WO2022129990A1

WO2022129990A1 - Drill bit with interchangeable segments

Info

Publication number: WO2022129990A1
Application number: PCT/IB2020/061986
Authority: WO
Inventors: Gadi Genadi GREENMAN; Srinath GURUNATH
Original assignee: Groupe Fordia Inc.
Priority date: 2020-12-15
Filing date: 2020-12-15
Publication date: 2022-06-23

Abstract

A drill bit (10) comprising a bit body (14) and a crown (15). The crown (15) includes segments (18) that are removably mounted thereto. The drill bit (10) also includes a lock for selectively locking the segments (18) in the crown (15). Also, a method of using the drill bit (10).

Description

TITLE OF THE INVENTION

Drill bit with interchangeable segments.

FIELD OF THE INVENTION

[001] This invention relates to drill bits. More particularly, the invention relates to a drill bit with interchangeable segments.

BACKGROUND OF THE INVENTION

[002] Most parts of a drill bit are relatively unaffected by the drilling process. In typical operation, only the cutting portions, or segments, for example made of a diamond encrusted matrix, are damaged, or worn down, during the drilling process. Such cutting portions usually represent only a relatively small portion of the drill bit. When the cutting portions are worn down or damaged, or when a drill bit having different properties is needed due to the need to cut or erode a different rock formation, the whole drill bit usually has to be thrown away. In addition, drill bits cannot be modified at customer site for better fit to drilling conditions or rock formation. This is wasteful, and also requires that many drill bits be brought to a drilling site, with the associated weight and bulkiness.

[003] Against this background, there exists a need in the industry to provide an improved drill bit.

[004] An object of the present invention is therefore to provide an improved drill bit. SUMMARY OF THE INVENTION

[005] In a broad aspect, there is provided a drill bit mountable to a drill string, comprising: a bit body mountable to the drill string; a crown including a substantially annular crown body defining opposed crown body proximal and distal end surfaces and opposed crown body radially inwardmost and radially outwardmost surfaces extending therebetween, the crown body defining circumferentially spaced apart segment receiving recesses; the crown also including segments each defining substantially opposed segment proximal and distal end surfaces and opposed segment radially inwardmost and radially outwardmost surfaces extending therebetween, the segments each having a mounting portion and a protruding portion extending therefrom, the mounting portions being each removably received in a respective one of the segment receiving recesses and the protruding portions protruding from the crown body; and a lock movable between locked and unlocked configurations, wherein, in the locked configuration, the lock engages the segments and locks the mounting portions in the segment receiving recesses, and, in the unlocked configuration, the lock is disengaged from the segments so that the mounting portions are removable from the segment receiving recesses. With the lock in the locked configuration, the bit body and the segments are operatively coupled to each other so as to be jointly movable by the drill string.

[006] For example, the drill bit is mountable to a reaming shell, to an outer tube, or to any suitable component of a drill string.

[007] There may also be provided a drill bit wherein the segments each define a locking groove, the lock engaging the locking grooves in the locked configuration and the lock being removed from the locking grooves in the unlocked configuration.

[008] There may also be provided a drill bit wherein the lock includes a substantially annular tang receivable in the locking grooves in the locked configuration, the tang being at different longitudinal locations along the drill bit in the locked and unlocked configurations.

[009] There may also be provided a drill bit wherein the tang and the bit body extend integrally from each other, the bit body and crown body being secured to each other in the locked configuration, and the bit body and crown body being detached from each other in the unlocked configuration.

[0010] There may also be provided a drill bit wherein the crown further includes a crown body mounting sleeve extending proximally from the crown body proximal end surface, the crown body mounting sleeve defining crown body threads and the bit body defines bit body threads, the bit body and crown body threads being threaded to each other in the locked configuration, and the the bit body and crown body threads being detached from each other in the unlocked configuration.

[0011] There may also be provided a drill bit wherein the bit body defines a shoulder facing distally, the crown body mounting sleeve abutting against the shoulder in the locked configuration.

[0012] There may also be provided a drill bit wherein the locking groove extends circumferentially along the segment into the segment end proximal surface, and wherein the crown body proximal end surface is interrupted in register with the segment receiving recesses to allow access to the locking grooves when the segments are received in the segment receiving recesses.

[0013] There may also be provided a drill bit wherein the crown body defines crown body grooves extending in the crown body proximal end surface between the segment receiving recesses, the crown body grooves and locking grooves together forming an annular groove when the segments are received in the segment receiving recesses for receiving the tang thereinto.

[0014] There may also be provided a drill bit wherein the segment receiving recesses extend into the crown body distal end surface between the crown body radially inwardmost and radially outwardmost surfaces.

[0015] There may also be provided a drill bit wherein the protruding portions protrude distally from the crown body when the mounting portions are inserted in the segment receiving recesses.

[0016] There may also be provided a drill bit wherein the protruding portions protrude radially inwardly from the crown body when the mounting portions are inserted in the segment receiving recesses.

[0017] There may also be provided a drill bit wherein the protruding portions protrude radially outwardly from the crown body when the mounting portions are inserted in the segment receiving recesses.

[0018] There may also be provided a drill bit wherein the segment receiving recesses extend along a whole radial thickness of the crown body. [0019] There may also be provided a drill bit wherein the mounting portions are dovetailed into the segment receiving recesses.

[0020] There may also be provided a drill bit wherein the segment receiving recesses have at least a portion thereof tapering in a direction leading radially inwardly.

[0021] There may also be provided a drill bit wherein the segment receiving recesses have at least a portion thereof tapering in a direction leading distally.

[0022] There may also be provided a drill bit wherein each segment receiving recess defines circumferentially opposed recess side surfaces, the recess side surfaces being provided each with a recessed portion, and the segments each define opposed segments side surfaces provided each with a protrusion, wherein the segment and recess side surfaces are complementary shaped so that the mounting portions are received snugly in the segment receiving recesses.

[0023] There may also be provided a drill bit wherein the segment and recess side walls are substantially planar except in the protrusions and recessed portions respectively.

[0024] There may also be provided a drill bit wherein the segments are made entirely of a matrix encrusted with abrasive particles.

[0025] There may also be provided a drill bit wherein the mounting portion includes a bulk metal and the protruding portion includes a matrix encrusted with abrasive particles. [0026] There may also be provided a drill bit wherein the abrasive particles are diamonds.

[0027] There may also be provided a drill bit wherein mechanical interference between the mounting portions and the segment receiving recesses prevents axial and circumferential movements of the mounting portions relative to the segment receiving recesses, and wherein the lock prevents prevents radial movements of the mounting portions relative to the segment receiving recesses in the locked configuration.

[0028] There may also be provided a drill bit wherein, in the unlocked configuration, the mounting portions are removable by moving substantially radially relative to the segment receiving recesses.

[0029] There may also be provided a drill bit wherein in the unlocked configuration, the mounting portions are removable by moving substantially radially outwardly relative to the segment receiving recesses.

[0030] There may also be provided a drill bit wherein the mounting portions extend circumferentially over a smaller extent than the protruding portions.

[0031] In another broad aspect, there is provided a method of assembling a drill bit, comprising: selecting a set of selected segments from a plurality of sets of segments, the selected segments within each set having similar characteristics, the segments from different sets having different characteristics; mounting the selected segments in segment receiving recesses formed in a drill bit crown body; and engaging the selected segments with a lock to lock the selected segments and drill bit crown body to each other.

[0032] There may also be provided a method wherein the different characteristics are selected from the set consisting of different shapes, different dimensions, different hardness, different materials, and combinations thereof.

[0033] There may also be provided a method wherein the selected segments each define a locking groove, engaging the selected segments with the lock including inserting the lock in the locking groove.

[0034] There may also be provided a method wherein the locking groove is arc segment shaped and faces proximally; and the lock includes a tang inserted in the locking groove when the lock is locked.

[0035] There may also be provided a method further comprising disengaging the lock from the selected segments and removing the selected segments from the drill bit crown body.

[0036] For example, the proposed drill bit is usable in core drilling performed through geological formations.

[0037] In another broad aspect, there is provided a drill bit showing a modular construction in which segments can be secured mechanically to a blank, either in a factory environment or by the end user in the field. The segments may be entirely made of a diamond matrix or include a diamond matrix mounted to a metal base. In a variant, a blank includes slots that taper radially inwardly configured to receive radially the segments. A locking ring then engages the segments to lock them mechanically to the blank. The locking ring for examples projects longitudinally into a suitably located recess of each segment. In this variant, the slots block circumferential and longitudinal movements of the segments and the locking ring blocks radial movements of the segments.

[0038] Advantageously, the proposed drill bit allows reusing the same bit body and crown body when the segments have been worn down, or if only one or some of the segments are damaged. Also, in some embodiments, the process of replacing segments can be performed relatively quickly and efficiently, even in the often difficult conditions present at a drilling site.

[0039] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In the appended drawings:

[0041] Figure 1 , in a perspective view, illustrates a drill bit in accordance with an embodiment of the present invention;

[0042] Figure 2, in a perspective exploded view, illustrates the drill bit of FIG. 1 ;

[0043] Figure 3, in a perspective view, illustrates a crown body and crown body mounting sleeve extending therefrom both part of the drill bit of FIG. 1 ; [0044] Figure 4, in an alternative perspective view, illustrates the crown body and crown body mounting sleeve of FIG. 3;

[0045] Figure 5, in a perspective view, illustrates a mounting portion part of a segment part of the drill bit of FIG. 1 ;

[0046] Figure 6, in a perspective view, illustrates a segment incorporating the mounting portion of FIG. 5;

[0047] Figure 7, in an alternative perspective view, illustrates the segment of FIG. 6;

[0048] Figure 8, in a perspective view, illustrates an alternative segment;

[0049] Figure 9, in a perspective view, illustrates integrally formed alternative crown body and crown body mounting sleeve usable in a drill bit similar to the drill bit of FIG. 1 and incorporating the segment of FIG. 8;

[0050] Figure 10, in an alternative perspective view, illustrates the crown body and crown body mounting sleeve of FIG. 9;

[0051] Figure 1 1 , in an axial cross-section view, illustrates the drill bit of FIG. 1 ; and

[0052] Figure 12, in an axial cross-section view, illustrates an alternative drill bit including the crown body of FIG. 9 and the segment of FIG. 8. DETAILED DESCRIPTION

[0053] The terminology distal and proximal refers to the distance from an operator using a proposed drill bit 10 mounted on a drill string 12 in a typical use of the proposed drill bit. Proximal elements are closer to the operator than distal elements. The term “axial” refers to a direction parallel to the longitudinal axis of a drill string 12 to which the proposed drill bit 10 is attached. Also, the terminology “substantially” is used to denote variations in the thus qualified terms that have no significant effect on the principle of operation of the proposed drill bit 10. These variations may be minor variations in design or variations due to mechanical tolerances in manufacturing and use of the drill bit 10. These variations are to be seen with the eye of the reader skilled in the art.

[0054] Referring to FIG. 1 , there is shown a drill bit 10 mountable to a drill string 12, represented schematically in FIG. 1. referring to FIG. 2, the drill bit 10 includes a bit body 14 mountable to the drill string, a crown 15 and a lock 20. The crown 15 includes a substantially annular crown body 16 and segments 18. In some embodiments, the crown 15 also includes a crown body mounting sleeve 32 extending proximally from the crown body 16. The segments 18 are removably secured to the crown body 16 and selectively locked in place by the lock 20. While typically all the segments 18 are removable from the crown body 16 when the lock 20 is unlocked, in alternative embodiments, additional segments or other similar features that are permanently secured to the crown body 16 may provided.

[0055] Referring collectively to FIGS. 3 and 4, the crown body 16 defines opposed crown body proximal and distal end surfaces 22 and 24 and opposed crown body radially inwardmost and radially outwardmost surfaces 26 and 28 extending therebetween. Also, the crown body 16 defines circumferentially spaced apart segment receiving recesses 30 each receiving a respective one of the segments 18.

[0056] In the drill bit 10, the crown body proximal end surface 22 is interrupted in register with the segment receiving recesses 30 by access apertures 38 extending between the segment receiving recesses 30 and the crown body proximal end surface 22 to allow access to the segment receiving recesses 30, so that the lock 20 may engage the segments 18 as further detailed below. For example the access apertures 38 are arc segment shaped. Also, the crown body 16 defines crown body grooves 35 extending in the crown body proximal end surface 22 between the segment receiving recesses 30. Typically, the crown body grooves 35 and access apertures 38 all communicate with each other.

[0057] For allowing attachment of the crown body 16 to the bit body 14, the crown 15 includes a crown body mounting sleeve 32 extending proximally from the crown body proximal end surface 22, for example integrally from the crown body 16. The crown body mounting sleeve 32 defines crown body threads 34. The bit body 14 defines bit body threads 36 (seen on FIG. 2). The bit body and crown body threads 36 and 34 are threaded to each other when the crown body 16 and bit body 14 are secured to each other. In the drawings, the bit body and crown body threads 36 and 34 respectively external and internal threads, but the opposite may be embodied in alternative embodiments. Also, as will be described later, in the drill bit 10, when the crown body 16 and the bit body 14 are fully secured to each other, the lock 20 is in a locked configuration, and when the crown body 16 and the bit body 14 are detached from each other, the lock 20 is in an unlocked configuration. However, in alternative embodiments, the crown body 16 and the bit body 14 may be attached to each other and detached to each other separately from the lock 20, or may be permanently mounted to each other. In such embodiments, the lock 20 is embodied in a piece that is distinct from the bit body 14. Furthermore, while a the crown body mounting sleeve 32 is used to mount the crown 15 and the bit body 14 to each other, in alternative embodiments, the bit body 14 and crown 15 may be mounted to each other in any other suitable manner.

[0058] The segment receiving recesses 30 typically have a shape complementary to that of the segments 18 so that the latter have a part thereof snugly received in the former. The segment receiving recesses 30 extend into the crown body distal end surface 24 between the crown body radially inwardmost and radially outwardmost surfaces 26 and 28. The segments 18 protrude from the segment receiving recesses 30 when secured to the crown body 16. The segments 18 may protrude at least one of distally, radially inwardly or radially outwardly from the crown body 16 when mounted in the segment receiving recesses 30. For example, the segments 18 protrude distally and radially outwardly from the crown body 16 in the drill bit 10, as seen in FIG. 1 1. Segments 18 that don't protrude distally from the crown body 16 act as reamers only, while segments 18 that protrude distally are usable to deepen a bore. In the drill bit 10, the segment receiving recesses 30 extend along a whole radial thickness of the crown body 16. However, in alternative embodiments, the segment receiving recesses 30 may be closed radially inwardly or radially outwardly by a wall formed in the crown body 16.

[0059] The segment receiving recesses 30 are shaped such that mechanical interference between the segments 18 and the segment receiving recesses 30 prevents axial and circumferential movements of the segments 18 relative to the segment receiving recesses 30. Radial movement of the mounting portions relative to the segment receiving recesses are prevented by the lock 20 when the latter is in the locked configuration. In the unlocked configuration, the segments 18 are removable by moving substantially radially relative to the segment receiving recesses 30, either substantially radially outwardly, as in the drill bit 10, or substantially radially inwardly (not shown in the drawings).

[0060] In some embodiments, the segment receiving recesses 30 taper in a direction leading radially inwardly, so that there is only one radial position at which the segments 18 are snugly received in the segment receiving recesses. However, in alternative embodiments, segment receiving recesses 30 have uniform width along their whole radial thickness, or taper radially outwardly.

[0061] Referring to FIG. 11 , the segment receiving recesses 30 define opposed recess side surfaces 40 and 42. In some embodiments, the recess side surfaces 40 and 42 are provided each with a recessed portion 44, shaped to snugly receive a complementarily shaped portion of the segments 18. For example, the recess side surfaces 40 and 42 are substantially planar except in the recessed portion, the latter having for example a substantially C-shaped cross-section circumferentially relative to the drill bit 10, and extend with uniform depth into the remainder of the recess side surfaces 40 and 42. Thus axial movements of the segments 18 in the segment receiving recesses 30 are prevented as the portion of the segments 18 received in the segment receiving recesses 30 is unable to move distally relative to the segment receiving recesses 30 due to mechanical interference.

[0062] In alternative drill bits 10', as seen for example in FIG. 12, the segments 18 have a portion thereof that is dovetailed into the segment receiving recesses 30'. In such embodiments, the segment receiving recesses 30' taper in a direction leading distally, so that the recess side surfaces 42' and 44' thereof converge towards each other in a direction leading distally. The segment receiving recesses 30' may also taper along distally along the entire length of the recess side surfaces 42' and 44', in which case the latter may be both planar, or only along part of their axial extension. The segments 18' of the drill bit 10' are configured to engage the recess side surfaces 42' and 44' so that the tapered shape thereof prevents axial movements therebetween.

[0063] Referring to FIG. 11 , the segments 18 each have a mounting portion 46 and a protruding portion 48. The mounting portions 46 are received in the segment receiving recesses 30, and the protruding portions 48 protrude from the crown body 16. In some embodiments, the mounting and protruding portions 46 and 48 are made of different materials. For example, the mounting portion 46 is metallic, or include a metallic core covered with a thin layer of another material, and the protruding portion 48 is made of a matrix including encrusted abrasive particles, such as diamonds. In such cases, the mounting portion 46, seen in FIG. 5 may define a tiered mounting portion distal surface 50 for enhancing the bond between the protruding portion 48 and the mounting portion 46. In alternative embodiments, as seen in FIG. 12, the segments 18' have mounting portions 46' and protruding portion 48' that have the same or similar compositions, for example by both being made of a matrix including encrusted abrasive particles, such as diamonds, and extend integrally from each other. Below, some characteristics of the segments 18 and 18' are described with respect to the specific embodiments shown in the drawings, but it should be noted that these characteristics may be shared in alternative embodiments both by segments 18 including protruding portion 48 and mounting portion 46 having different compositions, and by segments 18' including protruding portion 48 and the mounting portion 46 made of the same or of similar materials. In some embodiments, the mounting portions 46 extend circumferentially over a smaller extent than the protruding portions 48, so that part of the latter abuts against the crown body distal end surface 24 when the segments 18 are inserted in the segment receiving recesses 30.

[0064] Referring collectively to FIGS. 6 and 7, the segments 18 each define substantially opposed segment proximal and distal end surfaces 52 and 54 and opposed segment radially inwardmost and radially outwardmost surfaces 56 and 58 extending therebetween. The segment distal end surface 54 may be grooved or have any other suitable shape, depending on the type of material in which the drill bit 10 is intended to be used. Furthermore, the segments 18 each define opposed segments side surfaces 60 and 62 each provided with at least one protrusion 64 shaped to be snugly received int the recesses 44. The segment and recess side surfaces 40, 42 and 60, 62 are complementarily shaped so that the mounting portions 46 are received snugly in the segment receiving recesses 30. Alternatively, the segments 18 could be provided with a recess and the segment receiving recesses could be provided with a protrusion.

[0065] In alternative embodiments, as seen in FIG. 8, when the segments 18' are dovetailed in the segment receiving recessed 30', the segments 18' include segment side surfaces 60' and 62' having tapered portions 64' that conform to the shape of the segment receiving recesses 30'. The tapered portions 64' and protrusions 64 may extend radially along all, most of, or only part of the radial extension of respectively the segments 18' and 18.

[0066] Returning to FIG. 7, the segments each define a locking groove 66. The lock 20 engages the locking grooves 66 in the locked configuration and the lock 20 is removed from the locking grooves 66 in the unlocked configuration. Each locking groove 66 extends circumferentially along the segment 18 into the segment proximal end surface 52, between the segment side surfaces 60 and 62, in register with the access aperture 38. The crown body grooves 35, access apertures 38 and locking grooves 66 together form an annular groove 70 (identified in FIG. 11 ) when the segments 18 are received in the segment receiving recesses 30 for receiving the lock 20 thereinto.

[0067] The lock 20 is movable between locked and unlocked configurations, seen respectively in FIGS. 11 and 2 for example. In the locked configuration, the lock 20 engages the segments 18 and locks the mounting portions 46 in the segment receiving recesses 30. In the unlocked configuration, the lock 20 is disengaged from the segments 18 so that the mounting portions 46 are removable from the segment receiving recesses 30. Thus, with the lock in the locked configuration, the bit body 14 and the segments 18 are operatively coupled to each other so as to be jointly movable by the drill string 12.

[0068] In a specific embodiment of the invention, with reference to FIGS. 2 and 11 , the lock 20 takes the form of a substantially annular tang receivable in the locking grooves 66 in the locked configuration. The tang is at different longitudinal locations along the drill bit 10 in the locked and unlocked configurations. The lock 20 may be manufactured as distinct, separate piece securable to the remainder of the drill bit 10 independently from other parts of the drill bit 10. However, in the specific embodiment shown in the drawings, the tang and the bit body 14 extend integrally from each other, so that the bit body 14 and crown body 16 are secured to each other in the locked configuration and detached from each other in the unlocked configuration. Thus, a single piece of material is used to attach the bit body 14 and the crown body 16 to each other and to lock the segments 18.

[0069] Referring to FIG. 2, the bit body includes tubular bit body proximal and distal portions 74 and 76 of different diameters. The bit body proximal portion 74 has a larger diameter than the bit body distal portion 76, so that the bit body 14 defines a shoulder 78 facing distally. Typically, the crown body mounting sleeve 32 abuts against the shoulder 78 in the locked configuration. The bit body proximal portion 74 is provided with the coupling threads 80 for mounting the drill bit 10 to the drill string 12, which is typically threaded at its distal end. However, in alternative embodiments, the drill bit 10 is securable to the drill string 12 in any other suitable manner.

[0070] In an example of use of the drill bit 10, a set of selected segments 18 is selected from a plurality of sets of segments 18. The selected segments 18 within each set having similar characteristics and the segments 18 from different sets have different characteristics. The selected segments 18 are then mounted in segment receiving recesses 30 formed in the crown 15. Afterwards, the selected segments 18 are engaged with the lock 20 to lock the selected segments 18 and crown 15 to each other. For example, the different characteristics are selected from the set consisting of different shapes, different dimensions, different hardness, different materials, and combinations thereof. The characteristics of the selected segments 18 are selected according to the type of drilling to perform. Then, the selected segments 18 are mounted in the segment receiving recesses 30 with the lock 20 in the unlocked configuration, and the selected segments 18 are engaged with the lock 20 to lock the selected segments 18 in the segment receiving recesses 30. If one wants to reuse the same crown and bit bodies 18 and 14, for example if one of more of the selected segments 18 is worn down or damaged, one can unlock the lock 20 so that the latter is disengaged from the selected segments 18 and remove the selected segments 18 from the crown body 16.

[0071] Although the present invention has been described hereinabove by way of exemplary embodiments thereof, it will be readily appreciated that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, the scope of the claims should not be limited by the exemplary embodiments, but should be given the broadest interpretation consistent with the description as a whole. The present invention can thus be modified without departing from the spirit and nature of the subject invention as defined in the appended claims.

Claims

WHAT IS CLAIMED IS:

1 . A drill bit mountable to a drill string, comprising:

- a bit body mountable to the drill string;

- a crown including a substantially annular crown body defining opposed crown body proximal and distal end surfaces and opposed crown body radially inwardmost and radially outwardmost surfaces extending therebetween, the crown body defining circumferentially spaced apart segment receiving recesses;

- the crown also including segments each defining substantially opposed segment proximal and distal end surfaces and opposed segment radially inwardmost and radially outwardmost surfaces extending therebetween, the segments each having a mounting portion and a protruding portion extending therefrom, the mounting portions being each removably received in a respective one of the segment receiving recesses and the protruding portions protruding from the crown body; and

- a lock movable between locked and unlocked configurations, wherein, in the locked configuration, the lock engages the segments and locks the mounting portions in the segment receiving recesses, and, in the unlocked configuration, the lock is disengaged from the segments so that the mounting portions are removable from the segment receiving recesses;

- wherein, with the lock in the locked configuration, the bit body and the segments are operatively coupled to each other so as to be jointly movable by the drill string.

2. The drill bit as defined in claim 1 , wherein the segments each define a locking groove, the lock engaging the locking grooves in the locked configuration and the lock being removed from the locking grooves in the unlocked configuration. The drill bit as defined in claim 2, wherein the lock includes a substantially annular tang receivable in the locking grooves in the locked configuration, the tang being at different longitudinal locations along the drill bit in the locked and unlocked configurations. The drill bit as defined in claim 3, wherein the tang and the bit body extend integrally from each other, the bit body and crown body being secured to each other in the locked configuration, and the bit body and crown body being detached from each other in the unlocked configuration. The drill bit as defined in any one of claims 4, wherein the crown further includes a crown body mounting sleeve extending proximally from the crown body proximal end surface, the crown body mounting sleeve defining crown body threads and the bit body defines bit body threads, the bit body and crown body threads being threaded to each other in the locked configuration, and the the bit body and crown body threads being detached from each other in the unlocked configuration. The drill bit as defined in claim 5, wherein the bit body defines a shoulder facing distally, the crown body mounting sleeve abutting against the shoulder in the locked configuration. The drill bit as defined in any one of claims 3, 4, 5 or 6, wherein the locking groove extends circumferentially along the segment into the segment proximal end surface, and wherein the crown body proximal end surface is interrupted in register with the segment receiving recesses to allow access to the locking grooves when the segments are received in the segment receiving recesses. The drill bit as defined in claim 7, wherein the crown body defines crown body grooves extending in the crown body proximal end surface between the segment receiving recesses, the crown body grooves and locking grooves together forming an annular groove when the segments are received in the segment receiving recesses for receiving the tang thereinto. The drill bit as defined in any one of claims 1 to 8, wherein the segment receiving recesses extend into the crown body distal end surface between the crown body radially inwardmost and radially outwardmost surfaces. The drill bit as defined in claim 9, wherein the protruding portions protrude distally from the crown body when the mounting portions are inserted in the segment receiving recesses. The drill bit as defined in claim 9 or 10, wherein the protruding portions protrude radially inwardly from the crown body when the mounting portions are inserted in the segment receiving recesses. The drill bit as defined in claim 9, 10 or 11 , wherein the protruding portions protrude radially outwardly from the crown body when the mounting portions are inserted in the segment receiving recesses. The drill bit as defined in claim 12, wherein the segment receiving recesses extend along a whole radial thickness of the crown body. The drill bit as defined in any one of claims 1 to 13, wherein the mounting portions are dovetailed into the segment receiving recesses. The drill bit as defined in any one of claims 1 to 14, wherein the segment receiving recesses have at least a portion thereof tapering in a direction leading radially inwardly. The drill bit as defined in any one of claims 1 to 15, wherein the segment receiving recesses have at least a portion thereof tapering in a direction leading distally. The drill bit as defined in any one of claims 1 to 16, wherein each segment receiving recess defines circumferentially opposed recess side surfaces, the recess side surfaces being provided each with a recessed 22 portion, and the segments each define opposed segments side surfaces provided each with a protrusion, wherein the segment and recess side surfaces are complementary shaped so that the mounting portions are received snugly in the segment receiving recesses. The drill bit as defined in claim 17, wherein the segment and recess side walls are substantially planar except in the protrusions and recessed portions respectively. The drill bit as defined in any one of claims 1 to 18, wherein the segments are made entirely of a matrix encrusted with abrasive particles. The drill bit as defined in any one of claims 1 to 18, wherein the mounting portion includes a bulk metal and the protruding portion includes a matrix encrusted with abrasive particles. The drill bit as defined in claim 19 or 20, wherein the abrasive particles are diamonds. The drill bit as defined in any one of claims 1 to 21 , wherein mechanical interference between the mounting portions and the segment receiving recesses prevents axial and circumferential movements of the mounting portions relative to the segment receiving recesses, and wherein the lock prevents prevents radial movements of the mounting portions relative to the segment receiving recesses in the locked configuration. The drill bit as defined in any one of claims 1 to 22, wherein, in the unlocked configuration, the mounting portions are removable by moving substantially radially relative to the segment receiving recesses. The drill bit as defined in any one of claims 1 to 23, wherein in the unlocked configuration, the mounting portions are removable by moving substantially radially outwardly relative to the segment receiving 23 recesses. The drill bit as defined in any one of claims 1 to 24, wherein the mounting portions extend circumferentially over a smaller extent than the protruding portions. A method of assembling a drill bit, comprising:

- selecting a set of selected segments from a plurality of sets of segments, the selected segments within each set having similar characteristics, the segments from different sets having different characteristics;

- mounting the selected segments in segment receiving recesses formed in a drill bit crown body; and

- engaging the selected segments with a lock to lock the selected segments and drill bit crown body to each other. The method as defined in claim 26, wherein the different characteristics are selected from the set consisting of different shapes, different dimensions, different hardness, different materials, and combinations thereof. The method as defined in claim 26 or 27, wherein the selected segments each define a locking groove, engaging the selected segments with the lock including inserting the lock in the locking groove. The method as defined in claim 28, wherein

- the locking groove is arc segment shaped and faces proximally; and

- the lock includes a tang inserted in the locking groove when the lock is locked. The method as defined in any one of claims 26 to 29, further comprising disengaging the lock from the selected segments and removing the selected segments from the drill bit crown body.