TECHNICAL FIELD

[0001] This invention relates to sample collection. More particularly, the invention is concerned with an apparatus for, and a method of, collecting a sample from bulk material. The sample may be required for any appropriate purpose; for example, inspection or analysis.

[0002] The invention is particularly useful for the collection of a sample of bulk material as a vertical column from within the bulk material. In particular, the invention facilitates extraction of a vertical column from within the bulk material. [0003] The invention has been devised particularly, although not necessarily solely, in relation to collection of geological samples in exploration drilling. Accordingly, the following discussion in relation to background art is provided in the context of collection of samples in exploration drilling such as mineral exploration drilling. However, the invention may have application in various other fields, including for example collection of samples of mud, cement, sludge, paste, soil, and powdered and granular materials stored in bulk.

BACKGROUND ART

[0004] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0005] In exploration drilling such as mineral exploration drilling, there is a need for sample analysis to determine the geology of the earth formation being drilled. [0006] There have been various proposals involving use of drilling cuttings as a source of analysis to determine the geology of the earth formation that is being drilled. The drilling cutting may be accumulated in bulk quantities, and representative samples may be extracted from the bulk material for analysis as required.

[0007] The drilling cuttings may be contained in a thick or dewatered slurry which is accumulated in batches, with each batch being related to the axial location within the borehole at which the respective drilling cuttings have been collected. In this regard, the batches may be retrieved incrementally in time intervals which represent specific spatial intervals of the borehole. Furthermore, each part of a vertical column within each batch may be reflective of the strata from the underground location from which the particular batch of drilling cuttings was obtained.

[0008] In obtaining representative samples from the batches of drilling cuttings, it is desirable to collect the sample uniformly as a vertical column from within the bulk material, thereby continuing to reflect the strata of the underground location to which the sample relates. Additionally, it is desirable that the collection procedure not adversely affect the reliability of the extracted sample by causing mixing of particulate material during the collection process. Mixing of particulate material during the collection process might result in the collected sample being less than truly representative of the strata within bulk material.

[0009] It is against this background that the present invention has been developed.

[0010] While the present invention was developed against this background, it need not necessarily be used for the purposes discussed. Rather, the invention may merely offer an alternative arrangement for sample collection.

SUMMARY OF INVENTION [0011] According to a first aspect of the invention there is provided a sample collection apparatus comprising a tubular spear portion for receiving a sample of material, the tubular spear portion comprising a plurality of longitudinal elements adapted to be arranged together in an assembled condition to define the tubular portion, the tubular spear portion being adapted to be selectively opened through movement of at least one longitudinal element relative to another. [0012] The tubular spear portion may have first and second opposed end sections, the first end section providing an end through which sample material can be received within the tubular portion, and a retaining means adapted to be connected to the second end section of the tubular spear portion for releasably retaining the longitudinal elements together in the assembled condition defining the tubular spear portion.

[0013] Preferably, there are two longitudinal elements defining the tubular spear portion.

[0014] The relative movement between the longitudinal elements may, in one instance, comprise axial movement of said at least one longitudinal element relative to another. The axial movement may, for example, comprise sliding movement of said at least one longitudinal element relative to another.

[0015] The relative movement between the longitudinal elements may, in another instance, comprise separation of the longitudinal elements. With this arrangement, the tubular spear portion may be adapted to be selectively opened by splitting it apart through separation of the longitudinal elements.

[0016] The retaining means may be selectively operable to lock the longitudinal elements against relative movement one with respect to another.

[0017] More particularly, the retaining means may be adapted to selectively restrain the longitudinal elements against axial displacement one with respect to another and to also exert radial compression on the assembled tubular portion, thereby retaining the longitudinal elements together in the assembled condition defining the tubular portion.

[0018] The retaining means may be selectively operable to permit the tubular spear portion to be disassembled. Disassembly of the tubular spear portion may serve to expose at least a portion of sample material collected within the assembled tubular portion. Disassembly of the tubular spear portion may also facilitate cleaning of the longitudinal elements. [0019] The retaining means may be selectively operable to permit sliding movement of one longitudinal element axially relative to another into an offset arrangement to expose at least a portion of sample material collected within the assembled tubular portion. [0020] Accordingly the retaining means may have two operative conditions, being a first condition operable to lock the longitudinal elements against relative movement with respect to each other, and a second condition operable to retain the longitudinal elements together while also permitting sliding movement of one longitudinal element axially relative to another into an offset arrangement to expose at least a portion of sample material collected within the assembled tubular portion.

[0021] The retaining means may have also have a release condition adapted to allow disassembly of the tubular spear portion; that is, to allow separation of the longitudinal elements. [0022] The retaining means may comprise a collar portion provided on each longitudinal element of the tubular portion at one end thereof, the collar portions being adapted to define a locking collar when the longitudinal elements are arranged together in the assembled condition, and a locking cap adapted to be fitted onto the locking collar and operable to secure the collar portions together. [0023] Each longitudinal element may comprise a longitudinal wall section.

[0024] The longitudinal wall section is preferably relatively thin in cross-section to minimise disturbance to bulk material into which the tubular spear portion may be plunged during use of the apparatus to extract a sample of bulk material.

[0025] The locking collar may comprise an annular inner portion and at least one lug projecting radially from the inner portion. In an embodiment there are two lugs. The two lugs may be disposed in diametrally opposed relation.

[0026] The annular inner portion may comprise a plurality of sectors, each corresponding to a respective one of the longitudinal elements defining the tubular portion. In an embodiment comprising two longitudinal elements defining the tubular portion, there are two annular sectors, Typically, the two annular sectors are each semi-annular.

[0027] Each lug may comprise two lug portions, each lug portion being provided on one of two adjacent annular sectors. In an embodiment comprising two longitudinal elements defining the tubular portion and two annular sectors, each annular section may have two lug portions each at opposed ends thereof.

[0028] The locking cap may define a cavity in which the locking collar can be received and retained. With this arrangement, the locking cap may function as a clamping ring for holding the locking collar portions together. [0029] The locking cap and the tubular spear portion may be adapted for relative rotation between a first rotational condition in which the locking collar can be selectively received into and removed from the cavity, and a second rotational condition in which the locking collar is captively retained in the cavity with the collar portions secured together. In other words, the locking collar is constrained against removal from the cavity when the locking cap is in the second rotational condition.

[0030] The locking cavity may have an outer wall configured to permit entry of the locking collar into the cavity when the locking cap is in the first rotational condition. [0031] The outer wall may be defined by flanges in circumferentially spaced relation to define gaps in the outer wall through which the lugs of the locking collar can pass. In an embodiment comprising two longitudinal elements, there may be two flanges in opposed relation, with the two flanges being circumferentially spaced to define two gaps in the outer wall through which the lugs of the locking collar can pass.

[0032] The retaining means may further comprise compression means for exerting radial compression on the assembled tubular portion.

[0033] The compression means may comprise a compression fitting adapted to be located between the locking cap and a further locking member. [0034] The locking cap and the further locking member may be adapted to be threadedly interconnected with the compression fitting clamped therebetween. The locking cap and the further locking member may be selectively operable to cause the compression means to effect clamping engagement on the assembled spear tubular portion.

[0035] The compression fitting may comprise a clamping portion adapted to surround the assembled tubular portion in clamping engagement therewith to exert radial compression on the assembled tubular portion.

[0036] The compression fitting may comprise two clamping portions in opposed relation, one adapted for cooperation with the locking cap and the other adapted for cooperation with the further locking member.

[0037] Each clamping portion may comprise a plurality of circumferentially spaced clamping fingers adapted to be urged into clamping engagement with the assembled tubular portion. [0038] The compression fitting may further comprise a central ring section to which the clamping fingers are integrally attached and from which the clamping fingers extend in opposed relation.

[0039] Each clamping portion may be of frusto-conical shape, and the locking cap and the further locking member may each have a frusto-conical mouth for receiving the respective frusto-conical clamping portion.

[0040] The retaining means may further comprise a flexible seal between the locking cap and the locking collar of the assembled tubular portion.

[0041] The retaining means may further comprise a flexible seal between the locking cap and a portion of the assembled tubular portion spaced from the locking collar.

[0042] With this arrangement, in use of the sample collection apparatus, the tubular spear portion can be plunged into bulk material from which a sample is to be extracted, with the end of the tubular spear portion opposite the retaining means leading at entry, whereby sample material can enter the tubular spear portion through the leading end thereof. The tubular spear portion can then be withdrawn, extracting the sample material received therein. The tubular spear portion is then opened through movement of at least one longitudinal element relative to another to provide access to the extracted sample material. Because the retaining means on the tubular spear portion is remote from the leading end of the tubular spear portion plunged into the bulk material, it does not provide an impediment to entry of the tubular portion into the bulk material and also does not cause a disturbance to the bulk material. [0043] The sample collection apparatus thus provides a spearing device for sample collection.

[0044] According to a second aspect of the invention there is provided a sample collection apparatus comprising a tubular portion having opposed end sections, the tubular portion comprising a plurality of longitudinal elements adapted to be arranged together in an assembled condition to define the tubular portion, and a retaining means adapted to be operably connected to one end section of the tubular portion for releasably retaining the longitudinal elements together in the assembled condition defining the tubular portion.

[0045] According to a third aspect of the invention there is provided a sample collection apparatus comprising a tubular spear portion for receiving a sample of material, the tubular portion having opposed end sections, the tubular spear portion comprising two longitudinal elements adapted to be arranged together in an assembled condition to define the tubular spear portion, and a retaining means adapted to be operably connected to one end section of the tubular spear portion for releasably retaining the two longitudinal elements together in the assembled condition defining the tubular spear portion, the retaining means being adapted to restrain the two longitudinal elements against axial displacement one with respect to another and to exert radial compression on the assembled tubular spear portion, thereby retaining the two longitudinal elements together in the assembled condition defining the tubular spear portion.

[0046] According to a fourth aspect of the invention there is provided a sample collection apparatus comprising a tubular spear portion for receiving a sample of material, the tubular portion having opposed end sections, the tubular spear portion comprising two longitudinal elements adapted to be arranged together in an assembled condition to define the tubular spear portion, and a retaining means adapted to be operably connected to one end section of the tubular spear portion for releasably retaining the two longitudinal elements together in the assembled condition defining the tubular spear portion, the retaining means having two operative conditions, being a first condition operable to lock the two longitudinal elements against relative movement with respect to each other, and a second condition operable to retain the two longitudinal elements together while permitting sliding movement of one longitudinal element longitudinally relative to the other into an offset arrangement to expose at least a portion of sample material collected within the assembled tubular portion.

[0047] The sample collection apparatus according to the second, third or fourth aspect of the invention may optionally have any one or more of the features recited above in relation to the sample collection apparatus according to the first aspect of the invention, as appropriate.

[0048] According to a fifth aspect of the invention there is provided a method of sample collection using a sample collection apparatus according to any one of the preceding aspects of the invention. [0049] According to a sixth aspect of the invention there is provided a method of sample collection from bulk material, comprising: inserting a tubular spear portion into the bulk material to receive sample material from within the bulk material; withdrawing the tubular spear portion to extract the received sample material; opening the tubular spear portion to provide access to the received sample material; and removing the received sample material from the opened tubular spear portion, wherein the tubular spear portion is provided as a plurality of longitudinal elements and wherein the tubular spear portion is opened by moving one longitudinal element longitudinally relative to another longitudinal element to expose at least a portion of sample material collected within the assembled tubular portion.

[0050] In one instance, said one longitudinal element may be moved by separating it from said another longitudinal element. [0051] In another instance, said one longitudinal element may be moved by moving it axially with respect to said another longitudinal element. More particularly, said one longitudinal element may be moved by sliding it axially with respect to said another longitudinal element into an offset arrangement to expose at least a portion of sample material collected within the assembled tubular portion.

[0052] The method may further comprise use of apparatus according to the first, second, third or fourth aspect of the invention to provide the tubular spear portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Further features of the present invention are more fully described in the following description of a non-limiting embodiment thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 is a side view of the embodiment of the sample collection apparatus according to the invention;

Figure 2 is a sectional view on line 2-2 of Figure 1 ; Figure 3 is a schematic exploded perspective view of the embodiment of the sample collection apparatus;

Figure 4 is a schematic perspective view of a locking cap forming part of the embodiment of the sample collection apparatus;

Figure 5 is a side view of the locking cap; Figure 6 is a sectional view on line 6-6 of Figure 5;

Figure 7 is a plan view of the embodiment of the sample collection apparatus; Figure 8 is a view similar to Figure 7 except that is depicted in a different rotational condition;

Figure 9 is a schematic sectional view of the sample collection apparatus in one mode of operation, in which the tubular spear portion is opened by axial movement of two longitudinal elements thereof;

Figure 10 is a schematic sectional view of the sample collection apparatus in another mode of operation, in which the tubular spear portion is opened by separation of two longitudinal elements thereof;

Figure 1 1 is a schematic sectional view of the sample collection apparatus in operation extracting a sample of material from a batch of bulk material in a container; and

Figure12 is a schematic side view of the sample collection apparatus in operation, with the tubular spear portion opened for retrieval of the extracted sample of material.

[0054] In the drawings like structures are referred to by like numerals throughout the several views. The drawings shown are not necessarily to scale, with emphasis instead generally being placed upon illustrating the principles of the present invention.

[0055] The figures which constitute the drawings depict an exemplary embodiment of the invention. The embodiment illustrates certain configurations; however, it is to be appreciated that the invention can take the form of many configurations, as would be obvious to a person skilled in the art, whilst still embodying the present invention. These configurations are to be considered within the scope of this invention. DESCRIPTION OF EMBODIMENT

[0056] Referring to the drawings, there is shown an example embodiment of a sample collection apparatus which provides a spearing device 10 for collection of a sample of bulk material. The bulk material may take any appropriate form, and in this embodiment comprises a (thick) dewatered slurry containing drilling cuttings accumulated in batches. The slurry containing drilling cuttings may comprise the output of a solids control system forming part of a drilling fluid system (commonly known as a mud system) used in conjunction with a drilling process. The drilling process may, for example, comprise exploration drilling, such as mineral exploration drilling by way of diamond drilling. A solids control system likely to be particularly suitable is of the type disclosed in Australian Patent Applications 2012318265 and 2013204746, the contents of which are incorporated herein by way of reference. The slurry containing drilling cuttings may, for example, be collected by way of a collection system as described and illustrated in Australian Patent Application 2016213905, the contents of which are incorporated herein by way of reference.

[0057] The spearing device 10 has a tubular spear portion 1 1 which is adapted to be plunged into a batch of the bulk material from which the sample is to be extracted. Typically, the tubular spear portion 1 1 would be plunged vertically into a batch of the bulk material to receive the sample material as a column within the tubular spear portion. Because the sample material is received as a column within the the tubular spear portion 1 1 , it typically reflects the strata profile of the location within the batch of the bulk material from which it has been extracted.

[0058] The tubular spear portion 1 1 has opposed end sections 12, 13, which will hereinafter be referred to as distal end section 12 and proximal end section 13. Distal end section 12 defines a leading end 14 which is open and which is adapted to lead upon entry of the tubular spear portion 1 1 into the bulk material. The tubular spear portion 1 1 also has a central passage 15 which opens onto the leading end 14. Upon plunging of the tubular spear portion 1 1 into the bulk material, sample material can enter the central passage 15 of the tubular spear portion 1 1 through the open leading end 14. The tubular spear portion 11 can then be withdrawn, extracting the sample material received within the tubular spear portion 1 1 .

[0059] The tubular spear portion 1 1 comprises a plurality of longitudinal elements 17 which can be assembled to provide the tubular spear portion 1 1 and which can be moved one relative to another to provide access to the extracted sample material. In this embodiment there are two longitudinal elements 17 defining the tubular spear portion 11 .

[0060] A retaining means 19 is provided for releasably retaining the longitudinal elements 17 together in an assembled condition to provide the tubular spear portion 1 1. The retaining means19 is disposed remotely from the leading end 14 of the tubular spear portion 1 1 so as not to provide an impediment to entry of the tubular spear portion into the bulk material and also not to cause adverse disturbance to the bulk material as the tubular spear portion is plunged into the bulk material. More particularly, the retaining means 19 is provided at proximal end section 13. The retaining means 19 is adapted to releasably restrain the longitudinal elements 17 against axial displacement one with respect to another, and to exert radial compression on the assembled tubular spear portion 1 1 at the proximal end section 13, thereby retaining the longitudinal elements 17 together in the assembled condition defining the tubular spear portion 11 . The retaining means 19 is adapted to be selectively actuated to allow the tubular spear portion 1 1 to be opened to provide access to the extracted column of sample material, thereby allowing the extracted sample material to be removed from the tubular spear portion. The arrangement may allow the extracted sample material to be removed from the tubular spear portion 1 1 in a condition in which it reflects the strata profile of the location within the bulk material from which it has been extracted. In this way, the integrity of the extracted sample can be maintained so that it is a truly representative sample.

[0061] The tubular spear portion 1 1 can be opened through movement of at least one longitudinal element 17 relative to another. [0062] The relative movement may, in one instance, comprise axial movement of said at least one longitudinal element 17 relative to another, as shown in Figures 9 and 12. In the arrangement shown featuring two longitudinal elements 17, the axial movement comprises sliding movement of longitudinal element 17a relative to the other longitudinal element 17b. [0063] The relative movement may, in another instance, comprise separation of said at least one longitudinal element 17 relative to another longitudinal element 17, as shown in Figure 10. In the arrangement shown featuring two longitudinal elements 17a, 17b, the two longitudinal elements are separated by moving them apart apart. In other words, the tubular spear portion 1 1 is selectively opened by splitting it apart to separate the longitudinal elements 17,

[0064] In this embodiment there are two longitudinal elements 17a, 17b defining the tubular spear portion 1 1 , as mentioned above. In the arrangement shown, the tubular spear portion 1 1 is annular is cross-section, and accordingly the central passage 15 is circular in cross-section. With this arrangement, each longitudinal element 17 is semi-annular is cross-section.

[0065] Each longitudinal element 17 comprises a longitudinal wall section 21 of semi-annular cross-section having two opposed longitudinal edges 23. The two longitudinal elements 17 are adapted to be positioned is side-by-side relation in the assembled condition defining the tubular spear portion 1 1 , with the longitudinal edges 23 contacting in abutting relation. In this embodiment, each longitudinal edge 23 presents a planer surface for abutting contact with the planer surface on the counterpart longitudinal edge 23 with which it is in contact. However, other arrangements are possible. In another arrangement, for example, the longitudinal edges 23 of the longitudinal elements 17 may be adapted to interconnect. The interconnection may be by way of an interlocking connection; for example, one longitudinal edge 23 may be of a male configuration and the counterpart longitudinal edge may be of a mating female configuration.

[0066] The longitudinal wall section 21 is relatively thin in cross-sectional profile to minimise disturbance to bulk material into which the tubular spear portion 1 1 is plunged during use of the spearing device 10 to extract a sample of bulk material. [0067] The retaining means 19 may comprise a locking collar 31 on the tubular spear portion 1 1 at the proximal end section 13, and a locking assembly 33 adapted for engagement with the locking collar 31 and the proximal end section 13 of the tubular spear portion 1 1 .

[0068] The locking assembly 33 comprises a locking cap 35, a further locking member 37 and a compression fitting 39. The arrangement is such that the locking cap 35 and the further locking member 37 are adapted to be threadedly interconnected, with the locking cap 35 in engagement with the locking collar 31 and the compression fitting 39 clamped between the locking cap 35 and the further locking member 37 to exert radial compression on the assembled tubular portion, as will be described in more detail later. For this purpose, the locking cap 35 has a male thread portion 36 and the further locking member 37 has a female thread portion 38.

[0069] The locking collar 31 comprises an annular inner portion 41 and two lugs 43 disposed in diametrally opposed relation.

[0070] The locking collar 31 comprises two collar portions 45 each provided on a respective one of the two longitudinal elements 17, the arrangement being that the two collar portions 45 cooperate to define the locking collar 31 when the two longitudinal elements 17 are arranged together in the assembled condition to define the tubular spear portion 1 1 . In the arrangement shown, collar portion 45a is provided on longitudinal element 17a and collar portion 45b is provided on longitudinal element 17b.

[0071] Each collar portion 45 comprises a respective one of two annular sectors 51 , 52 which cooperate to define the annular inner portion 41 when the two longitudinal elements 17 are arranged together in the assembled condition to define the tubular spear portion 1 1 . [0072] The two lugs 43 comprise one lug 53 and another lug 54.

[0073] Each collar portion 45 further comprises two lug portions, one lug portion comprising part of lug 53 and the other lug portion comprising part of lug 54. In other words, collar portion 45a comprises annular sector 51 and lug portions 53a, 54a, with the lug portions 53a, 54a being at opposed ends of the annular sector 51 , as best seen in Figure 3. Similarly, collar portion 45b comprises annular sector 52 and lug portions 53b, 54b, with the lug portions 53b, 54b being at opposed ends of the annular sector 52, also as best seen in Figure 3.

[0074] When the two longitudinal elements 17 are arranged together in the assembled condition to define the tubular spear portion 1 1 , lug portions 53a, 53b cooperate to constitute lug 53, and lug portions 54a, 54b cooperate to constitute lug 54.

[0075] The locking cap 35 comprises a body 61 having a central passage 63 within which the two longitudinal elements 17 can be slidingly received when arranged together in the assembled condition to define the tubular spear portion 1 1 . The locking cap 35 functions as a band for holding the two longitudinal elements 17 together in side-by-side relation to define the tubular spear portion 1 1 , with the respective longitudinal edges 23 contacting in abutting relation. The locking cap 35 is also operable to function as a clamping ring for holding the locking collar portions 45a, 45b together, as will become more apparent later.

[0076] The central passage 63 has a top end section 65 and a bottom end section 67.

[0077] The body 61 defines a locking cavity 71 about the top end section 65, in which the locking collar 31 can be received and retained. The locking cavity 71 is bounded by an inner wall 73, and outer wall 75 and a side wall 77 extending between the inner and outer walls 73, 75.

[0078] The body 61 of the locking cap 35 and the two longitudinal elements 17 received in the central passage 63 are adapted for relative rotation. In other words, relative rotation between the locking cap 35 and the tubular spear portion 1 1 . More particularly, the body 61 of the locking cap 35 and the two longitudinal elements 17 are rotatable relative to each other between a first rotational condition (as shown in Figure 8) in which the locking collar portions 45a, 45b can be selectively received into and removed from the locking cavity 71 , and a second rotational condition (as shown in Figure 7) in which the locking collar portions 45a, 45b are captively retained in the locking cavity 71 with the locking collar portions 45a, 45b secured together. The relative rotation may involve rotation of the two longitudinal elements 17 relative to the locking cap 35, or rotation of the locking cap 35 relative to the two longitudinal elements 17, with the former more likely. The relative rotation may alternatively involve rotation of both the two longitudinal elements 17 and the locking cap 35. With this arrangement, the locking collar 31 is constrained against removal from the cavity 71 when the assembly is in the second rotational condition. Further, the two longitudinal elements 17 are constrained against axial displacement one relative to the other when the assembly is in the second rotational condition.

[0079] For this purpose, the outer wall 75 of the locking cavity 71 is configured to permit entry of the locking collar portions 45 into the cavity when the body 61 of the locking cap 35 and the two longitudinal elements 17 are in the first rotational condition. In the arrangement shown, the outer wall 75 is defined by two flanges 81 in circumferentially spaced relation to define gaps 83 in the outer wall through which the lugs 43 of the locking collar 31 can pass. The two flanges 81 are in opposed relation. [0080] When the locking collar 31 is received within the locking cavity 71 , the lugs 43 locate against inner wall 73 and are confined by the surrounding side wall 77. The locking collar 31 can be received into, and removed from, this position within the locking cavity 71 when the assembly comprising the body 61 of the locking cap 35 and the two longitudinal elements 17 is in the first rotational condition, as shown in Figure 8. In this condition, the gaps 83 in the outer wall 75 are in alignment with the lugs 43, thereby permitting the lugs to pass through the gaps for reception into, or removal from, the locking cavity 71 . Upon relative rotation between the body 61 of the locking cap 35 and the two longitudinal elements 17 into the second rotational condition relative to the tubular spear portion 1 1 (as shown in Figure 7), the gaps 83 are moved out of registration with the lugs 43, such that the two flanges 81 overlay the lugs 43 to impede removal of the locking collar 31 from the cavity 71 . In this way, the locking collar 31 is constrained against removal from the cavity 71 .

[0081] In this embodiment, the assembly comprising the body 61 of the locking cap 35 and the two longitudinal elements 17 is relatively rotatable through 90 degrees in moving between the first and second rotational conditions.

[0082] The retaining means 19 further comprise compression means 81 for exerting radial compression on the assembled tubular spear portion 1 1 . The compression means 81 comprises the compression fitting 39. [0083] The compression fitting 39 comprises two clamping portions 83, 85 in opposed relation, with clamping portion 83 adapted for cooperation with the locking cap 35 and clamping portion 85 adapted for cooperation with the further locking member 37.

[0084] Each clamping portion 83, 85 comprise a plurality of circumferentially spaced clamping fingers 87 adapted to be urged into clamping engagement with the assembled tubular portion 1 1 .

[0085] The compression fitting 39 further comprise a central ring section 88 to which the clamping fingers 87 are integrally attached and from which the clamping fingers extend in opposed relation.

[0086] Each clamping portion 83, 85 is configured to be of frusto-conical shape. The locking cap 35 has a frusto-conical mouth 89 at the bottom end section 67 of the central passage 63 for receiving the frusto-conical clamping portion 83. Similarly, the further locking member 37 has a frusto-conical mouth 90 for receiving the frusto-conical clamping portion 85. With this arrangement, when the locking cap 35 and the further locking member 37 are threadedly interconnected, the compression fitting 39 is clamped between the locking cap 35 and the further locking member 37. Interaction between the frusto-conical clamping portions 83, 85 and the respective frusto-conical mouths 89, 90 in which they are received, has the effect of urging the clamping fingers 87 radially inwardly to grip and exert radial compression on the assembled tubular spear portion 1 1 .

[0087] In the arrangement shown, the locking cap 35 and the further locking member 37 are configured to facilitate manipulation manually; that is, the locking cap 35 and the further locking member 37 are configured to be rotated manually when being threaded together and also unthreaded. This may be through provision of a gripping formation such as knurling 91 on exposed surfaces of the locking cap 35 and the further locking member 37 to facilitate gripping for this manual operation.

[0088] In this embodiment, the locking cap 35 and the further locking member 37 may be made of metal, such as phosphor bronze, and the compression fitting 39 may be of a plastics material, such as acetal. It will, however, be understood that any other appropriate materials may also be used for the various parts. [0089] The retaining means 19 may optionally further comprises a first flexible seal (not shown) between the locking cap 35 and the locking collar 31 of the assembled tubular spear portion 11 . This first flexible seal may comprise an O- ring seal received within a groove (not shown) provided in the inner wall 73 of the locking cavity 71 .

[0090] The retaining means 19 may optionally further comprise second flexible seal (not shown) between the locking cap 35 and a portion of the assembled tubular spear portion 1 1 spaced from the locking collar 31 . This second flexible seal may comprise an O-ring seal received within a groove (not shown) provided in the locking cap 35 about the perimeter of the central passage 63 adjacent has a top end section 65 thereof.

[0091] In assembling the spearing device 10, the two longitudinal elements 17 are positioned is side-by-side relation to define the tubular spear portion 1 1 , with the longitudinal edges 23 contacting in abutting relation. The two longitudinal elements 17 are inserted into the central passage 63 of the locking cap 35, entering through the top end section 65. With the body 61 of the locking cap 35 and the two longitudinal elements 17 in the first rotational condition, the parts are then moved together such that the locking collar 31 is received in the locking cavity 77, with the lugs 43 passing through the gaps 83 in the outer wall 75 of the locking cap. The body 61 of the locking cap 35 and the two longitudinal elements 17 are then moved into the second rotational condition, thereby securing the locking collar 31 in the locking cavity 77. The compression fitting 39 and the further locking member 37 are then positioned on the two longitudinal elements 17. The further locking member 37 is screwed into engagement with the locking cap 35, with compression fitting 39 clamped therebetween, causing the compression fitting to exert radial compression on the assembled tubular spear portion 1 1 . This represents a first operating condition of the retaining means 19 in which the longitudinal elements 17a, 17b are locked against relative movement with respect to each other. The spearing device 10 is then in readiness for use. [0092] In use, an operator grasps the sample collection apparatus 10 adjacent proximal end section 13 of the tubular spear portion 1 1 , typically around the retaining means 19, and plunges the distal end section 12 into bulk material from which a representative sample is to be extracted, whereby sample material can enter the tubular spear portion through the leading end 14. This is depicted schematically in Figure 1 1 , where the bulk material comprises a batch of dewatered slurry 101 containing drilling cuttings some of which are required to be extracted to provide a sample for analysis. In the arrangement shown, the batch of dewatered slurry 101 is contained within a container 103 such as a sample bag 105 held in a pot 107, with the top portion 105a of the bag folded outwardly over the top edge of the pot. A column 101 a of the dewatered slurry 101 is received within the central passage 15 within the tubular spear portion 1 1 . Because the retaining means 19 on the tubular portion 1 1 is remote from the leading end 14 of the tubular spear portion 11 plunged into the bulk material, it does not provide an impediment to entry of the tubular spear portion into the bulk material and also does not cause adverse disturbance to the bulk material.

[0093] The tubular spear portion 1 1 can then be withdrawn, extracting the column 101 a of the dewatered slurry 101 received within the tubular portion as sample material. The extracted sample material received within the tubular spear portion 1 1 remains within the confines of the tubular spear portion 1 1 , at least initially, owing to its thick consistency.

[0094] After extraction of a sample from bulk material, the sample can be retrieved from within the tubular spear portion 1 1 . This may be done by opening the the tubular spear portion 1 1 to expose the sample material for retrieval. More particularly, the retaining means 19 is actuated to allow relative movement between the longitudinal elements 17 to provide access to the extracted sample material. The retrieval process may involve pouring the sample material from the opened spear portion 1 1 . The sample material may (additionally or alternatively) be retrieved from the opened spear portion 1 1 in any other appropriate way, including shaking and/or scraping.

[0095] There are several ways in which the spearing device 10 can be opened to expose the sample material for retrieval, as previously described. [0096] One way of opening the spearing device 10 to expose the sample material for retrieval may involve moving the retaining means 19 from the first operative condition in which the longitudinal elements 17a, 17b are locked against relative movement with respect to each other to a second operative condition in which in which the longitudinal elements 17a, 17b are retained together while permitting sliding movement of one longitudinal element axially relative to another into an offset arrangement to expose at least a portion of sample material collected within the assembled tubular portion.

[0097] The retaining means 19 can be actuated to move from the first operative condition to the second operative condition by loosening of the threaded interconnection between the locking cap 35 and the further locking member 37, so reducing the clamping action of the compression fitting 39 to permit relative rotation between the locking cap 31 and the tubular portion 11 , and then rotating the assembly from the second rotational condition to the first rotational condition, as previously described. It is notable that this does not involve disassembly of the retaining means 19, but rather merely loosening of the threaded interconnection between the locking cap 35 and the further locking member 37 so reducing the clamping action of the compression fitting 39 to an extent sufficient to permit relative rotation between the locking cap 31 and the tubular portion 1 1 , and also axial sliding movement between the two tubular spear portions 17a, 17b.

[0098] The tubular spear portion 1 1 can be opened through axial movement of one longitudinal element 17 relative to another, as shown in Figure 9 and 12. In the arrangement shown, the axial movement comprises sliding movement of longitudinal element 17a relative to longitudinal element 17b into an an offset arrangement to expose at least a portion of sample material collected within the assembled tubular portion. With the spearing device 10 held in an inclined disposition as shown in Figure 12, , the lower end portion of longitudinal element 17b may function as a trough or chute 1 11 along and from which sample material can be discharged, such as by pouring.

[0099] Another way of opening the spearing device 10 to expose the sample material for retrieval may involve disassembly of the spearing device 10 in a procedure which is more or less the reverse of the assembly procedure described above. This would allow the two longitudinal elements 17a, 17b to be separated by moving them apart, as depicted in Figure 10. In other words, the tubular spear portion 1 1 is selectively opened by splitting it apart to separate the longitudinal elements 17.

[00100] From the foregoing, it is evident that the present embodiment provides a simple yet highly effective arrangement: (i) by which a representative sample can be extracted from bulk material without undue disturbance of the bulk material; and (ii) by which the extracted sample may be retrieved in a condition in which it reflects the strata profile of the location within the bulk material from which it has been extracted.

[00101] It should be appreciated that the scope of the invention is not limited to the scope of the embodiment described as an example.

[00102] In this embodiment the tubular spear portion has been described as being plunged vertically into bulk material to retrieve a representative sample as a vertical column from within the bulk material. This need not necessarily always be the case. There may be applications, for instance, where a sample is not required to represent a vertical column from within the bulk material, in which case the tubular spear portion may be inserted into the bulk material in an orientation other than vertical.

[00103] While the present invention has been described in terms of a preferred embodiment in order to facilitate better understanding of the invention, it should be appreciated that various modifications can be made without departing from the principles of the invention. Therefore, the invention should be understood to include all such modifications within its scope.

[00104] This disclosure is intended to explain how to fashion and use various embodiments in accordance with the technology rather than to limit the true, intended, and fair scope and spirit thereof. The foregoing description is not intended to be exhaustive or to be limited to the precise forms disclosed. Modifications or variations are possible in light of the above teachings. The embodiment was chosen and described to provide the best illustration of the principle of the described technology and its practical application, and to enable one of ordinary skill in the art to utilise the technology in various embodiments and with various modifications as are suited to the particular use contemplated. [00105] Reference to positional descriptions, such as "upper", "lower", "top", and "bottom", "front", "rear" and "side" are to be taken in context of the embodiments depicted in the drawings, and are not to be taken as limiting the invention to the literal interpretation of the term but rather as would be understood by the skilled addressee.

[00106] Additionally, where the terms "system", "device" and "apparatus" are used in the context of the invention, they are to be understood as including reference to any group of functionally related or interacting, interrelated, interdependent or associated components or elements that may be located in proximity to, separate from, integrated with, or discrete from, each other.

[00107] Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.