AU2010200074B2 - Core orientation device - Google Patents

Abstract

A core orientation device for indicating the orientation of a core drilled in a bore angled with respect to the vertical and received in a core receiving tube. The core orientation device includes: a body defining a body proximal portion, a substantially opposed body distal portion and a body longitudinal axis extending therebetween, the body distal portion including a tube attachment for attaching the core receiving tube thereto; a pair of channel delimiting elements the channel delimiting elements being mounted to the body between the body proximal and distal portions, the channel delimiting elements extending in a substantially parallel and spaced apart relationship relatively to each other, the channel delimiting elements defining a substantially circumferential and substantially annular channel therebetween; an indicator provided in the channel between the channel delimiting elements. The channel delimiting elements are movable between a locking position and an unlocking position, wherein in the locking position, the channel delimiting elements are closer to each other than in the unlocking position and engage the indicator to substantially prevent movements of the indicator in the channel, and, in the unlocking position, the channel delimiting elements are sufficiently spaced apart from each other to allow circumferential movements of the indicator along the channel. The channel delimiting elements are biased toward the locking position and operatively coupled to the body so that the channel delimiting elements are moved to the unlocking position when the body proximal and distal portions are biased toward each other.

Description

1 TITLE OF THE INVENTION Core orientation device. FIELD OF THE INVENTION [0001] This invention relates to core sample orientation. More particularly, the invention relates to an orientation device for providing an indication of the orientation of a core sample relative to a body of material from which the core has been extracted. BACKGROUND [0002] Core samples are obtained through core drilling operations. Core drilling is typically conducted with a core drill comprising outer and inner, or core receiving, tube assemblies. A cutting head is attached to the outer tube assembly, so that rotational torque applied to the outer tube assembly is transmitted to the cutting head..A core is-generated during the drilling operation, with the core progressively extending along the inner tube assembly as drilling progresses. When a core sample is acquired, the core within the inner tube assembly is fractured. The inner tube assembly and the fractured core sample contained therein are then retrieved from within the drill hole, typically by way of a retrieval cable lowered down the drill hole. Once the inner tube assembly has been brought to ground surface, the core sample can be removed and subjected to analysis. [0003] Typically, the core drilling operation is performed at an angle to the vertical, and it is desirable for analysis purposes to have an indication of the orientation of the core sample relative to the ground from which it was extracted. It is therefore important that there be some means of identifying the orientation that 2 the core sample had within the ground prior to it having been brought to the surface. [0004] Core orientation devices are used to provide an indication of the orientation of the core sample. One common way of obtaining an indication of the orientation of a core sample is through use of an orientation spear comprising a marker (such as a crayon) projecting from one end of a thin steel shank, the other end of which is attached to a wire line. [0005] The orientation spear is lowered down the drill hole, prior to the inner tube assembly being introduced. The marker on the orientation spear strikes the facing surface of material from which the core is to be generated, leaving a mark thereon. Because of gravity, the mark is on the lower side of the drill hole. The inner tube assembly is then introduced into the outer tube assembly in the drill hole. As drilling proceeds, a core sample is generated within the inner tube assembly. The core sample so generated carries the mark which was previously applied. Upon completion of the core drilling run and retrieval of the core sample, the mark provides an indication of the orientation of the core sample at the time it was in the ground. However, this method is relatively time-consuming an relatively imprecise. [0006] There are also mechanical core orientation devices for marking a core sample prior to its extraction from the drill hole. Typically, mechanical devices are adapted to be incorporated in the inner tube assembly for marking the core. For example, these mechanical devices include relatively soft pieces of material that are marked by a circumferentially movable weight when the core has filled the sampling tube, just prior to retrieving the core. This method requires the replacement of the soft pieces of material each time that the core orientation 3 device is used. [0007] Other types of core orientation device use electronic components to sense the orientation of the core. Due to their complexity, these devices are relatively expensive. [0008] Against this background, there exists a need in the industry to provide an improved core orientation device. [0009] An object of the present invention is therefore to provide an improved core orientation device. SUMMARY OF THE INVENTION [0010] in a broad aspect, the invention provides a core orientation device for indicating the orientation of a core drilled in a bore angled with respect to the vertical and received in a core - receiving tube. The core orientation device includes: a body defining a body proximal portion, a substantially opposed body distal portion and a body longitudinal axis extending therebetween, the body distal portion including a tube attachment for attaching the core receiving tube thereto; a first channel delimiting element and a second channel delimiting element; the first and second channel delimiting elements being mounted to the body between the body proximal and distal portions, the first and second channel delimiting elements extending in a substantially parallel and spaced apart relationship relatively to each other, the first and second channel delimiting elements defining a substantially circumferential and substantially annular channel therebetween: an indicator provided in the channel between the first and second channel delimiting elements. The first and second channel delimiting elements are movable between 4 a locking position and an unlocking position, wherein in the locking position, the first and second channel delimiting elements are closer to each other than in the unlocking position and engage the indicator to substantially prevent movements of the indicator in the channel, and, in the unlocking position, the first and second channel delimiting elements are sufficiently spaced apart from each other to allow circumferential movements of the indicator along the channel. The first and second channel delimiting elements are biased toward the locking position and operatively coupled to the body so that the first and second channel delimiting elements are moved to the unlocking position when the body proximal and distal portions are biased toward each other. Drilling the core in the bore with the core receiving tube attached to the tube attachment and the core receiving tube inserted in a hollow drill bit exerts a force on the body distal portion when the core is inserted in the core receiving tube, the force biasing the body proximal and distal portions toward each other, thereby moving the first and second channel delimiting elements in the unlocking position and allowing movement of the indicator in the channel under the action of gravity, and withdrawing the core receiving tube from the bore removes the force and causes the first and second channel delimiting elements to move in the locking position and stop movements of the indicator in the channel, thereby indicating the orientation of the core with respect of the bore by indicating the orientation of the core orientation device in the bore when drilling is stopped. [0011] In a preferred embodiment of the present invention, a core orientation device for indicating the orientation of a core drilled in a bore angled with respect to the vertical and received In a core receiving tube is provided, said core orientation device comprising: - a body defining a body proximal portion, a substantially opposed body distal portion and a body longitudinal axis extending therebetween, said 5 body distal portion including a tube attachment for attaching said core receiving tube thereto; a first channel delimiting element and a second channel delimiting element, said first and second channel delimiting elements being mounted to said body between said body proximal and distal portions, said first and second channel delimiting elements extending in a substantially parallel and spaced apart relationship relatively to each other, said first and second channel delimiting elements defining a substantially circumferential and substantially annular channel therebetween; and an indicator provided in said channel between said first and second channel delimiting elements; said first and second channel delimiting elements being movable between a locking position and an unlocking position, wherein in said locking position, said first and second channel delimiting elements are closer to each other than in said unlocking position and engage said indicator to substantially prevent movements of said indicator in said channel, and, in said unlocking position, said first and second channel delimiting elements are sufficiently spaced apart from each other to allow circumferential movements of said indicator along said channel; - wherein said first and second channel delimiting elements are biased toward said locking position and operatively coupled to said body so that said first and second channel delimiting elements are moved to said unlocking position when said body proximal and distal portions are biased toward each other; whereby drilling said core in said bore with said core receiving tube attached to said tube attachment and said core receiving tube inserted in a hollow drill bit exerts a force on said body distal portion when said 6 core is inserted in said core receiving tube, said force biasing said body proximal and distal portions toward each other, thereby moving said first and second channel delimiting elements in said unlocking position and allowing movement of said indicator in said channel under the action of gravity, and withdrawing said core receiving tube from said bore removes said force and causes said first and second channel delimiting elements to move in said locking position and stop movements of said indicator in said channel, thereby indicating the orientation of said core with respect of said bore by indicating the orientation of said core orientation device in said bore when drilling is stopped. [0012] Advantageously, the proposed core orientation device is relatively easy to use and relatively accurate in indicating the orientation of the core. Also, as opposed to many existing core orientation devices, unlocking of the Indicator occurs automatically and rapidly when the core is drilled, through forces naturally generated during the drilling process, and locking of the indicator occurs automatically and rapidly when retrieval of the core is started, at the distal end of the bore. These operations do not require any intervention from the intended user of the proposed core orientation device and are performed using a robust mechanism that ensures accuracy and precision in the determination of the orientation of the core. [0013] Also, the proposed core orientation device is relatively easily manufacturable at a relatively low cost using known components and methods. [0014] Furthermore, the proposed core orientation device is relatively robust and 7 is therefore at relatively low risk of being damaged during operation. [0015] 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 [0016] In the appended drawings: [0017] Figure 1, in a side elevation view, illustrates a core orientation device in accordance with an embodiment of the present invention, the core orientation device being shown attached to a core receiving tube and to a head assembly; (0018] Figure 2, in a side elevation view, illustrates the core orientation device shown in Figure 1; [0019] Figure 3, in a side elevation view, illustrates the distal end section of the core receiving tube shown in Figure 1; [0020] Figure 4, in a side cross-section view, illustrates the core orientation device shown in Figures 1 and 2, the core orientation device being shown in a retracted configuration; [0021] Figure 5, in a side cross-section view, illustrates the core orientation device shown in Figures 1, 2 and 4, the core orientation device being shown in an 8 extended configuration; [0022] Figure 6, in a top cross-section view along the line VI-VI of Fig. 5, illustrates the core orientation device shown in Figures 1, 2, 4 and 5; [0023] Figure 7, in a side cross-section view, illustrates a core orientation device in accordance with an alternative embodiment of the invention, the core orientation device being shown in a retracted configuration; [0024] Figure 8, in a side cross-section view, illustrates the core orientation device shown in Figure 7, the core orientation device being shown in an extended configuration; [0025] Figure 9, in a top cross-section view along the line IX-IX of Figure 8, illustrates the core orientation device shown in Figures 7 and 8; [0026] Figure 10, in a perspective view, illustrates a core orientation device in accordance with another alternative embodiment of the invention; (0027] Figure 11, in a side cross-section view, illustrates a core orientation device shown in Figure 10, the core orientation device, being shown in a retracted configuration; and (0028] Figure 12, in a side cross-section view, illustrates the core orientation device shown in Figures 10 and 11, the core orientation device being shown in an extended configuration.

9 DETAILED DESCRIPTION [0029] Referring to Figure 2, there is shown a core orientation device 10 in accordance with an embodiment of the present invention. As seen in Figure 1, the core orientation device 10 is usable for indicating the orientation of a core 12 drilled in a bore angled with respect to the vertical (not shown in the drawings) and received in the core receiving passageway 14 of a core receiving tube 16 usable for receiving the core 12. When used, the core receiving tube 16 is inserted through a hollow drill bit (not shown in the drawings) and receives the core 12 as the drill bit drills through surrounding materials in the bore. [0030] Typically, as seen in Fig. 3, the core receiving tube 16 defines a marker 20 for marking the core 12 as the core 12 enters the core receiving tube 16. For example, the marker 20 takes the form of a piece of relatively hard material protruding substantially radially Inwardly Into the core receiving passageway 14 substantially adjacent to the receiving tube distal end 18. In some embodiments of the invention, the marker 20 extends from a portion of the core receiving tube 16 that is detachable from the remainder of the core receiving tube 16. In alternative embodiments of the invention, the marker 20 is omitted as the core 12 and core orientation device 10 remain fixed with respect to each other as the core 12 is withdrawn from the bore. [0031] Returning to Fig. 1, the core orientation device 10 is attachable to the core receiving tube 16 and to a conventional head assembly 21 usable for retrieving the core 12, core receiving tube 16 and core orientation device 10 from the bore. The core orientation device 10 includes a body 19, the body 19 including an orientation device proximal portion 22 and an orientation device distal portion 24. As seen in Figs. 5 and 6, the orientation device proximal and distal portion 22 and 24 define 10 respectively a body proximal portion 26 and a body distal portion 28 substantially opposed to the body proximal portion 26, which themselves define respectively a head assembly attachment 30 and a tube attachment 32 for respectively attaching the head assembly 21 and the core receiving tube 16 thereto. For examples, the head assembly attachment 30 and tube attachment 32 take the form of threads able to engage complementary threads provided on the head assembly 21 and core receiving tube 16. A body longitudinal axis 23 extend between the body distal and proximal portions 28 and 26. (0032] The orientation device proximal and distal portions 22 and 24 together define a substantially circumferential and substantially annular channel 34. An indicator 36 is provided inside the channel 34. As seen in Figures 4, 5 and 6, the indicator 36 includes a substantially cylindrical indicating element 37 and extends substantially parallel to the body longitudinal axis 23. [0033] To define the channel 34, a first and a second channel delimiting elements 76 and 50 are mounted to the body 19 between the body proximal and distal portions 26 and 28. The first and second channel delimiting elements 76 and 50 extend in a substantially parallel and spaced apart relationship relatively to each other and define the channel 34 therebetween. The indicator 36 is provided in the channel 34 between the first and second channel delimiting elements 76 and 50. [0034] The first and second channel delimiting elements 76 and 50 are movable between a locking position (seen in Fig. 4) and an unlocking position (seen in Fig. 5). In the locking position, the first and second channel delimiting elements 76 and 50 are closer to each other than in the unlocking position and engage the indicator 36 to substantially prevent movements of the indicator 36 in the channel 34. In the 11 unlocking position, the first and second channel delimiting elements 76 and 50 are sufficiently spaced apart from each other to allow circumferential movements of the indicator 36 along the channel 34. [0035] As described in further details hereinbelow, the first and second channel delimiting elements 76 and 50 are biased toward the locking position and operatively coupled to the body 19 so that the first and second channel delimiting elements 76 and 50 are moved to the unlocking position when the body proximal and distal portions 26 and 28 are biased toward each other. [0036] In use, drilling the core 12 in the bore with the core receiving tube 16 attached to the tube attachment 32 and the core receiving tube 16 inserted in a hollow drill bit exerts a force on the core receiving tube 16 that is transmitted to the tube attachment 32 and biases the body proximal and distal portions 26 and 28 toward each other when drilling is completed. In turn, this moves the first and second channel delimiting elements 76 and 50 in the unlocking position and allow movement of the indicator 36 in the channel 34 under the action of gravity. Withdrawing the core receiving tube 16 from the bore removes the force and causes the first and second channel delimiting elements 76 and 50 to move in the locking position and stop movements of the indicator in the channel, thereby indicating the orientation of the core with respect of the bore by indicating the orientation of the core orientation device 10 in the bore when drilling is stopped. [0037] The orientation device proximal and distal portions 22 and 24, and therefore the body proximal and distal portions 26 and 28, are movable substantially longitudinally relatively to each other. The body 19 is movable between an extended configuration (shown in Fig. 4) and a retracted configuration 12 (shown in Fig. 5). The body proximal and distal portions 26 and 28 are closer to each other in the retracted configuration than in the extended configuration. The indicator 36 is substantially circumferentially movable inside the circumferential channel 34 relatively to the orientation device proximal and distal portions 22 and 24 when the core orientation device 10 is in the retracted configuration. The indicator 36 is substantially fixed in the circumferential channel 34 relatively to the orientation device proximal and distal portions 22 and 24 when the core orientation device 10 is in the extended configuration. In other words, the first and second channel delimiting elements 76 and 50 are in the unlocking position when the body 19 is in the retracted configuration and the first and second channel delimiting elements 76 and 50 are in the locking position when when the body 19 is in the extended configuration. [0038] The core orientation device 10 is now -described in further details with reference to Figures 4 and 5. The orientation device distal portion 24 includes a distal base 38 and defines a distal body recess 40. A distal shaft 42 extends from the distal base 38 along and inside the distal body recess 40. Typically, a recess 45 extends substantially longitudinally in the distal base 38 for receiving a portion of the distal shaft 42. This allows disassembly of the core orientation device 10 by removing suitable parts thereof to allow longitudinal movements of the components of the core orientation device 10 relatively to each other. Many combinations for allowing such disassembly are possible and well within the scope of the person of ordinary skill in the art. This aspect will therefore not be described in further details. Also, in some embodiments of the invention, the core orientation device 10 cannot be disassembled and is permanently assembled at the time of manufacturing. [0039] More specifically, the distal base 38 defines a distal body end wall 46 13 located substantially adjacent to the tube attachment 32 and a distal body peripheral wall 44 extends substantially longitudinally from the distal body end wall 46 toward the orientation device proximal portion 22, the distal body peripheral wall 44 and distal body end wall 46 together defining the distal body recess 40. The distal body peripheral wall 44 is typically substantially transparent, to allow visualization of the position of the indicating element 37 in the channel 34. The second channel delimiting element 50 takes the form of a flange that extends substantially radially inwardly into the distal body recess 40 from the distal body peripheral wall 44 substantially opposed to the distal body end wall 46. The second channel delimiting element 50 is therefore fixed with respect to the body distal portion 28. The second channel delimiting element 50 defines a distal body aperture 51 leading into the distal body recess 40. [0040] The distal shaft 42 defines a distal shaft proximal end 52 and a substantially opposed distal shaft distal end 54. The distal shaft 42 extends-from the distal body end wall 46 substantially adjacent to the distal shaft distal end 54. The distal shaft proximal end 52 protrudes from the distal body recess 40 and defines a distal shaft flange 56 extending substantially radially outwardly from the distal shaft 42 substantially adjacent to the distal shaft proximal end 52. In some embodiments of the invention, the distal shaft flange 56 is removable from the distal shaft 42 for facilitating disassembly of the core orientation device 10. [0041] A pair of mobile collars 58 and proximal and distal biasing elements 60 and 62 are mounted in the distal body recess 40, as described in further details hereinbelow. The mobile collars 58 and proximal and distal biasing elements 60 and 62 are substantially annular. For example, the proximal and distal biasing elements 60 and 62 are made of a substantially resiliently deformable material, such as rubber.

14 [0042] In some embodiments of the invention, a sleeve 64 is mounted to the distal body peripheral wall 44 so as to be rotatable thereabout. The sleeve 64 defines a window 66 positionable substantially in register with the indicator 36. As seen in Fig. 2, indicia 68 are inscribed on the sleeve 64 and a reference mark 70 is indicated on the distal body peripheral wall 44 substantially adjacent to the indicia 68. The indicia are indicative of a position of the window 66 relatively to the reference mark 70, which itself indicates an angle between the reference mark 70 and the marker 20. In some embodiments of the invention, the indicia 68 are arbitrary and are useful only to indicate that the indicator 36 was moved when a core 12 was retrieved. (0043] The orientation device proximal portion 22 includes a proximal base 72 and a proximal shaft 74. The proximal base 72 defines a proximal base end wall 80 and a proximal body peripheral wall 78 extending therefrom. The proximal body peripheral wall 78 extends away from the orientation device distal portion 24. The proximal shaft 74 extends substantially opposed to the proximal body peripheral wall 78 from the proximal base end wall 80 towards the orientation device distal portion 24. [004] The first channel delimiting element 76 takes the form of a fixed collar extending substantially radially outwardly from the proximal shaft 74 substantially opposed to the proximal base end wall 80. The first channel delimiting element 76 is therefore fixed with respect to the body proximal portion 26. The first channel delimiting element 76 defines a collar distal end surface 86 and a substantially opposed collar proximal end surface 88. The proximal shaft 74 defines a substantially longitudinally extending proximal shaft passageway 84 extending substantially longitudinally therethrough. The proximal shaft passageway 84 leads into a proximal body end wall aperture 82 that extends through the proximal base 15 end wall 80. [0045] The distal shaft 42 is slidably mounted into the proximal shaft passageway 84 so as to protrude from the proximal body end wall aperture 82 and be substantially longitudinally movable relatively ot the proximal shaft 74. Therefore, the proximal shaft 74, distal shaft 42 and distal body peripheral wall 44 are substantially .coaxial...The.. dl.stal .shaft flange 56 .extends..radally. over .. a larger distance than the proximal body end wall aperture 82, thereby preventing removal of the distal shaft 42 from the proximal shaft passageway 84. The proximal shaft 74 is mounted in the distal body recess 40 through the distal body aperture 51 and fits substantially snugly into the distal body aperture 51. [0046] The mobile collars 58 are part of the indicator 36 and mounted to the proximal shaft 74 so as to be substantially longitudinally movable therealong. The mobile collars 58 are substantially longitudinally spaced apart from each other and receive the indicating element 37 therebetween. The proximal biasing element 60 is mounted on the proximal shaft 74 between the proximalmost mobile collar 58 and the second channel delimiting element 50. The distal biasing element 62 is mounted on the distal shaft 42 between the distal body end wall 46 and the first channel delimiting element 76 and is provided for biasing the first channel delimiting element 76 and the body distal portion 28 away from each other. [0047] In the extended configuration, as shown in Figure 5, the indicator 36 is substantially fixed is the circumferential channel 34. Indeed, in the extended configuration, the proximal biasing element 60 and the first channel delimiting element 76 bias the mobile collars 58 toward each other. The first and second channel delimiting elements 76 and 50, through the mobile collars 58, therefore 16 frictionally engage the indicator 36 because the first and second channel delimiting elements 76 and 50 are mounted around the proximal and distal shafts 74 and 42 so as to be fixed respectively relatively to the body proximal and distal portions 26 and 28 with the first channel delimiting element 76 being provided between the second channel delimiting element 50 and the body distal portion 28 and the second channel delimiting element 50 being provided between the first channel delimiting element 76 and the body proximal portion 26. [0048] In the retracted configuration, as shown in Figure 4, the proximal biasing element 60 is moved away from the first channel delimiting element 76 as compared to the extended configuration. This removes the bias on the mobile collars 58 and allows free movement of the indicator 36 in the circumferential channel 34. This movement of the proximal biasing element 60 away from the first channel delimiting element 76 is permitted by a deformation of the distal biasing element 62. [0049] In some embodiments of the invention, a screw 93 is removably insertable in a threaded screw aperture 95 extending substantially radially inwardly through the proximal base end wall 80 up to the proximal body end wall aperture 82, and a substantially longitudinal groove 91 is formed in the distal shaft 42. The groove 91 is substantially in register with the screw aperture 95. When the screw 93 is fully inserted in the screw aperture 95, the distal shaft 42 is prevented from begin removed from the proximal body end wall aperture 82 by the interaction between the screw 93 and the groove 91. When the screw 93 is removed from the screw aperture 95, this interaction disappears to allow disassembly of the core orientation device 10. In some embodiments of the invention, this disassembly also requires other steps.

17 (0050] In use, the core orientation device 10 is attached to the core receiving tube 16 and to the head assembly 21. Afterwards, the assembly thereby formed is lowered in a bore in which a conventional hollow drill bit has been positioned in a conventional manner. In this default state, the core orientation device 10 is in the extended configuration as gravitational forces pull onto the orientation device distal portion 24. As the core 12 is moved inside the core receiving tube 16, the marker 20 inscribes a mark on the outer surface of the core 12. [0051] When the core 12 fills out the core receiving tube 16, a force is exerted onto the orientation device distal portion 24 by the core 12, which moves the orientation device distal portion 24 towards the orientation device proximal portion 22, thereby configuring the core orientation device 10 into the retracted configuration. Since the bore from which the core 12 is obtained is typically not completely vertical, in the retracted configuration, the indicating element 37 achieves the lowest position possible inside the circumferential channel 34 under the action of gravity. When the pressure exerted by the core 12 is removed as the head assembly 21 is retracted from the bore and pulls on the orientation device proximal portion 22, the core orientation device 10 returns to the extended configuration and the indicator 36 remains fixed inside the circumferential channel 34. [0052] Therefore, the orientation of the core 12 is marked as withdrawal of the core 12 is performed. Rotating the window 66 until it is substantially in register with the indicator 36 allows for a determination of the orientation of the core 12 by noting which of the indicia 68 is substantially aligned with the reference mark 70. [0053] As seen in Figures 7 to 9, in an alternative embodiment of the intervention, 18 an alternative core orientation device 10' is provided in which the indicating element 37' is substantially spherical. Also, as seen in Figs. 7 to 9, the Indicator 36 includes at least two indicating elements 37', for example three indicating elements 37', mounted in the channel 34 in substantially longitudinally spaced apart relationships relative to each other and a predetermined number of separators 58', the predetermined number being one less than a number of the indicating elements 37'. Each of the separators 58 takes the form of a collar mounted between a respective pair of adjacent indicating elements 37', the separators dividing the channel 34 into sub-channels 39 having each a substantially annular configuration. The separators 58' are substantially freely longitudinally movable in the channel 34. This configuration brings robustness to the orientation determination as blockage of one of the indicating elements 37' does not result in an inaccurate reading as the other indicating elements 37' can indicate the proper orientation of the core 12. Otherwise, the core orientation device 10' works substantially similarly to the core orientation device 10. [0054] Figures 10 to 12 illustrate another alternative core orientation device 10", in which many elements also present in the core orientation devices 10 and 10' are not identified for clarity reasons. As seen in Figures 11 and 12, the proximal biasing element 60 is omitted from the core orientation device 10 and the distal biasing element 62" takes the form of stacked Belleville washers 61. The spacers 58" are separated from each other by biasing elements 59 that bias the spacers 58" away from each other. Also, each of the spacers 58" includes a substantially cylindrical spacer body 100 mounted to the proximal shaft 74" and a substantailly radially outwardly extending flange 102, the indicating elements 37', which are substatially spherical, being mounted between adjacent flanges 102. [0055] Also, mounting apertures 104, 106 and 108 extend respectively 19 substantially diametrically through the distal shaft 42" and the distal base 38, through the second channel delimiting element 50, proximal shaft 74" and distal shaft 42", and through the distal shaft 42", proximal shaft 74" and proximal base 72. Each of the mounting apertures 104, 106 and 108 receives a respective pin 110, 112 and 114 extending therethrough. The pins 110, 112 and 114 prevent the various components from sliding out of each other. In some embodiments, the pins 110, 112 and 114 are removably insertable through the mounting apertures 104, 106 and 108 for allowing disassembly of the core orientation device 10" for maintenance purposes, for example. When the pins 110, 112 and 114 are removed from the mounting apertures 104, 106 and 108, the various components of the core orientation device 10" can be disassembled by moving them longitudinally relatively to each other. [0056] The proximal shaft 74" is provided with an aperture 75 provided substantially in register with the mounting aperture 106 and having a longitudinal dimension greater than the mounting aperture 106 for allowing relative movements of the proximal and distal shafts 74 and 42. Similarly, the distal shaft 42 is provided with an aperture 43 provided substantially in register with the mounting aperture 108 and having a longitudinal dimension greater than the mounting aperture 108 for allowing relative movements of the proximal and distal shafts 74 and 42. Otherwise, the core orientation device 10" works substantially similarly to the core orientation device 10' and will not be described in further details. [0057] 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.

20 [0058] In the specification the terms "comprising" and "containing" shall be understood to have a broad meaning similar to the term "including" and will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. This definition also applies to variations on the terms "comprising" and "containing" such as comprisee, "comprises"-, "contain" and "contains".

Claims (16)

1. A core orientation device for indicating the orientation of a core drilled in a bore angled with respect to the vertical and received in a core receiving tube, said core orientation device comprising: - a body defining a body proximal portion, a substantially opposed body distal portion and a body longitudinal axis extending therebetween, said body distal portion including a tube attachment for attaching said core receiving tube thereto; - a first channel delimiting element and a second channel delimiting element, said first and second channel delimiting elements being mounted to said body between said body proximal and distal portions, said first and second channel delimiting elements extending in a substantially parallel and spaced apart relationship relatively to each other, said first and second channel delimiting elements defining a substantially circumferential and substantially annular channel therebetween; and - an indicator provided in said channel between said first and second channel delimiting elements; - said first and second channel delimiting elements being movable between a locking position and an unlocking position, wherein in said locking position, said first and second channel delimiting elements are closer to each other than in said unlocking position and engage said indicator to substantially prevent movements of said indicator in said channel, and, in said unlocking position, said first and second channel delimiting elements are sufficiently spaced apart from each other to allow circumferential movements of said indicator along said channel; - wherein said first and second channel delimiting elements are biased 22 toward said locking position and operatively coupled to said body so that said first and second channel delimiting elements are moved to said unlocking position when said body proximal and distal portions are biased toward each other; whereby drilling said core in said bore with said core receiving tube attached to said tube attachment and said core receiving tube inserted in a hollow drill bit exerts a force on said body distal portion when said core is inserted in said core receiving tube, said force biasing said body proximal and distal portions toward each other, thereby moving said first and second channel delimiting elements in said unlocking position and allowing movement of said indicator in said channel under the action of gravity, and withdrawing said core receiving tube from said bore removes said force and causes said first and second channel delimiting elements to move in said locking position and stop movements of said indicator in said channel, thereby indicating the orientation of said core with respect of said bore by indicating the orientation of said core orientation device in said bore when drilling is stopped.

2. A core orientation device as defined in claim 1, wherein said body proximal and distal portions are movable substantially longitudinally relatively to each other, said body being movable between an extended configuration and a retracted configuration, said body proximal and distal portions being closer to each other in said retracted configuration than in said extended configuration; said first and second channel delimiting elements are in said unlocking position when said body is in said retracted configuration and said first and second channel delimiting elements are in said locking position when when said body is in said extended configuration. 23

3. A core orientation device as defined in claim 2, further comprising a proximal shaft extending from said body proximal portion toward said body distal portion and a distal shaft extending from said body distal portion toward said body proximal portion, said proximal and distal shaft being substantially coaxial relatively to each other and mounted to each other so as to be substantially longitudinally movable relatively to each other.

4. A core orientation device as defined in claim 3, wherein said first and second channel delimiting elements are mounted around said proximal and distal shafts so as to be fixed respectively relatively to said proximal and distal body portions, said first channel delimiting element being provided between said second channel delimiting element and said body distal portion and said second channel delimiting element being provided between said first channel delimiting element and said body proximal portion.

5. A core orientation device as defined in claim 4, further comprising a biasing element provided between said first channel delimiting element and said body distal portion for biasing said first channel delimiting element and said body distal portion away from each other.

6. A core orientation device as defined in claim 4, further comprising a peripheral wall extending substantially longitudinally from said body distal portion toward said body proximal portion, said peripheral wall being substantially coaxial with respect to said proximal and distal shafts, said proximal shaft being hollow and receiving said distal shaft thereinto. 24

7. A core orientation device as defined in claim 6, wherein said first channel delimiting element is fixedly mounted to said proximal shaft substantially opposed to said body proximal portion and said second channel delimiting element is fixedly mounted to said peripheral wall substantially opposed to said body distal portion.

8. A core orientation device as defined in claim 6, wherein said peripheral wall includes a sleeve rotatable about said body longitudinal axis, said sleeve defining a window positionable substantially in register with said indicator, and said core orientation device is provided with indicia for indicating an orientation of said window relatively to the remainder of said core orientation device.

9. A core orientation device as defined in claim 1, wherein said core orientation device is attachable to a head assembly for allowing retrieval of said core orientation device from said bore.

10. A core orientation device as defined in claim 1, wherein said indicator includes a substantially cylindrical indicating element substantially parallel to said body longitudinal axis.

11. A core orientation device as defined in claim 1, wherein said indicator includes a substantially spherical indicating element.

12. A core orientation device as defined in claim 1, wherein said indicator includes at least two indicating elements mounted in said channel in substantially longitudinally spaced apart relationships relative to each other and a predetermined number of separators, said predetermined 25 number being one less than a number of said indicating elements, each of said separators being mounted between a respective pair of adjacent indicating elements, said separators dividing said channel into sub channels having each a substantially annular configuration, said spacers being substantially freely longitudinally movable in said channel.

13. In combination, a core receiving tube and a core orientation device as defined in claim 1, said core receiving tube being attached to said tube attachment.

14. A combination as defined in claim 13, further comprising a marker for marking said core as said core enters said core receiving tube, said marker being positioned in a predetermined circumferential positional relationship relatively to said body proximal and distal portions.

15. A combination as defined in claim 14, wherein said marker protrudes radially inwardly into said core receiving tube.

16. A core orientation device as herein substantially described with reference to the accompanying drawings and/or description.