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
  • E21B17/043—Threaded with locking means
• • 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B39/00—Locking of screws, bolts or nuts
  • F16B39/22—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening
  • F16B39/28—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening by special members on, or shape of, the nut or bolt
  • F16B39/34—Locking by deformable inserts or like parts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L15/00—Screw-threaded joints; Forms of screw-threads for such joints
  • F16L15/08—Screw-threaded joints; Forms of screw-threads for such joints with supplementary elements

Definitions

• the present invention relates to a thread friction locking device, especially adapted to be mounted in a thread coupling between tubes for percussive drilling.
• Fig.l discloses a section through a device according to the present invention, said device being mounted in a thread coupling
• Fig.2 discloses a top view of a device according to the present invention
• Fig.3 discloses a section along III-III in Fig.2
• Fig.4 discloses in enlarged scale a portion of Fig.2
• Fig.5 discloses a section through the device according to the present invention when the nose of the male thread enters said device, said Figure also being provided with dimensional definitions.
• Fig.l a device 10 according to the invention is shown mounted in a thread coupling between a first tube 11 and a second tube 12.
• the device 10 is in the shape of an annular ring and will be described more in detail further down.
• the first tube 11 has a spigot 13 that is provided with a male thread 14 and the second tube 12 has a boring 15 that is provided with a female thread 16. Both tubes 11 and 12 have central flushing holes 17 that align with each other when the tubes 11, 12 are assembled by the thread coupling.
• the spigot 13 is also provided with a nose 18 at its free end, said nose 18 having a smaller diameter than the rest of the spigot 13.
• the boring 15 is provided with a-thread clearance 19.
• the thread friction locking device 10 according to the present invention is mounted in said thread clearance 19 and when the first and second tubes 11, 12 are assembled by the thread coupling the nose 18 will enter the internal periphery of the device 10 and compress the cross- section of said device 10 in radial direction in its position in the thread clearance 19.
• FIG.2-4 An embodiment of the thread friction locking device 10 according to the present invention is disclosed in Figs.2-4.
• the device 10 is in the shape of an annular ring that has a certain extension in axial direction.
• the outer periphery of the device 10 is smooth but the inner periphery is provided with a number of axially extending grooves 20 that will allow flushing medium, preferably water or air, to enter between the end of the nose 18 and the bottom of the boring 15 and then pass between the device 10 and the nose 18 and further on to the thread coupling, said flushing medium having a cooling effect upon the thread coupling.
• the grooves 20 are spaced apart equally around the circumference by an angle « that is 30°.
• the angle « can of course also have other values within the scope of the invention.
• Fig.4 one groove 20 is shown more in detail and it can be learnt that on one side of the groove 20 there is a bevel
• the outer periphery is rounded at the lower end in Fig.3, i.e. the end that is directed towards the bottom of the boring 15 in mounted position of the device 10, while the upper end in Fig.3, i.e. the end that is directed from the bottom of the boring 15 in mounted position of the device 10, is bevelled at both its outer and inner periphery.
• the bevel 22 on the outer periphery makes the device 10 fit into the thread clearance 19 while the bevel 23 on the inner periphery helps the nose 18 to enter the device 10.
• the bevel 22 is defined by the angle ⁇ in Fig.3, ⁇ preferably being about 25°.
• the bevel 23 is defined by the angle T in Fig.3, T preferably being about 30°.
• the device 10 can be provided with a radiused portion.
• axial grooves 20 on the inner periphery of the device 10 the invention is in no way restricted to such an embodiment.
• the axial grooves can also or instead be provided on the outer periphery of the device 10. It is also possible to have axial channels through the device 10.
• a further possible embodiment is to have helical grooves on the inner and/or outer periphery of the device. The requirement is that flushing medium can pass axially from one end of the device 10 to the other end of the device 10.
• Fig.5 the dimensions of the device 10, the nose 18 and the thread clearance 19 are defined.
• the axial length of the thread friction locking device 10 is marked by 1.
• the cross-sectional thickness is marked by t. The following relationship between t and 1 must be valid: 0,1 i t/1 . 0,6.
• the diameter of the thread clearance 19 is marked by Di.
• the external diameter of the nose 18 is marked by dy.
• the internal diameter of the thread friction locking device 10 is marked by di.
• the external diameter of the thread friction locking device 10 is marked by Dy.
• the following relationship between Di, dy, di and Dy must be valid: 0,55 i (Dy - Di)/(dy - di) i 0,95.
• the thread friction locking device 10 according to the present invention is preferably made out of urethane rubber.
• the material that has been used in our field tests is marketed under the trade mark TREKOLLAN, types 4020 and 4013.
• the material should have a hardness within the interval 80 - 105 ⁇ IHR.
• the tensile stress of the material at 300 % extension in room temperature should be in the interval 10 - 25 MPa.
• the tensile strength of the material in room temperature should be in the interval 20 - 55 MPa.
• the ultimate elongation of the material in room temperature should be in the interval 400 - 850 %.
• the function of the thread friction locking device according to the present invention is best understood when studying Figs.l and 5.
• Fig.5 the nose 18 of the spigot 13 enters the internal periphery of the device 10. Due to the dimensional relationship defined above a certain compression in radial direction of the cross-section of the device 10 will take place.
• the bevel 23, see Fig.3, makes the entering of the nose 18 easier and avoids a compression of the device 10 in axial direction.
• the nose 18 contacts the bottom of the boring 15 and the device 10 is in its operative position. It is at once understood that said compressed device 10 exerts friction forces against an unscrewing relative rotation between the male and the female threads 14 and 16, resp..
• Said design decreases the friction between the device 10 and the nose 18 when the thread coupling is tightened and increases the friction when the thread coupling is unscrewed.

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• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Mechanical Engineering (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Engineering & Computer Science (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Fluid Mechanics (AREA)
• Environmental & Geological Engineering (AREA)
• Physics & Mathematics (AREA)
• Geochemistry & Mineralogy (AREA)
• Earth Drilling (AREA)
• Clamps And Clips (AREA)
• Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)
• Mutual Connection Of Rods And Tubes (AREA)
• Portable Nailing Machines And Staplers (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20378812

Family Applications (1)

Country Status (5)

Cited By (2)

Citations (2)

• 1990
  • 1990-03-09 SE SE9000843A patent/SE470217B/sv not_active IP Right Cessation
• 1991
  • 1991-03-05 AU AU74640/91A patent/AU640768B2/en not_active Ceased
  • 1991-03-05 WO PCT/SE1991/000170 patent/WO1991014073A1/en active Application Filing
  • 1991-03-05 CA CA 2081363 patent/CA2081363A1/en not_active Abandoned
  • 1991-03-08 IE IE077691A patent/IE910776A1/en unknown

Patent Citations (2)

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