Background of the Invention Core sampling is typically employed to allow geological surveying of the ground for the purposes of exploration and/or mine development. Analysis of the material within the core sample provides information of the composition of the ground. In order to map, for example, a vein of ore it is necessary to also have knowledge of the orientation of the core sample relative to the surrounding ground from which it is cut.

The present inventor has developed an orientation device which provides an indication of the orientation of a core sample, and is described in International Publication No. WO 03/038232, the contents of which is incorporated herein by way of reference. The orientation device in the above-mentioned International publication comprises in broad terms, a face orientator and a bottom orientator supported on a shaft. The face orientator includes a number of pins similar to a VAN RUTH orientator, together with a marker such as a pencil for placing a physical mark on the face of a core being drilled. The core orientator comprises three balls each located within a corresponding race. The width of the races can be switched between a first width which allows the balls to roll about their races and second width in which the balls are clamped within their races.

The orientator is loaded in a core tube of a core drill and arranged to operate upon commencement of the drilling

of a core. Moreover, when the core drill to which the orientator device is fitted is initially brought into contact with the toe of the hole, the pins are pushed backwards to provide a profile of a surface of the toe, and the marker places a mark on the core. The width of the races is also switched to the second width resulting in the balls being clamped in their races. Prior to clamping the balls are able to run freely and therefore would ordinarily, by action of gravity, roll to the lowest point in their races which corresponds with the bottom of the hole being drilled.

The core being cut enters, and pushes the orientation device further inside, the core tube. Once the core sample has been cut the core tube is withdrawn from the core drill. The core sample and orientation device are removed from the core tube. The orientation device is rotationally aligned with the face of the core sample by matching the location of the mark with the marker/pencil and profile of the face with the position of the pins. A line is then marked on the core in alignment with the balls. The line represents the bottom or lowest position in the hole. Thus by rotating the core so that the line is at the bottom of the core the core is orientated to the position in which it was disposed in the ground.

The orientation device has proved to be technically and more importantly commercially very successful being widely used by core drillers all over the world.

The present invention was developed as an enhancement of the orientation device described in International Publication No. WO 03/038232.

Summary of the Invention According to the present invention there is provided a core orientation device comprising:

a face orientator for forming a face mark on a face of a core being cut by a core drill; a bottom orientator providing an indicator of the location of a bottom of a hole from which said core is cut; and, a demountable disc supported in axial alignment with said face orientator, wherein said disc is marked with a first mark at a location rotationally aligned with said face mark and marked with a second mark in rotational alignment with said indicator to thereby provide a record of the orientation of said core.

Optionally said first mark is pre-formed on said disc and said face orientator comprises a face marker for forming said face mark, wherein said disc is orientated relative to said face orientator so that said first mark is rotationally aligned with said face marker.

Optionally said first mark comprises a notch formed in an outer peripheral edge of said disc.

Optionally said disc comprises a key and said core orientation device further comprises a recess or hole for receipt of said key, said key and said recess or hole juxtaposed so that when said key is located in said recess or hole said first mark is rotationally aligned with said face marker.

Optionally said recess or hole is formed in said face orientator and said disc is supported on said face orientator.

Optionally the key is formed on and protrudes upright from a radial face of the disc. In this embodiment the key also constitutes the first mark.

Optionally said disc comprises a side mark providing an indication of which side of said disc is facing said core while said core is being cut.

In one embodiment the key comprises the side mark.

Optionally said disc is clamped by and between said face orientator and said bottom orientator.

According to the invention there is also provided a recording device to record the orientation of a core cut from a material by a core drill having an orientation device comprising a face orientator and a bottom of hole orientator, the recording device comprising: a disc provided with a hole located to enable coupling of the disc to the orientation device.

The recording device may comprise a key extending from the disc to rotationally lock the recording device to the orientation device.

In one embodiment the key extends into the hole formed in a disc. However in an alternate embodiment the key extends upright from a radial face of the disc.

Optionally the recording device further comprises a pre- formed first mark located in a position to rotationally align with the face orientator. In one embodiment, the key constitutes the first mark.

According to the invention there is also provided a method for producing a record of the orientation of a core cut from a body of material by a core drill provided with a face orientator and a bottom orientator said method comprising:

demountably coupling a disc in axial alignment with said face orientator and said bottom orientator; marking said disc with a first mark in rotational alignment with said face mark; and, marking said disc with a second mark in rotational alignment with an indicator of said bottom orientator providing an indication of the location of the bottom of said hole.

Preferably marking said disc with said first mark comprises pre-forming the disc with the first mark deforming said disc.

The pre-forming may comprise at least one of cutting or stamping a notch or groove on the disc, or casting the disc with the first mark.

Marking said second mark may comprise physically marking said disc after said core has been withdrawn from said hole.

Marking the second mark may comprise marking said second mark with an indelible marker.

Brief Description of the Drawings Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is an exploded view of a core orientation device in accordance with an embodiment of the present invention; Figure 2 is a view of the core orientation device in an assembled state;

Figure 3 is a longitudinal section view of said core orientation device; Figure 4 is a perspective view of a disc incorporated in the core orientation device; Figure 5 shows the use of a disc incorporated in the disc placed on a protractor drawn on a card to provide an indication of the rotational orientation of the core; and, Figure 6 depicts the use of a protractor for the purposes of marking a cut core to provide an indication of the location of the bottom of the hole from which the core is cut; and, Figure 7 depicts a disc of a second embodiment of the core orientation device.

Detailed Description of Preferred Embodiment Referring to the accompanying drawings the core orientation device 10, which would typically be used with a core or diamond drill (not shown) comprises a face orientator 12 for forming a face mark 14 on a face 16 of a core 18 being cut by the drill; a bottom orientator 20 and a demountable disc 22. The bottom orientator includes an indicator, in the form of balls 24 which provide an indication of the location of the bottom of a hole from which the core 18 is cut. The face orientator 12, and disc 22 are co-axially aligned. The disc 22 is marked with a first mark 28 which is rotationally aligned with the face mark 14 formed on the core 18 by the face orientator 12. A marking C is placed on a front face of the disc 22 to ensure that it is placed with the correct face up when used to read an angle of inclination of a hole. When the disc 22 is loaded onto the device 10 the face marked C faces the core to be drilled. In this particular embodiment the first mark 28 is pre-formed on the outer

circumferential edge 29 of the disc 22 and is arranged in alignment with a marker pencil 30 of the face orientator 12. When the device 10 is withdrawn from a hole being drilled, a geologist or other qualified person can place a second mark 32 on the disc 22 in alignment with the balls 24 which, as will be explained in greater detail below, have been clamped in position providing an indication of the location of the bottom of the hole. Thus, the disc functions as a recording device providing a record of the orientation of the core 18.

Looking at the various components of the device 10 in greater detail, the face orientator 12 comprises a plurality of circumferentially arranged pins 34 which are retained in, and can slide axially of, a core block 36.

The pencil 30 is similarly arranged to be retained in and slide axially of the core block 36. The core block 36 is provided with a circumferential cut-out through which the pins 34 and pencil 30 extend, and which seat a plurality of rubber bands or 0-rings 38. The 0-rings 38 act as a brake holding the pencil 30 and pins 34 in position in the absence of a force applied along the length of the pencil 30 or pins 34. The core block 36 is provided with an axially depending boss 40 about which is formed a circular flange 42 in which is formed a locating notch 44. The notch 44 does not extend axially for the whole thickness of the flange 42.

The disc 22 is formed with a central hole (and thus takes the general form of a washer) and is provided with a small key or tab 46 which extends radially inward from an inner circumferential edge 48 of the disc 22 and is designed to seat in the notch 44.

With particular reference to Figure 3, the bottom orientator 20 includes an indicator in the form of a plurality of (in this instance three) balls 24a, 24b and 24c (hereinafter referred to in general as"balls 24")

disposed within respective races 50a, 50b and 50c (hereinafter referred to in general as"races 50"). The races are formed by three washers 52a, 52b and 52c (hereinafter referred to in general as"washers 52") and one side of a stop 54, through each of which the shaft 26 extends. The race 50a is defined between the washers 52a and 52b; the race 50b is defined between the washers 52b and 52c; and, the race 50c is defined between the washer 52c and the stop 54. Springs 55 are placed about the shaft 26 in each of the races 50 to hold the races 50 apart to the extent that the balls 24 can freely roll about their respective races in the absence of a force being applied to the shaft 26 moving it axially relative to the orientator 20.

The shaft 26 extends also through a mount portion 56 of the orientator 20. A transversely extending roll pin 57 couples the shaft 26 to the washer 52a. A further roll pin 59 extends transversely through the mount 56 into an axial keyway or slot 61 formed in the end of the shaft 26.

The roll pin 59 prevents axial rotation of the shaft 26 relative to the orientator 20, while allowing axial translation of the shaft 26 relative to the orientator 20.

A downhole end of the mount 56 is formed with a tubular spigot 63. The boss 40 of the face orientator 12 is screwed onto the spigot 63 with the disc 22 seated on the flange 42. This ensure co-axial alignment of the face orientator 12, disc 22 and bottom orientator 20.

A transparent sleeve 65 is coupled and extends between the stop 54 and mount portion 56 enclosing the washers 52 and ball 24. A volume of light oil is also sealed in the sleeve 65.

The shaft 26, bottom orientator 20, face orientator 12 and washer 22 are disposed within a trigger body 64 which extends into a back end 66 of the core orientator 10. The back end 66 in turn is composed of a latch body 68 and

anchor body 70. The trigger body 64 includes a detachable cylindrical shroud 72 which is of a length such that it can fully accommodate the bottom orientator 20 and face orientator 12. A downhole end 74 of the shroud 72 is tapered to a diameter less than that of the core 18 cut by the drill so that the core 18 can abut the end 74 but cannot enter the shroud 72.

The trigger body 64 includes a tubular portion 76 which extends rearwardly of the shroud 72 and axially into the latch body 68 and anchor body 70. The shaft 26 extends through the tubular portion 76 and has attached to it, at its uphole end 78, a trigger seat 80. A pair of trigger balls 82 are each seated partially in a circumferential groove 84 formed in the trigger seat 80 and holes 86 formed in the tubular portion 76. A spring 88 is disposed about the shaft 26 within the tubular portion 76 and is biased to act on the trigger seat 80 in a manner urging the shaft 26 to move in an uphole direction. A further spring 90 is disposed about the outside of a length of the tubular portion 76 extending through the latch body 68.

The spring 90 urges the trigger body in a downhole direction.

Latch dogs 92 are pivotally coupled by roll pins 94 to the latch body 68 and latch onto a downhole end of the core tube to initially prevent the device 10 from being pushed in an uphole direction through the core tube when the device 10 first contacts the toe of the hole being drilled. Latch dogs 92 seat on a latch seat 96 of a constant diameter formed about an outer circumferential surface of a length 98 of the tubular portion 76. Moving in a downhole direction from the length 98 a recess 100 is formed in the outer diameter of the tubular portion 76.

The anchor body 70 is screw coupled to the latch body 68 and seats about its outer diameter an anchor sleeve 102 which is able to move axially relative to the anchor body

70 between a shoulder 104 formed about the outer circumference of the anchor body 70 and an uphole end 106 of the latch body 68. A spring 108 disposed about the outside of the anchor body 70 urges the anchor sleeve 102 against the shoulder 104. Anchor balls 110 are retained in the anchor sleeve 102 but have a portion which extends radially from the anchor sleeve 102 when the anchor sleeve 102 is abutted against the shoulder 104. In this position the anchor balls 110 are held on a constant outer diameter portion 111 of the anchor body 70.

Moving in a downhole direction from the portion 111, the outer circumference of the anchor body 70 is formed with a tapered portion 113 leading to a circumferential recess 112. The anchor body 70 has a first length 114 at a downhole end having a constant inner diameter, a second length 116 of constant but increased inner diameter and an intervening tapered length 118 of progressively increasing inner diameter.

The operation of the orientation device 10 will now be described in detail.

The device 10 when initially inserted into a core tube is in essence in the configuration shown in enclosed Figure 3, with the pins 34 and pencil 30 extending from the downhole end 74 of the shroud 72, the spring 88 in a relatively compressed state, the spring 90 in a relatively extended state urging the trigger body 64 in a downhole direction, the spring 108 also in a relatively extended state urging the anchor body 102 against the shoulder 104, and the trigger balls 82 seated on the inner diameter of length 114 of the anchor body 70 thereby locking the shaft 26 to the trigger body 64. The disc 22 is seated on the flange 42 with tab 46 seated in the notch 44. The first mark 28 is aligned with the pencil 30 and the balls 24 are able to fully rotate about the shaft 26 within their respective races 50.

The device 10 is loaded into a downhole end of the core tube by first inserting the anchor body 70. Eventually the latch dogs 92 abut the downhole end of the core tube preventing further insertion of the device 10. During the insertion, the anchor body 102 slides axially away from the shoulder 104 so that the balls 110 eventually roll along tapered portion 113 of the anchor body 70 and thus effectively move radially inward. In this position, the balls 110 can roll up the inner diameter of the core tube allowing the device 10 to be inserted into the core tube.

Once the insertion has ceased by the abutment of the latch dogs 92 with the end of the core tube, the spring 108 urges the sleeve 102 in an uphole direction causing the balls 110 to commence to ride up the tapered length 113 toward length 111 to a position where they bear against the inner diameter of the core tube. This effectively locks the device 10 to the core tube preventing it from falling out. Indeed, it should be appreciated that any force applied to the device 10 in a downhole direction further wedges the balls 110 against the inner diameter of the core tube increasing its grip.

The core tube is then lowered into a core drill via a conventional wire line, with the core drill being suspended above the toe of the hole to be drilled. With the core tube correctly seated within the core drill, the end of the shroud 74 together with the free ends of the pencil 30 and pins 34 extend axially beyond and through a core bit attached to the core drill. When the drill is lowered onto a toe of the hole, the pencil 30 will eventually contact the face 16 of the core to be drilled forming the first mark 14. Additionally, the pins 34 contact the face 16 and slide axially in the uphole direction to positions which will correspond with the profile of the face 16. The balls 24 also rotate within their races 50 and, due to gravity, will align with the lowest point within their respective races.

As the core drill is further lowered prior to the commencement of drilling, the shroud end 74 will eventually be brought into contact with the toe of the hole. Now, further lowering of the core drill results in the trigger body 64 moving in an uphole direction relative to the back end 66 which remains fixed to the core tube.

Thus, the tubular portion 76 commences to slide axially relative to the latch body 68 compressing the spring 90.

Eventually, the trigger balls 82 will roll onto the tapered portion 118 and second portion 116 of the anchor body 70. When this occurs, the trigger balls 82 are able to move outwards in a radial direction disengaging from the groove 84 in the trigger seat 80. This releases a spring 88 allowing it to push the trigger seat 80 and thus the shaft 26 in the uphole direction relative to the trigger body 64. This in turn pulls the washer 52a toward the stop 54 compressing the springs 55 and clamping the balls 24 within their respective races.

Continued lowering of the core drill onto the toe of the hole results in the latch dogs 92 sliding off their seat 96 into the recess 100. The latch dogs 92 are now free to rotate inwardly thereby disengaging the device 10 from the core tube.

As drilling commences, the core 18 is cut and advances into the core tube pushing the entire device 10 inwardly of the core tube.

Once drilling has ceased and the core has been broken, the core tube with the device 10 and the core sample is retrieved by conventional wireline. The device 10 together with the core sample are removed from the core tube and the shroud 72 detached. The device 10 and the core sample are rotationally aligned by either matching the profile of the pins 34 to the profile of the face 16 or the position of the pencil 30 with the first mark 14.

It should be appreciated that individually matching either

the pencil 30 with the marking 14 or the orientation of the pins 34 with the profile of the face 16 will provide rotational alignment of the device 10 with the core sample 18. Thereafter, a geologist or other operator can mark the disc 22 with the second mark 32 in rotational alignment with the clamped balls 24, which can be viewed through the transparent sleeve 65. At the same time a mark, typically a line, is drawn on the outer circumferential surface of the core in alignment with the balls 24. The mark 32 together with the marking made on the core denotes the position of the bottom of the hole from which the core 18 was cut.

The disc 22 can now be removed from the device 10 by unscrewing the face orientator 12. The disc 22 provides a permanent record of the orientation of the core as the first mark 28 provides an indication of the rotational orientation of the core 18 while the second mark 32 provides an indication of the position of the bottom of the hole.

In order to ensure that the core 18 has been correctly marked, a geologist or other operator may place the disc 22 against a card 120 (refer to Figure 5) on which is drawn a protractor 122 with the first mark 28 aligned with the 0° position of the protractor 122 and with the face marked C facing up. The position of the second mark 32 can then be read from the protractor. In their particular embodiment, marking 32 is at a position of 46° clockwise of the first mark 28. The geologist may then place an annular protractor 124 on the outside of the core 18 with the 0° position in radial alignment with the marking 14 and then confirm that the marking placed on the outer circumferential surface of the core along with the balls 24 is at the 46° position. This provides a basis for checking the markings on the core 18.

Now that an embodiment of the invention has been described in detail it will be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive concepts. Most notably, it will be recognised that the present invention is not limited to the specific form of face orientator 12 or core orientator 20. Indeed, the present face orientator 12 is depicted as comprising both a marker 30 and a plurality of profiling pins 34.

However, both are not required. In particular, the pins 34 may be omitted. Further, if desired the first mark 28 need not be pre-formed on the disc 22 and indeed is not necessary for the disc to be keyed to be the face orientator 12. For example, the disc 22 may be in the form of a"standard"disc or simple washer without the mark 28 nor the key 46. In such an embodiment, the disc 22 is simply clamped between the face orientator 12 and the bottom orientator 20. In this embodiment, when using disc 22 to form a permanent record of the orientation of the core, a geologist would not only make the second mark 32 on the disc 22 but also physically make the first mark 28 on the disc at a location rotationally aligned with the pencil 30. For convenience the first and second marks are made in a way which are distinguishable, for example use of different colours or engravings of different configuration. Clearly, the pencil 30 may be formed to mark both the core 18 and the first mark 28 of disc 22.

This may be achieved by sharpening the pencil 30 at both ends, so that when the core drill is initially lowered on the toe of the hole it makes both the face mark 14 and the first mark 28.

It would also be recognised that the key 46 can serve as the first mark 28. As readily apparent from the embodiments shown in Figures 1-5, the key 46 and the first mark 28 are radially aligned. Therefore they also are both in rotational alignment with the face mark 14.

Accordingly the first mark 28 can be dispensed with and

the key 46 relied upon by itself as also functioning at the first mark 28. With reference to Figure 7, in a further variation to this and to assist in use of the disc 22, the key 46 may be moved to extend upright of (ie perpendicular to) a radial face of the disc 22 preferably adjacent an outer circumferential edge of the disc 22. In order to rotationally lock the disc 22 to the face orientator 12, the flange 42 is increased in diameter and the notch 44 repositioned to form a complementary recess on the flange 42 to the key 46. Therefore in use, the disc 22 remains clamped between the face orientator 12 and bottom orientator 20 with the key 46 locked in the recess 44 which prevents relative rotational movement between the disc 22 and the face orientator 12. One further benefit of this arrangement is that the key 46 also acts as the mark C of the first embodiment. Indeed it acts as a foolproof mark in this regard because the disc 22 will only sit flat on the card 120 when the key 46 faces up.

Thus in this embodiment the key 46 also acts as the first mark 28 and the face mark C.

In yet a further embodiment, the pencil 30 may be replaced by a double-ended indenting tool which indents the face 16 of the core 18 to form the mark 14 and marks by way of punching or indenting the first mark 28 on the disc 22.

All modifications and variations in the present invention as would be obvious to a person of ordinary skill in the art are deemed to be with the scope of the present invention, the nature of which is to be determined from the above description and the appended claims.