Drilling Components
Patent Information
- Application Number
- JP2024544737
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-01-31
- Filing Date
- 2023-01-30
- Publication Date
- 2025-12-09
AI Technical Summary
Existing drill string components suffer from damage due to bending moments and wear, leading to reduced excavation efficiency and operational life, particularly at the connections where screws are used.
The design of excavation components with a first interconnection portion having a smaller cross-sectional area at one end and a larger cross-sectional area at the other end, along with a hollow interior, to distribute stress and minimize wear, ensuring reliable connection and efficient mechanical movement transmission.
This design enhances the durability and efficiency of the drill string by reducing stress concentration and wear, extending the operational life and maintaining high excavation efficiency.
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Abstract
Description
[Technical field]
[0001] The present invention relates generally to drilling components forming part of a drill string, and more particularly to drilling components configured to interconnect various portions of a drill string. [Background technology]
[0002] Percussion drilling is used to produce long boreholes by a number of elongated drill string rods connected together end to end by interconnecting externally threaded and internally threaded ends. By well-established techniques, the rock is broken by a percussive impact delivered from a rock drill bit attached to one end of the drill string to the rock mass at the bottom of the borehole. Typically, the energy required to break the rock mass is generated by a hydraulically driven piston that contacts the end of the drill string (through a shank adapter) and creates a stress (or shock) wave that propagates through the drill string and ultimately to the bottom rock level. Conventional externally and internally threaded connections are described in EP 2845993, EP 2845991 A1, EP 1259703, EP 1232321, and U.S. Pat. No. 4,968,068.
[0003] When the externally threaded and internally threaded ends of adjacent drill rods are connected to create a drill string, the connection is typically subjected to bending forces during drilling. These bending moments fatigue the connection, leading to failure within the threaded portion of the connection. Drilling efficiency is also affected by the bending moments experienced by the connection. Typically, it is the internally threaded end that is damaged and determines the operational life of the connection. In particular, the stresses in the threads of the externally threaded end are typically high and are transferred to the internally threaded end, thereby increasing the wear of the internally threaded end and leading to failure of the connection.
[0004] It is therefore an object of the present invention to seek to overcome at least some of the deficiencies of current drill string connections with respect to component life and drilling efficiency of the drill string. Summary of the Invention
[0005] The object of the present invention is to provide a drilling component arranged to interconnect parts of a drill string and capable of withstanding load forces acting on the drill string in order to minimize the risk of drill string breakage. A further object is to provide a drilling component with improved resistance to bending moments on the drill string resulting from, for example, hole deviations at the bottom drill rod or shank adapter or strikes by an off-centre drive piston. A further object is to provide drilling components for shoulder contact and bottom contact interconnection systems while forming an integral and reliable unit in the assembled drill string. The present invention further arises from the idea of increasing the service life of the interconnection components and, as a result, the required maintenance intervals. The present invention is further directed to improving drilling efficiency by developing more robust drilling components.
[0006] At least some of these and other objects are achieved by providing a drilling component having the features of the independent claims. Preferred embodiments are defined in the dependent claims.
[0007] Thus, according to a first aspect of the present invention, there is provided a drilling component configured to interconnect a first portion and a second portion of a drill string. The drilling component comprises a first end configured to be arranged to face the first portion of the drill string, the first end comprising a first interconnecting portion configured to engage a corresponding interconnecting portion of the first portion of the drill string. The drilling component of the first aspect further comprises a hollow interior extending along a length of the drill string and configured to form part of a passageway through the drill string. Furthermore, the drilling component comprises a wall defining the hollow interior, the area of a first cross-section of the wall being smaller than an area of a second cross-section of the wall, the first cross-section being disposed between the second cross-section and the first end.
[0008] The drilling component functions to link or interconnect a first portion of the drill string with a second portion of the drill string. References herein to a first portion and a second portion of the drill string may include any component forming an assembled drill string that requires interconnection by a drilling component, such as, but not limited to, a drill rod, a shank adapter, a drill tube, a striking hammer, a drill bit, a shaft or adapter attached to the drive end of the drill string or the bit end of the drill string, etc. For example, along the length of the drill string, the first and second portions interconnected by the drilling component may both be drill rods or drill tubes. At the bottom of the drill string, i.e., closest to the bottom of the borehole, the first portion may be a striking hammer and the second portion may be a drill rod or drill tube. At the top of the drill string, i.e., closest to the mouth of the borehole, the first portion may be a drill rod and the second portion may be a shank adapter. Thus, the drilling component is advantageous in that any combination of the above exemplary first and second portions may be interconnected to form a drill string.
[0009] The drilling components further function to transmit mechanical motion and impact forces through these interconnecting portions of the drill string. Thus, mechanical motion, such as the rotational motion exerted on the drill string by the hydraulically driven piston, and impact forces, such as the shock waves generated by the percussion hammer, may be transmitted from one portion of the drill string through the drilling components to an adjacent portion of the drill string with minimal energy loss. Thus, the transmission of mechanical motion and impact forces enabled by the drilling components results in high drilling efficiency.
[0010] This interconnection is made possible by a first interconnection portion provided at the first end of the drilling component and a mating corresponding interconnection portion. For example, the first interconnection portion may comprise an externally threaded portion and the corresponding interconnection portion may comprise an internally threaded portion, together ensuring a secure connection between the first and second portions of the drill string and improving the drill string's resistance to bending moments. Further embodiments of the first interconnection portion are discussed later in this specification.
[0011] The hollow interior of the drilling component allows for continuity of the passageway along the length of the drill string through each section of the drill string, thus allowing the flushing medium, e.g., air or water, to move unhindered through the length of the drill string, and thus allowing for high drilling efficiency with the hollow interior of the drilling component.
[0012] The walls that define the hollow interior can be interpreted as the material that surrounds the hollow interior and thus surrounds the portion of the passageway formed by said hollow interior. The walls of the drilling component are therefore subjected to stresses and strains caused by bending moments and impact forces occurring along the drillstring during operation. Depending on the type of material along the drilling component and wall parameters such as the material thickness, i.e. the amount of material in the wall, it is possible to distribute the stresses along the wall in order to avoid or at least minimize stress concentrations in certain parts of the wall, which generally contribute to faster wear and higher fatigue rates of the drilling component.
[0013] Thus, the present invention embodies a drilling component in which the area of a first cross-section of the wall is smaller than the area of a second cross-section of the wall, the first cross-section being located between the second cross-section and a first end of the drilling component. Within this specification, the area of a cross-section of the wall relates to the amount of material surrounding the hollow interior of the drilling component at a particular location along the length of the drill string. Thus, the present invention embodies reducing or removing material forming the wall towards the first end of the drilling component facing the first portion of the drill string. As a result, reducing or removing material of the wall towards the first end of the drilling component reduces the stiffness of the wall towards the first end, thereby allowing a greater distribution of stress along the first interconnection portion along the length of the drill string. For example, considering a drilling component representing an externally threaded spigot with an internal bore, the present invention embodies removing a greater amount of material of the wall surrounding the internal bore of the spigot towards the end of the spigot facing the adjacent drill rod to which the spigot is coupled. Reducing the amount of material forming the wall of the spigot towards the end of the spigot weakens the end of the spigot and therefore makes it more susceptible to higher stresses, which in turn relieves some of the stresses caused by the bending moments and impact forces of the drill string at the opposite end of the spigot. Thus, the stress distribution along the drilling component, which is made possible by the optional removal of material towards the first end, i.e. by reducing the cross-sectional area of the wall, results in a higher resistance to wear and damage during operation, which in turn results in a longer service life of the drilling component and a higher drilling efficiency. By reducing the stiffness of the wall towards the first end, the stresses transmitted by the first interconnecting portion to the corresponding interconnecting portion engaged by the first interconnecting portion are further reduced, which can reduce the wear caused to said corresponding interconnecting portion. This in turn can increase the service life of the drilling component and the drill string. Alternatively, removing material towards the first end of the drilling component may be defined in terms of the cross-sectional area of the hollow interior and may be expressed as drilling a larger hole in the drilling component towards the first end.For example, the present invention may embody a drilling component in which a first cross-sectional area of the hollow interior is larger than a second cross-sectional area of the hollow interior, the first cross-sectional area being located between the second cross-sectional area and a first end of the drilling component. The cross-sectional area of the hollow interior towards the first end may also be defined in terms of an inner diameter of the hollow interior of the drilling component in the case of a cylindrical inner bore. For example, the present invention may embody a drilling component in which a first inner diameter of the hollow interior is larger than a second inner diameter of the hollow interior, the first inner diameter being located between the second inner diameter and the first end of the drilling component. The present invention is further advantageous in that it is configured to improve resistance to bending moments and to better withstand stresses resulting from the transmission of impact shock waves both when the components of the drill string are perfectly axially aligned and when they are misaligned, i.e. aligned with a slight lateral offset relative to one another. It will be further appreciated that the drilling component according to the first aspect of the present invention is suitable for various applications of percussion drilling, such as rotary drilling, tophammer drilling, down-the-hole drilling, etc.
[0014] According to an embodiment of the present invention, the first interconnection portion may comprise an externally threaded portion configured to engage with a corresponding interconnection portion of the first portion of the drill string. The externally threaded portion allows a secure connection between the first and second portions of the drill string. The externally threaded portion further allows for efficient transfer of mechanical movement and impact forces to the corresponding interconnection portion it engages, resulting in higher drilling efficiency. For example, the first interconnection portion may correspond to the threads of an externally threaded spigot located at the lower end of the drill rod, i.e., the second portion of the drill string, configured to securely engage with a corresponding internally threaded portion located at the upper end of the adjacent drill rod, i.e., the first portion of the drill string, thereby forming together an integral and secure unit in the assembled drill string. Instead of an externally threaded portion, the first interconnection portion may comprise a conical or polygonal interface, e.g., a tapered drill rod, configured to engage with a corresponding conical or polygonal interface of the first portion of the drill string. Such conical interface engagement provides the same positive connection and greater drilling efficiency as previously described with respect to the externally threaded portion.
[0015] According to an embodiment of the present invention, the drilling component further comprises a second interconnection portion, the second interconnection portion configured to engage with a corresponding interconnection portion of the second portion of the drill string. The second interconnection portion may further comprise an internally threaded portion, the internally threaded portion configured to engage with a corresponding interconnection portion of the second portion of the drill string. The internally threaded portion allows a secure connection between the second and first portions of the drill string. The internally threaded portion further allows an efficient transfer of mechanical movement and impact forces to the corresponding interconnection portion it engages with, resulting in higher drilling efficiency. For example, the second interconnection portion may correspond to an internally threaded portion located at the upper end of the drill rod, i.e., the first portion of the drill string, and is configured to securely engage with a corresponding thread of an externally threaded spigot located at the lower end of the adjacent drill rod, i.e., the second portion of the drill string, thereby forming together an integral and secure unit in the assembled drill string. Instead of an internally threaded portion, the second interconnection portion may comprise a conical or polygonal interface, for example a tapered drill rod, as described in the previous embodiment.
[0016] According to an embodiment of the present invention, the drilling component may comprise a second interconnection part configured to be connected to a rock drill piston interface. Herein, the rock drill piston interface corresponds to a mechanical component that allows the coupling of the first drill rod with a hydraulically driven piston that causes the rotational movement of the drill string during drilling operations. For example, the rock drill interface may correspond to a shank adapter. The second interconnection part of this embodiment is advantageous in that it can transmit mechanical motion from the shank adapter to the drill rod with minimal energy loss. In case of a tophammer drilling application, the second interconnection part of this embodiment can also transmit impact forces from the shank adapter to the drill rod with minimal energy loss. Thus, this embodiment allows for a high drilling efficiency of the drill string.
[0017] According to one embodiment of the invention, the drilling component may comprise a shank, which is adjacent to the first interconnection portion such that the first interconnection portion can be located between the shank and the first end. The shank may be interpreted as a conventional region adjacent to the first interconnection portion, the cross-sectional profile at the transition region in a plane extending in the length direction of the drill string being curved such that the cross-sectional area of the shank decreases axially towards the first interconnection portion. This embodiment is therefore advantageous in that the shank reinforces the drilling component against bending moments by reducing stress concentrations, thus reducing the risk of the drilling component breaking under load.
[0018] According to an embodiment of the invention, the drilling component may comprise a radially outwardly projecting shoulder configured to transmit forces along the length of the drill string to a first portion of said drill string. This embodiment is advantageous in that the shoulder provides an interface between the first and second portions of the drill string, enhancing the efficiency of the transmission of impact forces from the second portion of the drill string to the first portion of the drill string. For example, in the case of an externally threaded spigot, the shoulder may be interpreted as projecting radially outwardly from the length of the drill string such that the outer diameter of the shoulder is greater than the outer diameter of the threads of the externally threaded spigot. This embodiment thus enables an interconnection system with shoulder contact.
[0019] According to an embodiment of the invention, the first end may comprise an end face configured to transmit forces along the length of the drill string to a first portion of the drill string. This embodiment is advantageous in that the end face provides an interface between the first and second portions of the drill string, thereby increasing the efficiency of the transmission of impact forces from the second portion of the drill string to the first portion of the drill string. This embodiment thus enables a bottom contact interconnection system.
[0020] According to an embodiment of the invention, the portion of the passageway formed by the hollow interior of the drilling component may be formed by a first region and a second region, the first region being located at the first end and extending at least partially along the first interconnecting portion, and the second region extending between the first region and the second end of the drilling component. Furthermore, the cross-sectional area of the first region may be greater than the cross-sectional area of the second region. This embodiment allows for a variation in the dimensions of the hollow interior of the drilling component between the second region and the first region. This embodiment thus comprises varying the stiffness of the walls forming the hollow interior along the length of the drill string. The first region may thus represent a weakened region of the first interconnecting portion that allows for a distribution of stresses along the first interconnecting portion, thus reducing the stresses transmitted to the corresponding interconnecting portion with which it engages. As a result, the first region has the effect of reducing the wear caused to said corresponding interconnecting portion, thereby increasing the useful life of the drilling component and the drill string. Further, the first region preferably extends from the first end along 20% to 80% of the first interconnect portion, more preferably along 30% to 60% of the first interconnect portion, and most preferably along 50% of the first interconnect portion.
[0021] According to an embodiment of the invention, the second region of the passageway portion may comprise a cylindrical bore. Furthermore, the first region of the passageway portion may comprise a cross-sectional shape conforming to a circle, an ellipse, or a polygon. This embodiment may have different shaped portions of the passageway portion of the drill string formed by the hollow interior of the drilling component. For example, the hollow interior along the second region may comprise a circular cross-sectional profile, e.g., a cylindrical portion of the passageway along the length of the drill string, while the hollow interior along the first region may comprise an elliptical cross-sectional profile, e.g., an elliptical portion of the passageway along the length of the drill string. By varying the shape of the passageway portion formed by the hollow interior of the drilling component, the stress distribution along the first interconnection portion may be optimized depending on the drilling application, the material of the walls defining the hollow interior, the flushing requirements, etc.
[0022] According to a second aspect of the present invention there is provided a strike drillstring comprising at least one drilling component as defined according to the first aspect of the present invention For example several drill rods can be connected together by drilling components according to the first aspect to form an integrated, reliable and long lasting drillstring.
[0023] Further objects, features, and advantages of the present invention will become apparent upon review of the following detailed disclosure, drawings, and appended claims. Those skilled in the art will appreciate that different features of the present invention can be combined to create embodiments other than those described below.
[0024] This and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, in which embodiments of the invention are shown. [Brief description of the drawings]
[0025] [Figure 1a-1d] FIG. 2 is a schematic diagram of a possible portion of an assembled drill string including drilling components according to an exemplary embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic diagram of a drilling component arrangement in accordance with an exemplary embodiment of the present invention; [Diagram 3] FIG. 1 is a schematic diagram of a drilling component arrangement in accordance with an exemplary embodiment of the present invention; [Figure 4] 1 is a schematic diagram of an alternative configuration of a drilling component in accordance with an exemplary embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] 1a-1d show possible parts of an assembled drill string for percussion drilling, in which at least one drilling component 110 according to the invention is depicted in use. With reference to FIG. 1a, a part 100 of an assembled drill string is shown formed by a first part 120 and a second part 130 interconnected to each other by the drilling component 110. In FIG. 1a, the first part 120 and the second part 130 represent a drill rod. The drilling component 110 comprises a first end facing the first part 120 and a first interconnecting part 160 shown with an externally threaded part. The drilling component 110 further comprises a second interconnecting part 170 shown with an internally threaded part that can interconnect with the externally threaded part of the first interconnecting part 160. The drilling component 110 is further shown with a hollow interior 150, which is defined by a material or wall surrounding the hollow interior 150 and extends along the length 140 of the drill string, forming a portion of a passageway extending throughout the drill string. Thus, mechanical movement and impact forces can be transferred from the second portion 130 to the first portion 120 by positive engagement of the first interconnecting portion 160 and the corresponding second interconnecting portion 170. Referring now to FIG. 1b, there is shown a portion 101 of an assembled drill string formed by a first portion 121 and a second portion 131 interconnected to each other by the drilling component 110. In FIG. 1b, the first portion 121 represents a drill rod and the second portion 131 represents a shank adapter, i.e., a rock drill piston interface. The drilling component 110 shown in FIG. 1b includes the same characteristics as defined with respect to the drilling component 110 depicted in FIG. 1a. Thus, the drilling component 110 of Figure 1b comprises a second interconnection portion 170 interconnected to the shank adapter 131 by engagement of the first interconnection portion 160 of the shank adapter 131. Referring now to Figure 1c, there is shown an assembled drill string portion 102 formed by the first portion 122 and the second portion 132 interconnected to each other by the drilling component 110.In Figure 1c, the first portion 122 represents a striking hammer connected at its end to a drill bit 125 and the second portion 132 represents a drill rod. The drilling component 110 shown in Figure 1c includes the same characteristics as defined with respect to the drilling component 110 depicted in Figure 1a. Thus, the drilling component 110 of Figure 1c comprises a first interconnection portion 160 interconnected to the striking hammer 122 by engagement of a second interconnection portion 170 of the striking hammer 122. Referring now to Figure 1d, there is shown a portion 103 of an assembled drill string formed by three successive drill rods 181, 182, 183 interconnected by the first drilling component 111 and the second drilling component 110 in the length direction 140 of the drill string. FIG. 1d shows a first drilling component 111 interconnecting a first drill rod 181 to a second drill rod 182 by engagement of a first interconnecting portion 161 with a second interconnecting portion 171. The first interconnecting portion 161 is shown with a conical interface that engages with a corresponding conical interface of the second interconnecting portion 171. FIG. 1d further shows a second drilling component 110 interconnecting a second drill rod 182 with a third drill rod 183, the second drilling component 110 including the same characteristics as defined with respect to the drilling component 110 depicted in FIG. 1a.
[0027] Referring now to FIG. 2, a configuration of a drilling component 200 is shown according to an exemplary embodiment of the present invention. The drilling component 200 comprises a first end 260 comprising a first interconnection portion 210 configured to engage a corresponding interconnection portion not shown in FIG. 2. The corresponding interconnection portion may represent a second interconnection portion as described above in FIGS. 1a-1d. In the embodiment shown in FIG. 2, the first interconnection portion 210 extends along the length of the drilling component 200 to a second end 270 of the drilling component 200. The first interconnection portion 210 further comprises an externally threaded portion 221 along its length. Additionally, FIG. 2a shows a hollow interior 230 that extends throughout the drilling component 200 along the length 140 of the drill string and forms part of the internal passage of the drill string when assembled. The hollow interior 230 is defined by a wall 220 that corresponds to the material of the drilling component 200 that surrounds the hollow interior 230. The portion of the passageway formed by the hollow interior 230 includes a portion of the wall 220 that varies in thickness as illustrated in FIG. 2 by a reduction in material at the first end 260, which weakens said first end 260 such that the stiffness of the wall 220 along the first end 260 is reduced compared to the stiffness of the wall 220 along the remainder of the drilling component 200. In other words, the portion of the wall 220 that defines the hollow interior 230 at the first end 260 is formed of less material than the portion of the wall 220 that defines the hollow interior 230 at the second end 270 of the drilling component 200. Thus, when the first cross section 240 of the wall 220 and the second cross section 250 of the wall 220 are located on either side of the changing dimension of the hollow interior 230, the area of the first cross section 240 is smaller than the area of the second cross section 250. In other words, the area of the first cross section 240 of the wall 220 taken between the second cross section 250 and the first end 260 is smaller than the area of the second cross section 250 of the wall 220. For example, the area of the first cross section 240 of the wall 220 may preferably be 20% smaller, and most preferably 30% smaller, than the area of the second cross section 250 of the wall 200. It will be appreciated that both cross sections 240, 250 shown in FIG. 2 are taken perpendicular to the length direction 140 of the drill string.Additionally, the drilling component 200 includes a shank 280 that is adjacent to the first interconnect portion 210 such that the first interconnect portion 210 is disposed between the shank 280 and the first end 260 along the length 140 of the drillstring. The shank 280 is depicted in FIG. 2 as a transition portion of the wall 220 between a radially outwardly projecting shoulder 290 and the first interconnect portion 210. The radially outwardly projecting shoulder 290 shown in FIG. 2 includes a contact surface 295 configured to abut a corresponding surface of an adjacent portion of the drillstring to increase the efficiency of the transmission of impact forces along the drillstring. It will further be appreciated that by reducing the area of the wall 220 of the drilling component 200, stresses generated by bending moments and impact forces can be distributed towards the first end 260, thus reducing stress concentrations at the shank 280 and the start of the threads of the externally threaded portion 221 of the first interconnection portion 210 in the length 140 of the drill string. It will further be appreciated that the drilling component 200 of the embodiment of Figure 2 is integrally formed with the drill rod at the end of which the drilling component 200 is located. Alternative connection methods between the drilling component 200 and the drill rod at the end of which the drilling component 200 is located, such as welding, are also embodied.
[0028] Referring now to Figure 3, a drilling component 300 configuration is shown in accordance with an exemplary embodiment of the present invention. Similar to the drilling component of Figure 2, the drilling component 300 of Figure 3 includes a first interconnection portion 310 depicted in Figure 3 having an externally threaded portion 321 and a wall 320 that defines a hollow interior 330 that extends throughout the drilling component 300 in the length direction 140 of the drill string and forms a portion of the drill string's internal passageway when assembled. The portion of the passageway formed by the hollow interior 330 is formed by a first region 365 and a second region 375, with the first region 365 located at the first end 360 of the drilling component 300 and extending to the middle of the first interconnection portion 310. The second region 375 is shown in Figure 3 extending between the first region 365 and the second end 370 of the drilling component 300. Additionally, the portion of the passageway defined by the hollow interior 330 includes a portion of varying dimensions, illustrated in FIG. 3 by the greater area of the hollow interior 330 in the first region 365 compared to the area of the hollow interior 330 in the second region 375. This increase in area has the effect of weakening the portion of the wall 320 surrounding the first region 365, such that the stiffness of said portion of the wall 320 is reduced compared to the stiffness of the portion of the wall 330 surrounding the second region 375. Thus, the cross-sectional area of the first cross section 340 of the first region 365 of the hollow interior 330 is greater than the cross-sectional area of the second cross section 350 of the second region 375. It will be appreciated that both cross sections 340, 350 shown in FIG. 3 are taken perpendicular to the length 140 of the drill string. It will thus be appreciated that the increase in area of the hollow interior 330 of the drilling component 300 from the second region 370 to the first region 360 may distribute stresses generated by bending moments and impact forces towards the portion of the wall 330 surrounding the first region 365, thus reducing stress concentrations in the portion of the wall surrounding the second region 375. Generally, the invention embodied herein by the drilling component 300 may be defined as a junction comprising a cylindrical interior bore and an externally threaded portion, where the diameter of the cylindrical interior bore increases towards the end of the externally threaded portion.
[0029] The walls 320 of the first region 365 have a cylindrical profile. In other words, the first region 365 comprises a cylindrical hole. The walls 320 of the first region 365 are parallel to the walls 320 of the second region 375. The walls 320 of the first region are parallel to the length direction 140. The walls 320 of the second region are parallel to the length direction 140.
[0030] Referring now to Fig. 4, an alternative configuration of a drilling component according to an exemplary embodiment of the present invention is shown. Fig. 4 shows a drilling component 400 characterized similarly to the drilling component 200 of Fig. 2, and further comprising an area of a third cross section 445 of the wall 420 that is smaller than the area of the first cross section 450 of the wall 420 and larger than the area of the second cross section 440 of the wall 420. Thus, Fig. 4 shows a second change in thickness of the wall 420 at a first end 460 of the drilling component 400. Thus, the area of the first cross section 440 of the wall 420 is located between the two larger cross sections of the wall 420, namely the area of the second cross section 450 of the wall 420 and the area of the third cross section 445 of the wall 420. Furthermore, the drilling component 400 comprises an end face 415 made possible by the increased thickness of the wall 420 towards the end of the first interconnection portion 410. End face 415 depicted in FIG. 4 is configured to abut a corresponding surface on an adjacent portion of the drill string to increase the efficiency of the transmission of impact forces along the drill string.
[0031] Those skilled in the art will appreciate that the present invention is in no way limited to the above-described preferred embodiments: on the contrary, many modifications and variations are possible within the scope of the appended claims.
Claims
1. A drilling component (110, 111, 200, 300, 400) configured to interconnect a first portion (120, 121, 122) and a second portion (130, 131, 132) of a drill string, comprising: a first end (260, 360, 460) configured to be positioned facing the first portion, the first end comprising a first interconnection portion (160, 161, 210, 310, 410), the first interconnection portion configured to engage a corresponding interconnection portion (170, 171) of the first portion of the drill string; a hollow interior (150, 151, 230, 330, 430) extending along the length (140) of the drill string and configured to form part of a passageway through the drill string; a wall (220, 320, 420) defining said hollow interior; A drilling component (110, 111, 200, 300, 400) comprising: the passageway portion is formed by a first region (365) having a first cross-section (240, 340, 440) and a second region (375) having a second cross-section (250, 350, 450), the first region (365) being disposed at the first end (260, 360, 460) and extending at least partially along the first interconnecting portion (160, 161, 210, 310, 410), and the second region (375) extending between the first region (365) and a second end (270, 370, 470) of the drilling component (110, 111, 200, 300, 400); the wall (220, 320, 420) of the first region (365) has a cylindrical profile; the walls (220, 320, 420) of the first region (365) are parallel to the walls (220, 320, 420) of the second region (375); the area of the first cross section (240, 340, 440) of the wall is smaller than the area of the second cross section (250, 350, 450) of the wall; The first cross section (240, 340, 440) is disposed between the second cross section (250, 350, 440) and the first end (260, 360, 460). A drilling component (110, 111, 200, 300, 400) characterized in that
2. 2. The drilling component of claim 1, wherein the first interconnection portion comprises an externally threaded portion (221, 321), the externally threaded portion configured to engage the corresponding interconnection portion of the first portion of the drill string.
3. 2. The drilling component of claim 1, further comprising a second interconnection portion (170, 171), said second interconnection portion configured to engage a corresponding interconnection portion of a second portion of the drill string.
4. 4. The drilling component of claim 3, wherein the second interconnection portion comprises an internally threaded portion configured to engage the corresponding interconnection portion of the second portion of the drill string.
5. The drilling component of claim 1 , further comprising a second interconnect portion configured to be connected to a rock drill piston interface.
6. 6. The drilling component of claim 1, further comprising a shank (280), the shank positioned adjacent the first interconnecting portion such that the first interconnecting portion is disposed between the shank and the first end.
7. 6. The drilling component of any one of claims 1 to 5, further comprising a radially outwardly projecting shoulder (290) configured to transfer force along the length of the drill string to the first portion of the drill string.
8. 8. The drilling component of claim 7, wherein the first end comprises an end face (415) configured to transmit force along a length of the drill string to the first portion of the drill string.
9. The drilling component of claim 1 , wherein the cross-sectional area of the first region is greater than the cross-sectional area of the second region.
10. A drilling component according to any one of claims 1 to 5, wherein the second region of the portion of the passage comprises a cylindrical bore.
11. The drilling component of claim 1 , wherein the first region of the portion of the passageway has a cross-sectional shape that corresponds to a circle, an ellipse, or a polygon.
12. A striking drill string comprising at least one drilling component according to any one of claims 1 to 5.