WO2017188876A1 - Retainer means for a drill bit and a method for such retainer means - Google Patents

Retainer means for a drill bit and a method for such retainer means Download PDF

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Publication number
WO2017188876A1
WO2017188876A1 PCT/SE2017/050335 SE2017050335W WO2017188876A1 WO 2017188876 A1 WO2017188876 A1 WO 2017188876A1 SE 2017050335 W SE2017050335 W SE 2017050335W WO 2017188876 A1 WO2017188876 A1 WO 2017188876A1
Authority
WO
WIPO (PCT)
Prior art keywords
retainer means
chuck
drill bit
connection
bit
Prior art date
Application number
PCT/SE2017/050335
Other languages
French (fr)
Inventor
Magnus HÖRMAN
Original Assignee
Lkab Wassara Ab
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 Lkab Wassara Ab filed Critical Lkab Wassara Ab
Priority to AU2017256707A priority Critical patent/AU2017256707B2/en
Priority to CA3021194A priority patent/CA3021194A1/en
Publication of WO2017188876A1 publication Critical patent/WO2017188876A1/en

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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
    • E21B12/00—Accessories for drilling tools
    • 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
    • E21B17/046—Couplings; joints between rod or the like and bit or between rod and rod or the like with ribs, pins, or jaws, and complementary grooves or the like, e.g. bayonet catches
    • 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
    • E21B10/00—Drill bits
    • E21B10/36—Percussion drill bits
    • 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
    • E21B17/07—Telescoping joints for varying drill string lengths; Shock absorbers
    • E21B17/076—Telescoping joints for varying drill string lengths; Shock absorbers between rod or pipe and drill bit

Definitions

  • the present invention concerns a retainer means for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement.
  • the present invention concerns also a method for such a retainer means for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement.
  • a tool of this type demonstrates, for example, a thread for the connections between the different parts of the tool, these threads may be prevented from smooth glide one into the other by a mixture of oil, stone dust and small particles becoming trapped in the threads during the exchange of a drill bit.
  • WO 9858153 Al describes a drill bit with bayonet mount for connection to its associated chuck fastening in which the chuck comprises inwardly facing protrusions that are adapted to be inserted into corresponding grooves in the drill bit.
  • these protrusion glide in a channel that runs along the longitudinal direction of the bit, after which they are displaced in the sideways direction in a transverse channel and finally reach a shorter, partially closed, longitudinal channel.
  • the bit is subsequently connected to further arrangements that ensure that the protrusions cannot be displaced back to the first channel.
  • WO 2013108127 A2 describes a drill bit that is connected to its associated chuck fastening by means of a splined connection, in which the splined connection is integrated with a recirculation system for pressurised air to the system.
  • the splined connection gives an initially simple connection procedure, but the construction must be supplemented with a locking ring in order to ensure that the bit remains in place, since the splined connection allows free movement between the bit and the chuck in an axial direction.
  • the purpose of the present invention is to provide a retainer means and a connection method for such a connection between a drill bit and a chuck fastening that solve the problems with the prior art technology. It is a further purpose to provide a retainer means and a connection method for such a connection that are secure and reliable, but also rapid and simple to connect and disconnect.
  • the purpose of providing a retainer means is achieved by means of a retainer means for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement.
  • the chuck fastening comprises first retainer means
  • the drill bit comprises a drill head and a shaft that comprises second retainer means and third retainer means.
  • a connection between the chuck fastening and the drill bit can be switched between a disengaged condition and a locked condition.
  • the retainer means is characterised in that driving of the tool leads to the connection between the chuck fastening and the drill bit being set into the locked condition, in which locked condition disengagement of the chuck and the bit is prevented through the first retainer means being brought into interaction with the third retainer means when an axial displacement of the drill bit that leads to disengagement takes place.
  • the first retainer means is a first splined connection arranged at an inner surface of the chuck fastening, which splined connection comprises a number of first spline elements each of which has a first width, and a number of first channels, which first channels are constituted by a distance between two first spline elements.
  • the second retainer means is a second splined connection arranged at the shaft of the drill bit, which splined connection comprises a number of second spline elements each of which has a second width, and a number of second channels, which second channels are constituted by a distance between two second spline elements.
  • first and second retainer means in their roles as splined connection also can satisfy a function as driver elements, which driver elements transfer the rotational motion between the chuck and bit.
  • a design of retainer means in the form of a splined connection is advantageous since it then can permit an axial motion between chuck and bit at the same time as they are held at a fixed rotational position relative to each other during operation.
  • the rotating tool is a tool of rock drill type or similar, since the drill bit can then provide a hammer effect against the rock.
  • the second width of the second spline elements is smaller than a first channel width of the first channels.
  • the second retainer means can, by means of rotation of the chuck relative to the bit, be displaced with an angular displacement within the first channels.
  • the first retainer means and the second retainer means are always compelled to be brought into interaction as a consequence of the rotation of the tool.
  • This is advantageous, since a splined connection in which the first retainer means is always brought into interaction with the second retainer means during rotational operation is obtained, but a certain rotation is permitted when the tool is not in operation.
  • This is advantageous since it makes possible a displacement between the condition at which disengagement is possible and the locked condition, by means of the said rotation.
  • the third retainer means comprises a number of radially protruding pegs arranged at the shaft of the drill bit.
  • each peg has a form that is essentially the same as the form of a first channel at the first splined connection. This has the advantage that the location of the said pegs can be used to control the orientation of a rotation of the bit in which a connection between the bit and the chuck is possible.
  • the number of pegs is the same as the number of first channels.
  • the rotating tool is a down-the-hole (DTH) drill.
  • the DTH drill is a water-powered DTH drill.
  • the purpose of providing a method is provided with a method for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement, whereby the chuck fastening comprises first retainer means, and the drill bit comprises a drill head and a shaft that comprises second retainer means and third retainer means, whereby the shaft of the drill bit is introduced into the chuck fastening by means of an axial insertion, which leads to a connection being obtained between the bit and the chuck, which connection is in a condition that allows disengagement.
  • the method is characterised in that the connection between the bit and the chuck is set into a locked condition when driving of the tool has been established, in which said locked condition disengagement of the bit and chuck is prevented through the first retainer means being brought into interaction with the third retainer means at an axial disengagement displacement of the drill bit.
  • Figure la shows a schematic view in perspective of an example of a drill bit with second and third retainer means associated with a retainer means according to the present invention.
  • Figure lb shows a schematic view in perspective of an example of a chuck fastening with first retainer means associated with a retainer means according to the present invention.
  • Figure 2a shows a first schematic cross-sectional view of the first, second and third retainer means at a retainer means according to the present invention, which retainer means is in a condition that allows disengagement.
  • Figure 2b shows a first schematic cross-sectional view of the first, second and third retainer means at a retainer means according to the present invention, which retainer means is in a locked condition.
  • Figure 3a shows a second schematic cross-sectional view of the first and second retainer means at a retainer means according to the present invention, which retainer means is in a condition that allows disengagement.
  • Figure 3b shows a second schematic cross-sectional view of first and second retainer means at a retainer means according to the present invention, which retainer means is in a locked condition.
  • Figure 4a shows a third schematic cross-sectional view of first and third retainer means at a retainer means according to the present invention, which retainer means is in a condition that allows disengagement.
  • Figure 4b shows a third schematic cross-sectional view of first and third retainer means at a retainer means according to the present invention, which retainer means is in a locked condition.
  • the present invention relates to a retainer means 1 for the connection between a drill bit 3 and a chuck fastening 5 of a rotating tool, in particular for a rock drill arrangement.
  • the term "drill bit 3" is here used to denote a drill bit according to prior art technology that may be cast as a single piece, that may comprise inserts that may be embedded into the bit, or that may be of a type that comprises fasteners for inserts that can be exchanged.
  • chuck fastening 5" is used to denote a separate chuck or part having the nature of a chuck at a pipe or similar into which it is intended that the drill bit is to 3 fit and be connected to.
  • the term “chuck fastening 5" is used to denote the part of a tool that transfers the rotational driving forces of the rotating tool to the drill bit 3.
  • the chuck fastening 5 comprises, according to the present invention, first retainer means 7, and the drill bit 3 comprises a drill head 9 and a shaft 11 that comprises second retainer means 13 and third retainer means 15.
  • first retainer means 7 and the drill bit 3 comprises a drill head 9 and a shaft 11 that comprises second retainer means 13 and third retainer means 15.
  • the connection between the bit 3 and the chuck 5 can, furthermore, be switched between a condition A that allows disengagement and a locked condition B.
  • the condition A that allows disengagement means that the drill bit 3 can be removed from the chuck fastening 5 by means of a straight displacement of the drill bit 3 in an axial direction away from the chuck fastening 5.
  • the locked condition B means that a straight axial displacement does not release the drill bit 3 from the chuck fastening 5.
  • the drill bit 3 and the chuck fastening 5 are not completely fixed locked to each other when in the locked condition B, as will be realised on reading the description.
  • the first, second and third retainer means 7, 13, 15 are further so designed that driving of the tool leads to the connection between the drill bit 3 and the chuck fastening 5 being placed into the locked condition B, in which locked condition B disengagement of the bit 3 and chuck 5 is prevented through the first retainer means 7 being brought into interaction with the third retainer means 15 at an axial disengagement displacement of the drill bit 3.
  • a user of the tool that carries out this connection also can place the connection into the locked condition B before driving is initiated, if required.
  • the function of the connection can be regarded as it undergoing a transition to ensure that the locked condition B is maintained at the connection when driving of the tool is started.
  • the first retainer means 7 is a first splined connection 7' arranged at an inner surface 17 of the chuck fastening 5, which splined connection 7' comprises a number of first spline elements 19 each of which has a first width 21, and a number of first channels 23.
  • the said first channels 23 are constituted by a distance between two first spline elements 19.
  • the second retainer means 13 is a second splined connection 13' arranged at the shaft 11 of the drill bit 3, which splined connection 13' comprises a number of second spline elements 25 each of which has a second width 27, and a number of second channels 29, which second channels 29 are constituted by a distance between two second spline elements 25.
  • Splined connections as retainer means is prior art technology for the transfer of rotation between a shaft and a chuck in which an axial motion can, at the same time, be made possible.
  • the first and the second spline elements 19, 25 are arranged to enter into interaction with each other around the shaft 11 and the opposing contact surfaces of the chuck 5.
  • first and second spline elements 19, 25 are the same, but the number of second spline elements 25 may be also lower than the number of first spline elements 19: in such cases, however, the numbers of first and second spline elements 19, 25 are always even multiples of one other.
  • the fundamental concept of a splined connection is, however, according to prior art technology, that a transfer by means of contact of the first and second spline elements 19, 25 takes place evenly distributed around the circumference of the shaft 11 of the drill bit 3.
  • the second width 27 of the second spline elements 25 is smaller than a first channel width 31 of the first channels 23. This means that each one of the second spline elements 25 can be displaced with an angular displacement between two consecutive first spline elements 19 in the second channels 29.
  • the rotation of the chuck will displace the first spline elements 19 around a centre of the drill bit 3 until a first side 33 at each one of the first spline elements 19 is brought into interaction with a first side 35 of a neighbouring second spline element 25, which transfers the rotational force to the drill bit 3.
  • a maintained rotation of the chuck 5 will in this way maintain a contact between the first sides 33 of the first spline elements 19 and the first sides 35 of the second spline elements 25. If a rotation of the chuck 5 stops, the drill bit 3 can subsequently be rotated in direction of rotation that is opposite to the driving rotation of the chuck 5, either by means of a manual rotation or with an opposing rotation generated by a reverse operation of the drive motor of the tool. A rotation of the drill bit 3 relative to a fixed location of the chuck fastening 5, opposite to the drive rotation, can continue until second sides 37, 39 of the first and second spline elements 19, 25, respectively, are brought into interaction with each other, which second sides 37, 39 are the sides opposite to the first sides 33, 35 of the relevant element.
  • the third retainer means 15 comprises a number of radially protruding pegs 15' arranged at the shaft 11 of the drill bit 3.
  • the said pegs 15' are located at one end 41 of the shaft 11 and extend in a sideways direction such that each one of them, when seen in an axial direction of the drill bit 3, extends across one end 43 at each one of the second spline elements 25.
  • each peg 15' extends also over a part of each second channel 29 arranged next to the second spline element 25 that it extends across, on the side of the second spline element 25 that lies next to the first side 33 at each one of the second spline elements 25.
  • each peg 15' has a form that is essentially the same as a form of a first channel 23 at the first splined connection.
  • the term "a form” is here used to denote a form of a cross section of the said channels 23 and the pegs 15' when seen in an axial direction of the bit 3 and the chuck 5. This makes it necessary for the pegs 15' during a connection of the bit 3 and the chuck 5 to fit into the first channels 23 in order to permit an insertion of the bit 3 into the chuck 5.
  • the pegs 15' and the second spline elements 25 be arranged relative to each other in such a manner that the second sides 35 of the first spline elements 19 come into alignment with the second sides 39 of the second spline elements 25 during insertion of the bit 3 into the chuck 5, which insertion takes place subsequent to fitting of the pegs 15' into the first channels 23.
  • a connection is in this way established between the bit 3 and the sheath 5, where the connection is in a condition A that allows disengagement.
  • a rotation of the bit 3 relative to the chuck 5 subsequently puts the connection into a locked condition B.
  • this takes place automatically as a consequence of a rotation of the chuck 5 by means of a rotational driving of the rotating tool.
  • the number of pegs 15' is the same as the number of first channels. This leads to a maximum number of stop surfaces 45, 47 that prevent a disengagement of the drill bit 3 when the connection is in the locked condition B being obtained.
  • the rotating tool in which a connection according to the present invention can be used in can, of course, be various types of drill or similar according to prior art technology in which a rotating operation is not interrupted in a condition that would to be able to displace the connection into the disengaged condition. It is preferable that the rotating tool be a DTH drill.
  • the term "DTH drill” is used to denote what is known as a "down the hole” drill, which is prior art drilling technology for rock drilling. It is preferable but not necessary that the connection be intended to be used with a water-driven DTH drill. In this way, a rapid and simple connection is obtained for an environmentally sensitive and efficient drilling technology according to prior art technology. Also other related arrangements and technologies, however, are possible alternatives for the invention, such as a drill driven by pressurised air, a reverse circulation drill, and a combination of these variants.
  • the present invention relates further to a method for the connection of a drill bit 3 and a chuck fastening 5 of a rotating tool, in particular for a rock drill arrangement, whereby the chuck fastening 5 comprises first retainer means 7, and the drill bit 3 comprises a drill head 9 and a shaft 11 that comprises second retainer means 13 and third retainer means 15, whereby the shaft 11 of the drill bit 3 is introduced into the chuck fastening 5 by means of an axial insertion that leads to a connection between the bit 3 and the chuck 5 being obtained, which connection is in a condition A that allows disengagement.
  • the method is characterised in that the connection between the bit 3 and the chuck 5 is set into a locked condition B when driving of the tool has been established, in which locked condition B disengagement of the chuck 5 and the bit 3 is prevented through the first retainer means 7 being brought into interaction with the third retainer means 15 by an axial disengagement displacement of the drill bit 5.
  • the method can in this way be used to connect a drill bit 3 to a chuck fastening 5 without the requirement that the operator place the connection manually into the locked condition B. If a rotating tool is to be used for, for example, a drilling operation, this can take place without further safety precautions being taken, as long as the drilling takes place in a direction that is directed either essentially upwards or in a sideways direction.
  • the method can advantageously be used for automatic exchange of drill bit in which an automated exchange arrangement does not need to carry out many or complicated steps, and it means that a rotational driving can be easily started at the rotating tool before it needs to be directed downwards, if this is necessary.
  • Figure la shows a schematic view in perspective of an example of a drill bit 3 with second and third retainer means 13, 15 associated with a retainer means 1 according to the present invention.
  • the drill bit 3 comprises a drill head 9 and a shaft 11 on which shaft the second and third retainer means 13, 15 are arranged.
  • the second retainer means 13 is designed as a second splined connection comprising second spline elements 25 on the shaft 11 of the drill bit 3.
  • the said spline elements 25 are directed essentially radially outwards and extend along the axial extent of the shaft 11.
  • the said spline elements 25 in this example are six in number and are arranged with an even distribution around a peripheral surface of the shaft 11.
  • Each one of the second spline elements 25 comprises a first side 35, a second side 39 and an end 43, and each one has a second width 27. Furthermore, a distance between two neighbouring second spline elements 25 defines a second channel 29 with a second channel width 49, which width 49 corresponds to the distance between the said two neighbouring second spline elements 25. Furthermore, the shaft 11 demonstrates third retainer means 15, which are designed as radially protruding pegs 15' arranged at one end 41 of the shaft 11.
  • the number of pegs 15' is the same as the number of second spline elements 25, and they are arranged in such a manner that a first side 49 of each peg 15' is aligned with a second side 39 of one second spline element 25 each. Furthermore, the pegs 15' each have a third width 51 that exceeds the second width 27 of the second spline elements 25. This means that they extend across the second width 27 of the second spline elements 25 and a partial width 52 of the second channel 29.
  • the second spline elements 25 and the pegs 15' are, furthermore, separated axially by a distance 53, which distance 53 is a subset of the length of the shaft 11.
  • Figure lb shows a schematic view in perspective of an example of a chuck fastening 5 with first retainer means 7 associated with a retainer means 1 according to the present invention.
  • the chuck 5 according to this example is designed to be used with the drill bit 3 according to Figure la.
  • the chuck 5 comprises a cover 55 with a length that essentially corresponds to the length of the second spline elements 25 of the shaft 11 of the drill bit 3 according to Figure la.
  • the chuck 5 further comprises first retainer means 7 in the form of a first splined connection comprising first spline elements 19.
  • the said first spline elements 19 are arranged at an inner surface 17 of the chuck fastening 5, whereby they extend radially inwards within the chuck 5 and extend axially along essentially the complete inner surface 17 of the chuck 5. Furthermore, the first splined connection comprises spline elements 19 each of which has a first side 33, a second side 37 and a first width 21, and first channels 23, whereby the first channels 23 are defined by a distance between two neighbouring first spline elements 19. The first channels 23 have a first channel width 31, which width 31 corresponds to the distance between two neighbouring said first spline elements 19.
  • the chuck fastening 5 according to Figure lb is a schematic representation of a chuck fastening 5 in the meaning that this chuck 5 may be also a subset of a pipe or a hammer drill or other parts of a rotating tool, in particular of rock drill type.
  • the chuck according to this example may, therefore, comprise additional retainer means for connection onwards to such another pipe or part of a tool without deviating from the distinctive features of the retainer means according to the present invention.
  • the drill bit 3 according to Figure la and the chuck fastening 5 according to Figure lb are designed to be fitted together and to be connected together by means of retainer means 7, 13, 15 of the bit 3 and the chuck 5.
  • each peg 15' of the shaft 11 of the drill bit 3 has a form that is essentially the same as a form of a first channel 23 of the first splined connection.
  • the third width 51 of each peg 15' is in this way essentially the same as each first channel width 31 of the first splined connection. This means that an insertion of the bit 3 into the chuck 5 is possible only if a fit between the pegs 15' and the first channels 23 is obtained.
  • the pegs 15' can
  • each peg 15' are arranged in such a manner that a first side 49 of each peg 15' is aligned with a second side 39 of one second spline element 25 each, and since the pegs 15' and the first channel 23 are adapted to each other, each second side 37, 39 of the first and the second spline elements 19, 25 will come to lie in contact with each other when the bit 3 is completely inserted into the chuck 5.
  • a connection between the bit 3 and the chuck 5 is in this way obtained, which connection is in a condition A that allows disengagement.
  • FIG. 2a shows a first schematic cross-sectional view of the first, second and third retainer means 7, 13, 15 of a retainer means 1 according to the present invention.
  • the retainer means 1 has been placed in Figure 2a in condition A in which disengagement is possible by means of an axial insertion of a drill bit into a chuck fastening according to the connection method according to the present invention.
  • the schematic cross-section has been taken from a schematic retainer means according to the present invention and shows only a representative drawing of how the various retainer means 7, 13, 15 interact with each other during execution of the method, and it excludes in this example other parts of the drill bit and the chuck fastening.
  • This example comprises two first spline elements 19, three second spline elements 25 and three pegs 15'. Furthermore, this example comprises first and second channels 23, 29 between the relevant first and second spline elements 19, 25. According to the method, the drill bit, and thus also the associated second spline elements 25 and pegs 15', are displaced axially into the chuck fastening and the associated first spline elements 19.
  • the relative axial displacement is illustrated in Figure 2a by the arrows P2a between the first spline elements 19', which are drawn with dashed lines, and the first spline elements 19, which are drawn with solid lines in Figure 2a.
  • the method according to the present invention is in this way carried out by means of the said axial displacement in such a manner that the first spline elements 19 pass through the second channels 23 and subsequently run along the second spline elements 25.
  • This axial displacement may take place either manually or with an automated machine adapted for the purpose.
  • FIG. 2b shows a first schematic cross-sectional view of the first, second and third retainer means 7, 13, 15 of a retainer means 1 according to the present invention.
  • the retainer means 1 has been placed in Figure 2b in a locked condition B when driving of the tool has been established.
  • the schematic cross-section can be seen as the same cross-section as in Figure la with the only difference that the connection between the bit 3 and the sheath 5 has been put into the locked condition B by means of operation of the tool.
  • Driving of the associated rotating tool leads to a displacement in the sideways direction of the first spline elements 19 within the second channels 29 until the first sides 33 at each one of the first spline elements 19 are brought into interaction with the first sides 35 of the neighbouring second spline elements 25, and the rotational force is in this way transferred to the second spline elements 25 and the bit 3.
  • Figure 3a shows a second schematic cross-sectional view of first and second retainer means 7, 13 of a retainer means 1 according to the present invention, which retainer means 1 is in a condition A that allows disengagement.
  • the first and second retainer means 7, 13 in this example are first and second splined connections 7', 13', comprising first and second spline elements 19, 25, respectively, and first and second channels 23, 29.
  • the second schematic cross-sectional view has been taken perpendicular to an axial direction of a drill bit 3 and a chuck fastening 5 that are connected to each other by means of the retainer means 1, whereby the cross-section has been taken such that it intersects the second spline elements 25 of the second splined connection 13' of the shaft 11 of the drill bit 3.
  • Figure 3a shows how the second sides 37, 39 of the first and second spline elements 19, 25 lie in contact with each other in the condition A that allows disengagement.
  • the drill bit 3 and the chuck fastening 5 can be disengaged by means of an axial relative disengagement motion between the bit 3 and the sheath 5, which is illustrated more clearly in Figure 4a.
  • Figure 3b shows a second schematic cross-sectional view of first and second retainer means 7, 13 of a retainer means 1 according to the present invention, which retainer means 1 is in a locked condition B.
  • Figure 3b shows the same cross-section as in Figure 3a with the difference that driving of the tool to which the retainer means 1 belongs has initiated an operation that leads to a clockwise rotation of the chuck 5 relative to the bit 3.
  • the said rotation has in Figure 3b, compared with Figure 3a, rotated the first spline elements 19 around a common axis of the bit 3 and chuck 5, such that the first sides 33, 35 of the first and second spline elements 19, 25 are brought into interaction with each other.
  • the said operation has in this way placed the connection into the locked condition B, and further clockwise driving of the chuck 5 results in a transfer of force between the sheath 5 and the bit 3 such that the bit 3 is rotated clockwise by the said operation of the rotating tool.
  • Figure 4a shows a third schematic cross-sectional view of first and third retainer means 7, 15 of a retainer means 1 according to the present invention, which retainer means 1 is in a condition A that allows disengagement.
  • the first and third retainer means 7, 15 in this example are a first splined connection 7', comprising first spline elements 19 and first channels 23, and radially outwardly directed pegs 15' of the shaft 11.
  • the second schematic cross-sectional view has been taken perpendicular to an axial direction of a drill bit 3 and a chuck fastening 5 that are connected to each other by means of the retainer means 1, whereby the cross-section has been taken such that it intersects the pegs 15' of the third retainer means 15 of the shaft 11 of the drill bit 3.
  • Figure 4a shows how the pegs 15' are arranged axially with the first channels 23 of the chuck 5.
  • the chuck 5 in Figure 4a is arranged at the bit 3 in the same manner as in Figure 3a but the section of the bit 3 and the chuck 5 that has been taken is, as has been described, taken through the pegs 15' instead of at the first and second retainer means 7 (the second retainer means is in this way not visible in Figure 4a).
  • the axial alignment between the pegs 15' and the first channels 23 leads to the connection being in the condition A that allows disengagement, and it leads to it being possible to disengage the drill bit 3 and the chuck fastening 5 with an axial relative disengagement motion between the bit 3 and the sheath 5.
  • Such an axial motion leads in this case to the pegs 15' being able to pass out through the first channels 23 of the chuck 5.
  • Figure 4b shows a third schematic cross-sectional view of first and third retainer means 7, 15 at a retainer means 1 according to the present invention, which retainer means 1 is in a locked condition B.
  • Figure 4b shows the same cross-section as in Figure 4a with the difference that driving of the tool to which the retainer means 1 belongs has initiated an operation that leads to a clockwise rotation of the chuck 5 relative to the bit 3. The said rotation has in Figure 4b, compared with Figure 4a, rotated the first spline elements 19 around a common axis of the bit 3 and chuck 5.
  • the said operation has in this way placed the connection into the locked condition B, and further clockwise driving of the chuck 5 results in a transfer of force between the chuck 5 and the bit 3 such that the bit 3 is rotated clockwise by the said operation of the rotating tool.
  • this locked condition B the drill bit 3 and the chuck fastening 5 cannot be disengaged in the event of an axial relative disengagement motion since the pegs 15' and the first channels 23 are not in axial alignment with each other.
  • Such an axial disengagement displacement instead leads to the first spline elements 19 being brought into interaction with rear surfaces 47 of the pegs 15' and preventing further axial disengagement motion between the bit 3 and the sheath 5.

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  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)
  • Gripping On Spindles (AREA)

Abstract

A retainer means for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement, whereby the chuck fastening comprises first retainer means, and the drill bit comprises a drill head and a shaft that comprises second retainer means and third retainer means, whereby a connection between the chuck fastening and the drill bit can be switched between a condition that allows disengagement and a locked condition. Driving of the tool leads to the connection between the chuck fastening and the drill bit being set into the locked condition, in which locked condition disengagement of the chuck and the bit is prevented through the first retainer means being brought into interaction with the third retainer means by an axial disengagement displacement of the drill bit.

Description

RETAINER MEANS FOR A DRILL BIT AND A METHOD FOR SUCH RETAINER MEANS
TECHNICAL AREA
The present invention concerns a retainer means for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement. The present invention concerns also a method for such a retainer means for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement.
BACKGROUND
During the drilling of hard materials such as stone and rock, it is of great importance that the drill bit carrying out the drilling is firmly attached in a safe and reliable manner in order to ensure that a drilling process can continue without the drill bit becoming disengaged from the chuck fastening. It is in the same way important that an exchange of a drill bit is simple to carry out, since these can become worn out and need to be exchanged at regular intervals. Furthermore, it is of great importance that the connection between a drill bit and an associated chuck fastening is designed with a relatively simple technical design, since exchange of a drill bit often takes place in dirty surroundings where the degree of illumination may be a factor. When a drilling operation is carried out in stone or rock, small stones, gravel and dust are produced, and lubrication agents such as various types of oil may be present, which may lead to contaminated tool surfaces. If a tool of this type demonstrates, for example, a thread for the connections between the different parts of the tool, these threads may be prevented from smooth glide one into the other by a mixture of oil, stone dust and small particles becoming trapped in the threads during the exchange of a drill bit.
Two frequently used designs of these types of connection are to use what is known as a locking ring, which locks the drill bit firmly into the chuck, and a connection of the bayonet-mount type. Both of these solutions, however, are associated with certain problems, since they both can easily become dirty as described above. In addition, they can both often be relatively complicated in their design, which may make the exchange of drill bit unnecessarily complicated to carry out, and difficult to carry out by means of an automatic bit-exchange procedure.
RECORD COPY TRANSLATION
(Rule 12.4) WO 9858153 Al describes a drill bit with bayonet mount for connection to its associated chuck fastening in which the chuck comprises inwardly facing protrusions that are adapted to be inserted into corresponding grooves in the drill bit. During connection of the bit and chuck, these protrusion glide in a channel that runs along the longitudinal direction of the bit, after which they are displaced in the sideways direction in a transverse channel and finally reach a shorter, partially closed, longitudinal channel. The bit is subsequently connected to further arrangements that ensure that the protrusions cannot be displaced back to the first channel. This gives an extremely secure and mechanically reliable construction, but the actual connection method is complex and requires several steps. Further, the construction is sensitive to dirt, since the fit has a relatively small tolerance and is complicated.
WO 2013108127 A2 describes a drill bit that is connected to its associated chuck fastening by means of a splined connection, in which the splined connection is integrated with a recirculation system for pressurised air to the system. The splined connection gives an initially simple connection procedure, but the construction must be supplemented with a locking ring in order to ensure that the bit remains in place, since the splined connection allows free movement between the bit and the chuck in an axial direction.
Thus, there is a need for an improved retainer means between a drill bit and a chuck fastening, and for a connection method for such a retainer means, in particular during the drilling of rock, which retainer means and procedure solve the problems with the prior art technology.
SUMMARY OF THE INVENTION
The purpose of the present invention is to provide a retainer means and a connection method for such a connection between a drill bit and a chuck fastening that solve the problems with the prior art technology. It is a further purpose to provide a retainer means and a connection method for such a connection that are secure and reliable, but also rapid and simple to connect and disconnect.
These purposes are achieved with the arrangement that is defined in claim 1 and the method that is defined in claim 9.
The purpose of providing a retainer means is achieved by means of a retainer means for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement. The chuck fastening comprises first retainer means, and the drill bit comprises a drill head and a shaft that comprises second retainer means and third retainer means. Furthermore, a connection between the chuck fastening and the drill bit can be switched between a disengaged condition and a locked condition. The retainer means is characterised in that driving of the tool leads to the connection between the chuck fastening and the drill bit being set into the locked condition, in which locked condition disengagement of the chuck and the bit is prevented through the first retainer means being brought into interaction with the third retainer means when an axial displacement of the drill bit that leads to disengagement takes place. This has the advantage that a reliable retainer means is obtained in which the drill bit cannot be disengaged and in this way become free of the chuck fastening during operation. A further advantage is that the connection is simple to connect as a consequence of the action of moving the connection of bit and chuck between the disengaged condition and the locked condition is carried out automatically by the drive arrangement itself when operation of the tool is initiated. A yet further advantage is that a retainer means is in this way provided that is advantageous for use with automatic exchanges of bit.
According to another distinctive feature, the first retainer means is a first splined connection arranged at an inner surface of the chuck fastening, which splined connection comprises a number of first spline elements each of which has a first width, and a number of first channels, which first channels are constituted by a distance between two first spline elements. Furthermore, the second retainer means is a second splined connection arranged at the shaft of the drill bit, which splined connection comprises a number of second spline elements each of which has a second width, and a number of second channels, which second channels are constituted by a distance between two second spline elements.
This has the advantage that the first and second retainer means in their roles as splined connection also can satisfy a function as driver elements, which driver elements transfer the rotational motion between the chuck and bit. Furthermore, a design of retainer means in the form of a splined connection is advantageous since it then can permit an axial motion between chuck and bit at the same time as they are held at a fixed rotational position relative to each other during operation. This is an advantage when the rotating tool is a tool of rock drill type or similar, since the drill bit can then provide a hammer effect against the rock. According to a further distinctive feature, the second width of the second spline elements is smaller than a first channel width of the first channels.
This has the advantage that the second retainer means can, by means of rotation of the chuck relative to the bit, be displaced with an angular displacement within the first channels. During operation of the rotating tool, the first retainer means and the second retainer means are always compelled to be brought into interaction as a consequence of the rotation of the tool. This is advantageous, since a splined connection in which the first retainer means is always brought into interaction with the second retainer means during rotational operation is obtained, but a certain rotation is permitted when the tool is not in operation. This is advantageous since it makes possible a displacement between the condition at which disengagement is possible and the locked condition, by means of the said rotation.
According to a further distinctive feature, the third retainer means comprises a number of radially protruding pegs arranged at the shaft of the drill bit.
This has the advantage that the said pegs are located in order to be brought into interaction with the first retainer means in the locked condition of the connection and in this way prevent
disengagement of the bit from the chuck in the event of an axial disengagement displacement of the drill bit.
According to a further distinctive feature, each peg has a form that is essentially the same as the form of a first channel at the first splined connection. This has the advantage that the location of the said pegs can be used to control the orientation of a rotation of the bit in which a connection between the bit and the chuck is possible.
According to a further distinctive feature, the number of pegs is the same as the number of first channels.
This has the advantage that a good fit between the bit and the chuck is obtained in which all pegs fit into a channel when the bit and the chuck are connected. Furthermore, the said fit is a precondition for it to be possible to insert the bit axially into the chuck, which makes erroneous orientation of the bit and chuck impossible, since these must fit into each other in order to permit the axial insertion. According to a yet further distinctive feature, the rotating tool is a down-the-hole (DTH) drill.
This has the advantage that a simple and rapid connection is obtained for such a type of drill in which a rapid and simple connection gives a major advantage during drilling operations.
According to a further distinctive feature, the DTH drill is a water-powered DTH drill.
This has the advantage that an environmentally sensitive DTH drill, in which a rapid and simple connection between bit and sheath, is obtained that efficiently binds dust and that is energy- efficient.
The purpose of providing a method is provided with a method for the connection between a drill bit and a chuck fastening of a rotating tool, in particular for a rock drill arrangement, whereby the chuck fastening comprises first retainer means, and the drill bit comprises a drill head and a shaft that comprises second retainer means and third retainer means, whereby the shaft of the drill bit is introduced into the chuck fastening by means of an axial insertion, which leads to a connection being obtained between the bit and the chuck, which connection is in a condition that allows disengagement. The method is characterised in that the connection between the bit and the chuck is set into a locked condition when driving of the tool has been established, in which said locked condition disengagement of the bit and chuck is prevented through the first retainer means being brought into interaction with the third retainer means at an axial disengagement displacement of the drill bit. This has the advantage that a simple and rapid method for connection of a drill bit and a chuck fastening of a rotating tool is obtained. Furthermore, exchange of a bit, for example, is made easier since the said connection method can be carried out in a single step, an axial displacement. When the connection has been placed into a locked condition by means of driving of the tool, a secure connection method is obtained in which locking is guaranteed as soon as operation of the tool is initiated. BRIEF DESCRIPTION OF DRAWINGS
The present invention will now be described in detail with reference to the schematic drawings, where: Figure la shows a schematic view in perspective of an example of a drill bit with second and third retainer means associated with a retainer means according to the present invention.
Figure lb shows a schematic view in perspective of an example of a chuck fastening with first retainer means associated with a retainer means according to the present invention.
Figure 2a shows a first schematic cross-sectional view of the first, second and third retainer means at a retainer means according to the present invention, which retainer means is in a condition that allows disengagement. Figure 2b shows a first schematic cross-sectional view of the first, second and third retainer means at a retainer means according to the present invention, which retainer means is in a locked condition.
Figure 3a shows a second schematic cross-sectional view of the first and second retainer means at a retainer means according to the present invention, which retainer means is in a condition that allows disengagement.
Figure 3b shows a second schematic cross-sectional view of first and second retainer means at a retainer means according to the present invention, which retainer means is in a locked condition.
Figure 4a shows a third schematic cross-sectional view of first and third retainer means at a retainer means according to the present invention, which retainer means is in a condition that allows disengagement.
Figure 4b shows a third schematic cross-sectional view of first and third retainer means at a retainer means according to the present invention, which retainer means is in a locked condition. DETAILED DESCRIPTION OF THE INVENTION
Distinctive feature of the present invention will now be described in detail. Reference numbers mentioned in the description are not to be seen as a limitation of the scope that is protected by the claims, and their sole function is to make it easier to understand the description and the claims.
The present invention relates to a retainer means 1 for the connection between a drill bit 3 and a chuck fastening 5 of a rotating tool, in particular for a rock drill arrangement. The term "drill bit 3" is here used to denote a drill bit according to prior art technology that may be cast as a single piece, that may comprise inserts that may be embedded into the bit, or that may be of a type that comprises fasteners for inserts that can be exchanged. Furthermore, the term "chuck fastening 5" is used to denote a separate chuck or part having the nature of a chuck at a pipe or similar into which it is intended that the drill bit is to 3 fit and be connected to. Furthermore, the term "chuck fastening 5" is used to denote the part of a tool that transfers the rotational driving forces of the rotating tool to the drill bit 3.
Furthermore, the chuck fastening 5 comprises, according to the present invention, first retainer means 7, and the drill bit 3 comprises a drill head 9 and a shaft 11 that comprises second retainer means 13 and third retainer means 15. By means of the said retainer means 7, 13, 15, a connection between the drill bit 3 and the chuck fastening 5 can be achieved that makes possible a transfer of forces from the driving arrangement of the tool to the bit 3 through the chuck 5. The connection between the bit 3 and the chuck 5 can, furthermore, be switched between a condition A that allows disengagement and a locked condition B. The condition A that allows disengagement means that the drill bit 3 can be removed from the chuck fastening 5 by means of a straight displacement of the drill bit 3 in an axial direction away from the chuck fastening 5. The locked condition B means that a straight axial displacement does not release the drill bit 3 from the chuck fastening 5. However, the drill bit 3 and the chuck fastening 5 are not completely fixed locked to each other when in the locked condition B, as will be realised on reading the description.
The first, second and third retainer means 7, 13, 15 are further so designed that driving of the tool leads to the connection between the drill bit 3 and the chuck fastening 5 being placed into the locked condition B, in which locked condition B disengagement of the bit 3 and chuck 5 is prevented through the first retainer means 7 being brought into interaction with the third retainer means 15 at an axial disengagement displacement of the drill bit 3. A user of the tool that carries out this connection also can place the connection into the locked condition B before driving is initiated, if required. In such a case, the function of the connection can be regarded as it undergoing a transition to ensure that the locked condition B is maintained at the connection when driving of the tool is started. According to a distinctive feature of the present invention, the first retainer means 7 is a first splined connection 7' arranged at an inner surface 17 of the chuck fastening 5, which splined connection 7' comprises a number of first spline elements 19 each of which has a first width 21, and a number of first channels 23. The said first channels 23 are constituted by a distance between two first spline elements 19. Furthermore, the second retainer means 13 is a second splined connection 13' arranged at the shaft 11 of the drill bit 3, which splined connection 13' comprises a number of second spline elements 25 each of which has a second width 27, and a number of second channels 29, which second channels 29 are constituted by a distance between two second spline elements 25. Splined connections as retainer means is prior art technology for the transfer of rotation between a shaft and a chuck in which an axial motion can, at the same time, be made possible. The first and the second spline elements 19, 25 are arranged to enter into interaction with each other around the shaft 11 and the opposing contact surfaces of the chuck 5. It is preferable that the numbers of first and second spline elements 19, 25 are the same, but the number of second spline elements 25 may be also lower than the number of first spline elements 19: in such cases, however, the numbers of first and second spline elements 19, 25 are always even multiples of one other. The fundamental concept of a splined connection is, however, according to prior art technology, that a transfer by means of contact of the first and second spline elements 19, 25 takes place evenly distributed around the circumference of the shaft 11 of the drill bit 3.
According to a distinctive feature of the present invention, the second width 27 of the second spline elements 25 is smaller than a first channel width 31 of the first channels 23. This means that each one of the second spline elements 25 can be displaced with an angular displacement between two consecutive first spline elements 19 in the second channels 29. During rotational operation of the tool, the rotation of the chuck will displace the first spline elements 19 around a centre of the drill bit 3 until a first side 33 at each one of the first spline elements 19 is brought into interaction with a first side 35 of a neighbouring second spline element 25, which transfers the rotational force to the drill bit 3. A maintained rotation of the chuck 5 will in this way maintain a contact between the first sides 33 of the first spline elements 19 and the first sides 35 of the second spline elements 25. If a rotation of the chuck 5 stops, the drill bit 3 can subsequently be rotated in direction of rotation that is opposite to the driving rotation of the chuck 5, either by means of a manual rotation or with an opposing rotation generated by a reverse operation of the drive motor of the tool. A rotation of the drill bit 3 relative to a fixed location of the chuck fastening 5, opposite to the drive rotation, can continue until second sides 37, 39 of the first and second spline elements 19, 25, respectively, are brought into interaction with each other, which second sides 37, 39 are the sides opposite to the first sides 33, 35 of the relevant element.
According to a further distinctive feature of the present invention, the third retainer means 15 comprises a number of radially protruding pegs 15' arranged at the shaft 11 of the drill bit 3. The said pegs 15' are located at one end 41 of the shaft 11 and extend in a sideways direction such that each one of them, when seen in an axial direction of the drill bit 3, extends across one end 43 at each one of the second spline elements 25. Furthermore, each peg 15' extends also over a part of each second channel 29 arranged next to the second spline element 25 that it extends across, on the side of the second spline element 25 that lies next to the first side 33 at each one of the second spline elements 25. This means that when one of the first sides 33 of the first spline elements 19 is in contact with the first sides 35 of the second spline elements 25, and a rotation has been established by means of the drive arrangement of the tool, disengagement of the drill bit 3 from the chuck fastening 5 cannot take place. This is prevented in such a case since an axial displacement of the drill bit relative to the chuck will lead to the ends 43 of the first spline elements 19 being brought into interaction with rear surfaces 47 of the pegs 15', which stops further such motion.
According to a further distinctive feature of the present invention, each peg 15' has a form that is essentially the same as a form of a first channel 23 at the first splined connection. The term "a form" is here used to denote a form of a cross section of the said channels 23 and the pegs 15' when seen in an axial direction of the bit 3 and the chuck 5. This makes it necessary for the pegs 15' during a connection of the bit 3 and the chuck 5 to fit into the first channels 23 in order to permit an insertion of the bit 3 into the chuck 5. It is preferable that the pegs 15' and the second spline elements 25 be arranged relative to each other in such a manner that the second sides 35 of the first spline elements 19 come into alignment with the second sides 39 of the second spline elements 25 during insertion of the bit 3 into the chuck 5, which insertion takes place subsequent to fitting of the pegs 15' into the first channels 23. During such an axial insertion, a connection is in this way established between the bit 3 and the sheath 5, where the connection is in a condition A that allows disengagement. A rotation of the bit 3 relative to the chuck 5 subsequently puts the connection into a locked condition B. Thus, this takes place automatically as a consequence of a rotation of the chuck 5 by means of a rotational driving of the rotating tool.
According to a distinctive feature of the present invention, the number of pegs 15' is the same as the number of first channels. This leads to a maximum number of stop surfaces 45, 47 that prevent a disengagement of the drill bit 3 when the connection is in the locked condition B being obtained.
The rotating tool in which a connection according to the present invention can be used in can, of course, be various types of drill or similar according to prior art technology in which a rotating operation is not interrupted in a condition that would to be able to displace the connection into the disengaged condition. It is preferable that the rotating tool be a DTH drill. The term "DTH drill" is used to denote what is known as a "down the hole" drill, which is prior art drilling technology for rock drilling. It is preferable but not necessary that the connection be intended to be used with a water-driven DTH drill. In this way, a rapid and simple connection is obtained for an environmentally sensitive and efficient drilling technology according to prior art technology. Also other related arrangements and technologies, however, are possible alternatives for the invention, such as a drill driven by pressurised air, a reverse circulation drill, and a combination of these variants.
The present invention relates further to a method for the connection of a drill bit 3 and a chuck fastening 5 of a rotating tool, in particular for a rock drill arrangement, whereby the chuck fastening 5 comprises first retainer means 7, and the drill bit 3 comprises a drill head 9 and a shaft 11 that comprises second retainer means 13 and third retainer means 15, whereby the shaft 11 of the drill bit 3 is introduced into the chuck fastening 5 by means of an axial insertion that leads to a connection between the bit 3 and the chuck 5 being obtained, which connection is in a condition A that allows disengagement. The method is characterised in that the connection between the bit 3 and the chuck 5 is set into a locked condition B when driving of the tool has been established, in which locked condition B disengagement of the chuck 5 and the bit 3 is prevented through the first retainer means 7 being brought into interaction with the third retainer means 15 by an axial disengagement displacement of the drill bit 5. The method can in this way be used to connect a drill bit 3 to a chuck fastening 5 without the requirement that the operator place the connection manually into the locked condition B. If a rotating tool is to be used for, for example, a drilling operation, this can take place without further safety precautions being taken, as long as the drilling takes place in a direction that is directed either essentially upwards or in a sideways direction. If a drilling operation is to be carried out downwards, however, either the method must be supplemented with a manual displacement to the locked condition B, or the rotational driving must be started before the drill bit 3 is turned downwards into an essentially downwardly directed drilling. This means that the method can advantageously be used for automatic exchange of drill bit in which an automated exchange arrangement does not need to carry out many or complicated steps, and it means that a rotational driving can be easily started at the rotating tool before it needs to be directed downwards, if this is necessary.
As is apparent, the invention can be modified in different obvious respects, all of them without deviating from the protective scope defined by the attached claims. Consequently, the detailed description is to be regarded as illustrative in its nature, and not limiting.
DETAILED DESCRIPTION OF DRAWINGS
Examples of the present invention will be described below in detail with reference to the attached drawings. As will become apparent, the invention can be modified in different obvious respects, all of them without deviating from the protective scope defined by the attached claims. Consequently, the drawings and the detailed description of these are to be regarded as illustrative in their nature, and not limiting.
Figure la shows a schematic view in perspective of an example of a drill bit 3 with second and third retainer means 13, 15 associated with a retainer means 1 according to the present invention. The drill bit 3 comprises a drill head 9 and a shaft 11 on which shaft the second and third retainer means 13, 15 are arranged. The second retainer means 13 is designed as a second splined connection comprising second spline elements 25 on the shaft 11 of the drill bit 3. The said spline elements 25 are directed essentially radially outwards and extend along the axial extent of the shaft 11. The said spline elements 25 in this example are six in number and are arranged with an even distribution around a peripheral surface of the shaft 11. Each one of the second spline elements 25 comprises a first side 35, a second side 39 and an end 43, and each one has a second width 27. Furthermore, a distance between two neighbouring second spline elements 25 defines a second channel 29 with a second channel width 49, which width 49 corresponds to the distance between the said two neighbouring second spline elements 25. Furthermore, the shaft 11 demonstrates third retainer means 15, which are designed as radially protruding pegs 15' arranged at one end 41 of the shaft 11. The number of pegs 15' is the same as the number of second spline elements 25, and they are arranged in such a manner that a first side 49 of each peg 15' is aligned with a second side 39 of one second spline element 25 each. Furthermore, the pegs 15' each have a third width 51 that exceeds the second width 27 of the second spline elements 25. This means that they extend across the second width 27 of the second spline elements 25 and a partial width 52 of the second channel 29. The second spline elements 25 and the pegs 15' are, furthermore, separated axially by a distance 53, which distance 53 is a subset of the length of the shaft 11.
Figure lb shows a schematic view in perspective of an example of a chuck fastening 5 with first retainer means 7 associated with a retainer means 1 according to the present invention. The chuck 5 according to this example is designed to be used with the drill bit 3 according to Figure la. The chuck 5 comprises a cover 55 with a length that essentially corresponds to the length of the second spline elements 25 of the shaft 11 of the drill bit 3 according to Figure la. The chuck 5 further comprises first retainer means 7 in the form of a first splined connection comprising first spline elements 19. The said first spline elements 19 are arranged at an inner surface 17 of the chuck fastening 5, whereby they extend radially inwards within the chuck 5 and extend axially along essentially the complete inner surface 17 of the chuck 5. Furthermore, the first splined connection comprises spline elements 19 each of which has a first side 33, a second side 37 and a first width 21, and first channels 23, whereby the first channels 23 are defined by a distance between two neighbouring first spline elements 19. The first channels 23 have a first channel width 31, which width 31 corresponds to the distance between two neighbouring said first spline elements 19. The chuck fastening 5 according to Figure lb is a schematic representation of a chuck fastening 5 in the meaning that this chuck 5 may be also a subset of a pipe or a hammer drill or other parts of a rotating tool, in particular of rock drill type. The chuck according to this example may, therefore, comprise additional retainer means for connection onwards to such another pipe or part of a tool without deviating from the distinctive features of the retainer means according to the present invention. The drill bit 3 according to Figure la and the chuck fastening 5 according to Figure lb are designed to be fitted together and to be connected together by means of retainer means 7, 13, 15 of the bit 3 and the chuck 5. For an optimal fit of this connection, each peg 15' of the shaft 11 of the drill bit 3 has a form that is essentially the same as a form of a first channel 23 of the first splined connection. The third width 51 of each peg 15' is in this way essentially the same as each first channel width 31 of the first splined connection. This means that an insertion of the bit 3 into the chuck 5 is possible only if a fit between the pegs 15' and the first channels 23 is obtained. The pegs 15' can
subsequently be inserted axially into the first channels 23 until the drill head 9 is brought into interaction with the chuck 5. Since the pegs 15' are arranged in such a manner that a first side 49 of each peg 15' is aligned with a second side 39 of one second spline element 25 each, and since the pegs 15' and the first channel 23 are adapted to each other, each second side 37, 39 of the first and the second spline elements 19, 25 will come to lie in contact with each other when the bit 3 is completely inserted into the chuck 5. A connection between the bit 3 and the chuck 5 is in this way obtained, which connection is in a condition A that allows disengagement. When driving of the rotating tool is initiated, the rotational force at the chuck 5 will move the first spline elements 19 within the second channels 29 until each first side 33, 35 of the first and second spline elements 19, 25 are instead brought into interaction, which places the connection between the bit and the chuck into a locked condition B. Figure 2a shows a first schematic cross-sectional view of the first, second and third retainer means 7, 13, 15 of a retainer means 1 according to the present invention. The retainer means 1 has been placed in Figure 2a in condition A in which disengagement is possible by means of an axial insertion of a drill bit into a chuck fastening according to the connection method according to the present invention. The schematic cross-section has been taken from a schematic retainer means according to the present invention and shows only a representative drawing of how the various retainer means 7, 13, 15 interact with each other during execution of the method, and it excludes in this example other parts of the drill bit and the chuck fastening. This example comprises two first spline elements 19, three second spline elements 25 and three pegs 15'. Furthermore, this example comprises first and second channels 23, 29 between the relevant first and second spline elements 19, 25. According to the method, the drill bit, and thus also the associated second spline elements 25 and pegs 15', are displaced axially into the chuck fastening and the associated first spline elements 19. The relative axial displacement is illustrated in Figure 2a by the arrows P2a between the first spline elements 19', which are drawn with dashed lines, and the first spline elements 19, which are drawn with solid lines in Figure 2a. The method according to the present invention is in this way carried out by means of the said axial displacement in such a manner that the first spline elements 19 pass through the second channels 23 and subsequently run along the second spline elements 25. This axial displacement may take place either manually or with an automated machine adapted for the purpose.
The displacement continues until the connection is placed into the condition A that allows disengagement, at which condition A each of two first spline elements 19 lies in contact with two of the second spline elements 25 by means of a contact between second sides 37, 39 of each first and second spline element 19, 25. In the event of an axial relative disengagement motion between the bit 3 and the chuck 5 in this condition A, the first spline elements 19 can pass out through the second channels 23 and in this way disengage the bit 3 and the chuck 5 from each other. Figure 2b shows a first schematic cross-sectional view of the first, second and third retainer means 7, 13, 15 of a retainer means 1 according to the present invention. The retainer means 1 has been placed in Figure 2b in a locked condition B when driving of the tool has been established. The schematic cross-section can be seen as the same cross-section as in Figure la with the only difference that the connection between the bit 3 and the sheath 5 has been put into the locked condition B by means of operation of the tool. Driving of the associated rotating tool leads to a displacement in the sideways direction of the first spline elements 19 within the second channels 29 until the first sides 33 at each one of the first spline elements 19 are brought into interaction with the first sides 35 of the neighbouring second spline elements 25, and the rotational force is in this way transferred to the second spline elements 25 and the bit 3. In the event of an axial relative disengagement motion between the bit 3 and the sheath 5 during operation of the rotating tool, which operation in this way places the connection into the locked condition B, disengagement of the bit 3 and the chuck 5 in, in this way, not possible. In the event of such a disengagement motion, the ends 45 of the first spline elements 19 are brought into interaction with the rear surfaces 47 of the pegs 15', which prevents further such motion. This is illustrated with the first spline elements 19', which are drawn with dashed lines in Figure 2b. A connection method is in this way obtained for a connection in which disengagement between bit 3 and sheath 5 is not possible during operation of the rotating tool.
Figure 3a shows a second schematic cross-sectional view of first and second retainer means 7, 13 of a retainer means 1 according to the present invention, which retainer means 1 is in a condition A that allows disengagement. The first and second retainer means 7, 13 in this example are first and second splined connections 7', 13', comprising first and second spline elements 19, 25, respectively, and first and second channels 23, 29. The second schematic cross-sectional view has been taken perpendicular to an axial direction of a drill bit 3 and a chuck fastening 5 that are connected to each other by means of the retainer means 1, whereby the cross-section has been taken such that it intersects the second spline elements 25 of the second splined connection 13' of the shaft 11 of the drill bit 3. Figure 3a shows how the second sides 37, 39 of the first and second spline elements 19, 25 lie in contact with each other in the condition A that allows disengagement. In this condition A that allows disengagement, the drill bit 3 and the chuck fastening 5 can be disengaged by means of an axial relative disengagement motion between the bit 3 and the sheath 5, which is illustrated more clearly in Figure 4a. Figure 3b shows a second schematic cross-sectional view of first and second retainer means 7, 13 of a retainer means 1 according to the present invention, which retainer means 1 is in a locked condition B. Figure 3b shows the same cross-section as in Figure 3a with the difference that driving of the tool to which the retainer means 1 belongs has initiated an operation that leads to a clockwise rotation of the chuck 5 relative to the bit 3. The said rotation has in Figure 3b, compared with Figure 3a, rotated the first spline elements 19 around a common axis of the bit 3 and chuck 5, such that the first sides 33, 35 of the first and second spline elements 19, 25 are brought into interaction with each other. The said operation has in this way placed the connection into the locked condition B, and further clockwise driving of the chuck 5 results in a transfer of force between the sheath 5 and the bit 3 such that the bit 3 is rotated clockwise by the said operation of the rotating tool. In this locked condition B, the drill bit 3 and the chuck fastening 5 cannot be disengaged in the event of an axial relative disengagement motion between the bit 3 and the sheath 5, which is illustrated more clearly in Figure 4b. Figure 4a shows a third schematic cross-sectional view of first and third retainer means 7, 15 of a retainer means 1 according to the present invention, which retainer means 1 is in a condition A that allows disengagement. The first and third retainer means 7, 15 in this example are a first splined connection 7', comprising first spline elements 19 and first channels 23, and radially outwardly directed pegs 15' of the shaft 11. The second schematic cross-sectional view has been taken perpendicular to an axial direction of a drill bit 3 and a chuck fastening 5 that are connected to each other by means of the retainer means 1, whereby the cross-section has been taken such that it intersects the pegs 15' of the third retainer means 15 of the shaft 11 of the drill bit 3. Figure 4a shows how the pegs 15' are arranged axially with the first channels 23 of the chuck 5. The chuck 5 in Figure 4a is arranged at the bit 3 in the same manner as in Figure 3a but the section of the bit 3 and the chuck 5 that has been taken is, as has been described, taken through the pegs 15' instead of at the first and second retainer means 7 (the second retainer means is in this way not visible in Figure 4a). The axial alignment between the pegs 15' and the first channels 23 leads to the connection being in the condition A that allows disengagement, and it leads to it being possible to disengage the drill bit 3 and the chuck fastening 5 with an axial relative disengagement motion between the bit 3 and the sheath 5. Such an axial motion leads in this case to the pegs 15' being able to pass out through the first channels 23 of the chuck 5.
Figure 4b shows a third schematic cross-sectional view of first and third retainer means 7, 15 at a retainer means 1 according to the present invention, which retainer means 1 is in a locked condition B. Figure 4b shows the same cross-section as in Figure 4a with the difference that driving of the tool to which the retainer means 1 belongs has initiated an operation that leads to a clockwise rotation of the chuck 5 relative to the bit 3. The said rotation has in Figure 4b, compared with Figure 4a, rotated the first spline elements 19 around a common axis of the bit 3 and chuck 5. The said operation has in this way placed the connection into the locked condition B, and further clockwise driving of the chuck 5 results in a transfer of force between the chuck 5 and the bit 3 such that the bit 3 is rotated clockwise by the said operation of the rotating tool. In this locked condition B, the drill bit 3 and the chuck fastening 5 cannot be disengaged in the event of an axial relative disengagement motion since the pegs 15' and the first channels 23 are not in axial alignment with each other. Such an axial disengagement displacement instead leads to the first spline elements 19 being brought into interaction with rear surfaces 47 of the pegs 15' and preventing further axial disengagement motion between the bit 3 and the sheath 5.
The present invention is, of course, not in any manner limited to the prefer embodiments described above: many possibilities of modifications, or combinations of the embodiments described, should be obvious to a person with conventional expertise within the field, without deviating from the fundamental idea of the invention as it is defined in the attached claims.

Claims

1. A retainer means (1) for the connection between a drill bit (3) and a chuck fastening (5) of a rotating tool, in particular for a rock drill arrangement, whereby the chuck fastening (5) comprises first retainer means (7), and the drill bit (3) comprises a drill head (9) and a shaft (11) that comprises second retainer means (13) and third retainer means (15), whereby a connection between the chuck fastening (5) and the drill bit (3) can be switched between a condition (A) that allows disengagement and a locked condition (B),
characterised in that
driving of the tool leads to the connection between the chuck fastening (5) and the drill bit (3) being placed into the locked condition (B), in which locked condition (B) disengagement of the chuck (5) and the drill bit (3) is prevented through the first retainer means (7) being brought into interaction with the third retainer means (15) by an axial disengagement displacement of the drill bit (3).
2. The retainer means (1) according to claim 1, whereby the first retainer means (7) is a first splined connection arranged at an inner surface (17) of the chuck fastening (5), which splined connection comprises a number of first spline elements (19) each of which has a first width (21), and a number of first channels (23), which first channels (23) are constituted by a distance between two first spline elements (19), and whereby the second retainer means (13) is a second splined connection arranged at the shaft (11) of the drill bit (3), which splined connection comprises a number of second spline elements (25) each of which has a second width (27), and a number of second channels (29), which second channels (29) are constituted by a distance between two second spline elements (25).
3. The retainer means (1) according to claim 2, whereby the second width (27) of the second spline elements (25) is smaller than a first channel width (31) of the first channels (23).
4. The arrangement (1) according to any one of the preceding claims, whereby the third
retainer means (15) comprises a number of radially protruding pegs (15') arranged at the shaft (11) of the drill bit (3).
5. The retainer means (1) according to claim 4, whereby each peg (15') has a form that is
essentially the same as a form of a first channel (23) at the first splined connection.
6. The retainer means (1) according to claim 4 or 5, whereby the number of pegs (15') is the same as the number of first channels (23).
The arrangement (1) according to any one of the preceding claims, whereby the rotating tool is a DTH drill.
The retainer means (1) according to claim 7, whereby the DTH drill is a water-driven DTH drill.
A method for the connection of a drill bit (3) and a chuck fastening (5) of a rotating tool, in particular for a rock drill arrangement, whereby the chuck fastening (5) comprises first retainer means (7), and the drill bit (3) comprises a drill head (9) and a shaft (11) that comprises second retainer means (13) and third retainer means (15), whereby the shaft (11) of the drill bit (3) is introduced into the chuck fastening (5) by means of an axial insertion which leads to a connection being obtained between the bit (3) and the chuck (5), which connection is in a condition (A) that allows disengagement,
characterised in that
the connection between the bit (3) and the chuck (5) is placed into a locked condition (B) when driving of the tool has been established, in which locked condition (B) disengagement of the chuck (5) and the drill bit (3) is prevented through the first retainer means (7) being brought into interaction with the third retainer means (15) at an axial disengagement displacement of the drill bit (3).
PCT/SE2017/050335 2016-04-29 2017-04-04 Retainer means for a drill bit and a method for such retainer means WO2017188876A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU2017256707A AU2017256707B2 (en) 2016-04-29 2017-04-04 Retainer means for a drill bit and a method for such retainer means
CA3021194A CA3021194A1 (en) 2016-04-29 2017-04-04 Retainer means for a drill bit and a method for such retainer means

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1650572A SE539881C2 (en) 2016-04-29 2016-04-29 Coupling device for drill bit and method for such coupling.
SE1650572-9 2016-04-29

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WO2017188876A1 true WO2017188876A1 (en) 2017-11-02

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CA (1) CA3021194A1 (en)
CL (1) CL2018003054A1 (en)
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021105109A1 (en) * 2019-11-28 2021-06-03 Mincon International Limited A drill bit assembly for fluid-operated percussion drill tools
RU2817783C1 (en) * 2019-11-28 2024-04-22 Минкон Интернэшнл Лимитед Drilling bit assembly for percussion drilling tools driven by fluid medium and submersible hammer with such assembly

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998005476A1 (en) * 1996-07-31 1998-02-12 Sds Digger Tools Pty. Ltd. Forwardly located bit retention means
WO1998058153A1 (en) * 1997-06-16 1998-12-23 Sds Digger Tools Pty. Ltd. A drill bit with drive and retainer means
WO2007010513A1 (en) * 2005-07-20 2007-01-25 Minroc Technical Promotions Limited A drill bit assembly for fluid-operated percussion drill tools
WO2011023829A1 (en) * 2009-08-31 2011-03-03 Minroc Technical Promotions Limited A drill bit assembly for fluid-operated percussion drill tools
WO2015074920A1 (en) * 2013-11-21 2015-05-28 Chassis Brakes International B.V. Arrangement for the blind assembly of a brake cable by resilient engagement in an abutment element

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998005476A1 (en) * 1996-07-31 1998-02-12 Sds Digger Tools Pty. Ltd. Forwardly located bit retention means
WO1998058153A1 (en) * 1997-06-16 1998-12-23 Sds Digger Tools Pty. Ltd. A drill bit with drive and retainer means
WO2007010513A1 (en) * 2005-07-20 2007-01-25 Minroc Technical Promotions Limited A drill bit assembly for fluid-operated percussion drill tools
WO2011023829A1 (en) * 2009-08-31 2011-03-03 Minroc Technical Promotions Limited A drill bit assembly for fluid-operated percussion drill tools
WO2015074920A1 (en) * 2013-11-21 2015-05-28 Chassis Brakes International B.V. Arrangement for the blind assembly of a brake cable by resilient engagement in an abutment element

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021105109A1 (en) * 2019-11-28 2021-06-03 Mincon International Limited A drill bit assembly for fluid-operated percussion drill tools
RU2817783C1 (en) * 2019-11-28 2024-04-22 Минкон Интернэшнл Лимитед Drilling bit assembly for percussion drilling tools driven by fluid medium and submersible hammer with such assembly

Also Published As

Publication number Publication date
SE539881C2 (en) 2018-01-02
AU2017256707A1 (en) 2018-11-15
CL2018003054A1 (en) 2018-12-21
SE1650572A1 (en) 2017-10-30
AU2017256707B2 (en) 2022-03-24
CA3021194A1 (en) 2017-11-02

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