP0220147A3 (en) 1988-11-17

Family

ID=20361778

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86850341A Withdrawn EP0220147A3 (en) 1985-10-17 1986-10-08 Thread coupling for percussion drilling

Country Status (8)

Country Link
EP (1) EP0220147A3 (en)
JP (1) JPS62125192A (en)
CN (1) CN86107149A (en)
AU (1) AU6367286A (en)
BR (1) BR8605070A (en)
FI (1) FI864185A (en)
SE (1) SE8504842L (en)
ZA (1) ZA867682B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999049176A1 (en) * 1998-03-24 1999-09-30 Sandvik Ab; (Publ) Thread joint for percussive drilling, male and female portion for forming part of the joint and method of manufacturing a product having thread for forming part of a thread joint for percussive drilling
EP0979922A2 (en) * 1998-07-30 2000-02-16 Boart Longyear Limited Tube rod
US10584545B2 (en) 2013-09-09 2020-03-10 Sandvik Intellectual Property Ab Drill string with bend resistant coupling

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3095955A1 (en) * 2015-05-22 2016-11-23 Sandvik Intellectual Property AB Threaded coupling end for drill string component

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1645802A (en) * 1925-06-09 1927-10-18 Lewis F Davis Deep-well pump-plunger attachment
US2005498A (en) * 1933-04-28 1935-06-18 Raymond S Hart Detachable bit for rock drills
US2979993A (en) * 1956-04-17 1961-04-18 Sandvikens Jernverks Ab Rock drill bit and method of manufacturing same
US3542406A (en) * 1969-03-26 1970-11-24 Ideal Ind Connector and method
US4397484A (en) * 1982-04-16 1983-08-09 Mobil Oil Corporation Locking coupling system
DE3610880A1 (en) * 1985-04-04 1986-10-16 Santrade Ltd., Luzern THREAD STRUCTURE FOR STONE DRILLING

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1645802A (en) * 1925-06-09 1927-10-18 Lewis F Davis Deep-well pump-plunger attachment
US2005498A (en) * 1933-04-28 1935-06-18 Raymond S Hart Detachable bit for rock drills
US2979993A (en) * 1956-04-17 1961-04-18 Sandvikens Jernverks Ab Rock drill bit and method of manufacturing same
US3542406A (en) * 1969-03-26 1970-11-24 Ideal Ind Connector and method
US4397484A (en) * 1982-04-16 1983-08-09 Mobil Oil Corporation Locking coupling system
DE3610880A1 (en) * 1985-04-04 1986-10-16 Santrade Ltd., Luzern THREAD STRUCTURE FOR STONE DRILLING

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999049176A1 (en) * 1998-03-24 1999-09-30 Sandvik Ab; (Publ) Thread joint for percussive drilling, male and female portion for forming part of the joint and method of manufacturing a product having thread for forming part of a thread joint for percussive drilling
US6293360B1 (en) 1998-03-24 2001-09-25 Sandvik Ab Thread joint percussive drilling equipment
AU746864B2 (en) * 1998-03-24 2002-05-02 Sandvik Intellectual Property Ab Thread joint for percussive drilling, male and female portion for forming part of the joint and method of manufacturing a product having thread for forming part of a thread joint for percussive drilling
CN1095021C (en) * 1998-03-24 2002-11-27 桑德维克公司 Thread joint for percussive drilling, male and female portion for forming part of joint and method for mfg. product having thread for forming part of thread joint for percussive drilling
EP0979922A2 (en) * 1998-07-30 2000-02-16 Boart Longyear Limited Tube rod
EP0979922A3 (en) * 1998-07-30 2001-01-17 Boart Longyear Limited Tube rod
US10584545B2 (en) 2013-09-09 2020-03-10 Sandvik Intellectual Property Ab Drill string with bend resistant coupling

Also Published As

Publication number Publication date
ZA867682B (en) 1987-05-27
FI864185A (en) 1987-04-18
FI864185A0 (en) 1986-10-16
SE8504842D0 (en) 1985-10-17
BR8605070A (en) 1987-07-21
JPS62125192A (en) 1987-06-06
EP0220147A3 (en) 1988-11-17
AU6367286A (en) 1987-04-30
CN86107149A (en) 1987-05-20
SE8504842L (en) 1987-04-18

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Inventor name: LILJEKVIST, SOEREN