The present invention relates to the general field of drilling, and is particularly concerned with a drill bit.
In the geological exploration, mining and construction industries, among others, drill bits 10, an example of which is shown in
As seen in
The flow of water 24 is typically useful in enhancing drilling efficiency and in preserving the integrity of the crown section 14. Therefore, to improve the durability of the crown section 14, it has been found that, in some embodiments of the invention, the water circulation properties of the water 24 are not optimal and need to be enhanced.
Against this background, there exists a need in the industry to provide an improved drill bit. An object of the present invention is therefore to provide an improved drill bit.
A drill bit usable with a fluid, the drill bit comprising a body section, the body section defining a body proximal end and a substantially longitudinally opposed body distal end, the body section defining a body passageway extending substantially longitudinally therethrough for receiving the fluid and conveying the fluid through the body section; a substantially annular crown section extending substantially longitudinally from the body section, the crown section defining a crown distal end and a substantially longitudinally opposed crown proximal end, the crown section extending from the body section with the crown proximal end located substantially adjacent to the body distal end, the crown section defining a crown passageway extending substantially longitudinally therethrough, the crown passageway being in fluid communication with the body passageway for receiving the fluid from the body passageway; and a flow directing component cooperating with the crown section to define a fluid flow channel, the fluid flow channel extending through the crown section substantially radially outwardly from the crown passageway, the fluid flow channel being self-modifiable upon the crown section reaching a predetermined wear threshold so as to modify a flow of the fluid through the fluid flow channel when the crown section reaches the predetermined wear threshold.
Advantageously, the proposed drill bit keeps near optimal fluid flow characteristics through the fluid flow channel over a relatively large range of crown section wear degrees.
Also, the proposed drill bit is relatively easily manufacturable using known methods and materials. Typically, the flow directing component is made out of a material softer than the material making out the crown so as to facilitate destruction or detachment from the crown section of the flow directing component. Furthermore, in some embodiments of the invention, the flow directing component is relatively easily manufacturable at relatively low costs and is easily attachable to the proposed drill bit.
In a variant, the drill bit includes a plurality of slots each having a slot reinforcing member extending substantially circumferentially thereacross. The slots define a plurality of drilling segments, the slot reinforcing members interconnecting the segments to each other. One flow directing component is secured to each of the slot reinforcing members and obstructs partially the corresponding slot.
In some embodiments of the invention, the proposed flow directing component itself is self-destructible upon the crown section reaching the predetermined wear threshold. In other embodiments, the flow directing component is attached to the crown section and is detachable automatically from the crown section upon the crown section reaching the predetermined wear threshold.
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.
In the appended drawings:
Referring to
The drill bit 26 also includes a substantially annular crown section 38 extending substantially longitudinally from the body section 30. The crown section 38 defines a crown distal end 40 and a substantially opposed crown proximal end 42. The crown section 38 extends from the body section 30 with the crown proximal end 42 located substantially adjacent to the body distal end 34. The crown section 38 defines a crown passageway 44 extending substantially longitudinally, the crown passageway 44 being in fluid communication with the body passageway 36 for receiving the fluid 28 from the body passageway 36. A flow directing component 46 cooperates with the crown section 38 to define a fluid flow channel 48. The fluid flow channel 48 extends through the crown section 38 substantially radially outwardly from the crown passageway 44.
The fluid flow channel 48 is self-modifiable upon the crown section 38 reaching a predetermined wear threshold so as to modify the flow of the fluid 28 through the fluid flow channel 48 when the crown section 38 reaches the predetermined wear threshold. In
In the embodiment of the invention shown in the drawings, many substantially circumferentially spaced apart fluid flow channels 48 are defined in the drill bit 26. While a drill bit 26 including eight fluid flow channels 48 is illustrated, it is within the scope of the invention to include any suitable number of the fluid flow channels 48 in the drill bit 26. Furthermore, one or more of the fluid flow channels 48 may include the flow directing component 46, and other ones of the fluid flow channels 48 may be deprived from the flow directing components 46 without departing from the scope of the present invention. The flow directing components 46 may therefore be selectively attachable to the crown section 38 so as to allow flexibility in the fluid flow regulation through the fluid flow channels 48.
In some embodiments of the invention, the flow directing component 46 is self-destructible upon the crown section 38 reaching the predetermined wear threshold. This is achievable, for example, by ensuring that a portion of the flow directing component 46 that is crucial for the attachment of the flow directing component 46 to the crown section 38 is destroyed rapidly when the crown section 38 reaches the predetermined wear threshold. In some embodiments of the invention, this self-destruction is facilitated by using a relatively soft material, such as steel, for the flow directing component 46, while the crown section 38 includes conventional diamond-encrusted matrices that are relatively robust and wear resistant.
In some embodiments of the invention, the flow directing component 46 is attached to the crown section 38. In a variant, the flow directing component 46 is self-destructible, as described hereinabove. In another variant, the flow directing component 46 is detachable automatically from the crown section 38 upon the crown section 38 reaching the predetermined wear threshold. This is achievable, for example, by attaching a relatively robust flow directing component 46 to the crown section 38 through relatively weak attachments. In other embodiments of the invention, the flow directing component 46 extends integrally as a single piece of material from the crown section 38 but is coupled thereto through relatively thin links, as described in greater details hereinbelow.
Typically, the drill bit 26 is usable to drill through a material 50, as shown in
Returning to 4, there is shown a specific example of the drill bit 26 allowing for the achievement of the above described functionalities. The drill bit 26 includes a crown section 38 that defines a radially inwardmost crown inner surface 54. The crown inner surface 54 delimits the crown passageway 44. The crown section 38 also defines a radially outwardmost crown outer surface 56 and one, and typically a set, of slots 58 extend substantially radially through the crown section 38 between the crown inner and outer surfaces 54 and 56, the slots 58 being better seen in
The slots 58 each define substantially opposed slot lateral walls 65 and 66 that are substantially circumferentially spaced apart from each other around the crown section 38 (only one of which is seen in
In some embodiments of the invention, the slots 58 define a slot reinforcing member 70 extending substantially circumferentially across the slot 58, between the slot lateral walls 65 and 66, at a location spaced apart from the slot proximal wall 68.
As better seen in
In some embodiments of the invention, the attachment portion 76 includes an arc segment of a cylinder encircling partially the slot reinforcing member 70. For example, the slot reinforcing member 70 has a substantially cylindrical configuration and the arc segment of the cylinder extends longitudinally further away from the slot proximal wall 68 than the slot reinforcing member 70. In this configuration, when the drill bit 26 has been worn down to a point where the arc segment of the cylinder forming the attachment portion 76 of the flow directing component 46 is exposed to the material through which drilling is performed, the attachment portion 76 is relatively rapidly eroded so as to self-destruct the flow directing component 46 to allow a flow of the fluid 28 through the proximal section of the slot 58.
In the embodiment of the invention shown in the drawings, the flow directing portion 74 includes a pair of legs 78 and 80 each extending from the attachment portion 76, the legs 80 typically extending up to the slot proximal wall 68 so that the flow directing portion 74 abuts against the slot proximal wall 68 so as to limit pivotal movements of the flow directing component 46 about the slot reinforcing member 70. The legs 78 and 80 are typically positioned radially inwardly and outwardly relatively to the slot reinforcing member 70 so that the apex 72 of the slot proximal wall 68 is received therebetween. This configuration ensures stability of the position of the flow directing component 46 when attached to the crown section 38.
Therefore, in this embodiment, the flow directing component 46 has a substantially key-hole shape cross-sectional configuration and is typically attachable to the crown section 38 and, more specifically, to the slot reinforcing member 70, by being substantially resiliently deformable so that the two legs 78 and 80 may be spread apart to insert the attachment portion 76 onto the slot reinforcing member 70. Typically, the flow directing component has a substantially uniform radial cross-sectional configuration along a circumferential direction, the terminology radial and circumferential being relative to the configuration of the substantially annular crown section 38.
To that effect, the flow directing component 46′ includes two flow directing portions 74 and 74′ and two attachment portions 76 and 76′. Also, the crown section 38′ defines a second slot reinforcing member 70′ extending substantially parallel to the first slot reinforcing member 70 in a substantially longitudinally spaced apart relationship relatively thereto. The alternative flow directing component may be broken at two different locations so as to optimize fluid flow at three different levels of wear of the crown section 38′.
The first attachment portion 76 and the first flow directing portion 74 are substantially similar to those present in the above-described flow directing component 46. The second attachment portion 76′ and the second flow directing portion 74′ are together substantially J-shaped in radial cross-sectional configuration, the terminology radial applying relatively to the annular configuration of the crown section 38′, and extend integrally substantially longitudinally from the first attachment portion 76. The second flow directing portion 74′ is therefore substantially plate-shaped and the second attachment portion 76′, which extends from the second flow directing portion 74′, is substantially arcuate. The second attachment portion 76′ is hooked around the second slot reinforcing member 70′. The second flow directing portion 74′ is detached from the first attachment portion 76 when frictional forces exerted thereonto become relatively large, which occurs typically when the crown section 38′ is worn down so that is extends longitudinally only minimally more than the second slot reinforcing component 70′. In some embodiments, this is facilitated by having a relatively weak junction between the first attachment portion 76 and the second flow directing portion 74′.
In
The flow directing portion 74″ is attached to the crown section 38″ through pins 86 that extend from legs 88, the legs 88 extending from the flow directing portion 74″. More specifically, two pairs of substantially longitudinally spaced apart legs 88 and corresponding pins 86 are provided, the two pairs of substantially longitudinally spaced apart pins 86 being circumferentially spaced apart from each other and each of the pins 86 being insertable into a respective one of the attachment recesses 82 for attaching the flow directing component 46″ to the crown section 38″. Having pairs of substantially longitudinally spaced apart pins 86 that are themselves circumferentially spaced apart provides four anchor points distributed along a rectangle, which provides stability to the attachment of the flow directing component 46″ to the crown section 38″.
The first plate 84 is abutting against the slot proximal wall 68 to further stabilize the flow directing component 46″ against pressures exerted by the fluid 28 when the fluid 28 is injected inside the drill bit 26 in which the flow directing component 46″ is provided. In some embodiments of the invention, the pins 86 are each provided at the end of a substantially radially extending leg 88 extending from the flow directing portion 74″, the legs 88 extending substantially radially and the pins 86 extending substantially circumferentially from the legs 88, all orientations being once again described with respect to the annular configuration of the crown section 38″. In this configuration, having legs 88 that are substantially resiliently deformable facilitates the insertion of the pins 86 inside the attachment recesses 82.
In some embodiments of the invention, the flow directing component 46″ is not removably attachable to the crown section 38 but is instead integrally formed into the slot 58″, but is otherwise shaped similarly to the above-described flow directing component 46″. In these embodiments, having pins 86 that extend integrally from the slot lateral walls 65 and 66 and that are relatively weak facilitates relatively easily breaking of these pins 86 when the predetermined wear threshold is reached.
In yet other embodiments of the invention, as seen in
In all of the above described embodiments, as drilling is performed, the crown section 38 wears down until the flow directing component 46 is exposed to reaction forces caused by the drilling process. These forces cause the flow directing component 46 to either detach of self-destroy so as to allow fluid 28 to go through the section of the slot 58 that was previously occupied by the flow directing portion 74. Therefore, a relatively constant flow of the fluid is directed towards the crown distal end 40, which is exposed to relatively large frictional forces when drilling is performed, and is therefore at risk of overheating or being unduly worn down by abrasion with debris.
Although the present invention has been described hereinabove by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims.
The present application is a National Stage Entry of PCT Application Serial Number PCT/CA2008/001639 filed on Sep. 5, 2008, which application claims priority from United States Provisional Patent Application Serial Number 60/935,872 filed on Sep. 5, 2007.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CA2008/001639 | 9/5/2008 | WO | 00 | 3/3/2010 |
Publishing Document | Publishing Date | Country | Kind |
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WO2009/030052 | 3/12/2009 | WO | A |
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