A cable anchor securing device

Abstract

A cable anchor securing device is provided. The device includes a tubular body having a front end and a rear end which define an open-ended passage. The body operatively receives a plurality of elongate wedge segments inserted into the passage at its rear end around a cable running through the passage. The wedge segments are movable within the passage between an expanded condition in which the wedge segments are generally circumferentially spaced and the cable can be inserted between leading ends of the wedge segments, and a collapsed condition in which movement of the wedge segments towards the front end of the body within the passage causes the wedge segments to secure about the cable. A wedge spacer is then provided which is shaped to hold the wedge segments in an expanded condition and includes a surface which is engageable by a free end of the cable inserted between the wedge segments from the front end of the passage.

Description

[0001] A CABLE ANCHOR SECURING DEVICE

[0002] FIELD

[0003] This disclosure relates to cable anchors for high tensile cables used in mining and related applications.

[0004] BACKGROUND

[0005] Cable anchor systems are widely used in the mining environment for the tensioning of cables in the rock roof or hanging wall to ensure a safe working environment for the miners. The mechanical components of the cable anchor system are fitted to a cable to make up the mechanical cable anchor and to secure the cable into the rock by allowing pre-tensioning of the cable and then maintaining tension on the cable by locking it in place.

[0006] Typical cable anchor systems include wedge and barrel systems wherein the wedge assembly secures around a cable inserted therethrough as the wedge assembly moves deeper into the tapered barrel. Movement of the cable from the rear end towards the front end, or tension which causes force in the direction of the front end, is prevented by the wedge assembly after the correct tension is applied and the wedge assembly moved in the direction of the front end and into closer proximity with the cable. At their fullest insertion into the barrel, the wedge segments of the wedge assembly form a strong friction fit over the cable and prevent its further movement. These systems are reliable and fairly straightforward to manufacture. They are thus widely used in the industry.

[0007] Handling of wedge and barrel systems often poses some problems though. The wedge segments are generally provided as an assembly which has to be inserted manually into the rear of the barrel at the time of use. This often leads to losses, typically of the wedge segments, with resultant inefficiencies as it is only at the time of use that the problem of lost wedge segments is identified.

[0008] The wedge segments are typically elongate and part-circular in cross-section. They are configured or designed such that a number of them, usually three or four, can be arranged together with their sides adjacent each other to form a tube. With the sides abutting, the diameter of the tube formed is slightly less than that of the cable which they are designed to secure in the barrel. Moving them apart thus allows the cable to be passed between them. A clip or spring typically secures the wedge segments of an assembly together at their rear end. However, the clip does not prevent inward movement of the wedge segments, especially at the opposite or free end. It is thus typical for the wedge segments to collapse inwardly towards each other, especially when inserted into a barrel. This leads to a further problem as it becomes difficult or impossible to insert a cable through the wedge segments in the barrel. The cable thus has to be inserted through the barrel and the wedge segments then fed over the free end of the cable as it emerges from the barrel, and the wedge assembly only then inserted into the rear end of the barrel. This unnecessarily complicates assembly of the anchor system in use.

[0009] The preceding discussion of the background is intended only to facilitate an understanding of the present disclosure. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge in the art as at the priority date of the application.

[0010] SUMMARY

[0011] In accordance with an aspect of the disclosure there is provided a cable anchor securing device which may include a tubular body defining a passage therethrough from a front end to a rear end with the passage tapering from the rear end to the front end, and a plurality of elongate wedge segments inserted in the rear end of the passage, the wedge segments each having a leading end and a trailing end with a radially extending impact surface provided at each trailing end, and the wedge segments movable in the passage to be operable between an expanded condition in which the wedge segments are generally circumferentially spaced and a cable operatively extending through the passage can be inserted between the leading ends of the wedge segments, and a collapsed condition in which movement of the wedge segments towards the front end of the tubular body within the tapered passage causes the wedge segments to move radially inwardly and secure about the cable extending therebetween, characterised in that a wedge spacer is provided which is shaped to hold the wedge segments in the expanded condition (with the wedge segments in the “start” position) and further providing a surface which is engageable by a free end of the cable inserted between the wedge segments from the front end of the passage and to permit removal of the spacer from the rear end of the wedge segments. The wedge spacer may include a plurality of arms extending in an axial direction from the surface and each arm shaped to extend between respective adjacent wedge segments. The impact surface of the wedge segments may be part-circular in cross-section.

[0012] A retainer may be provided over the rear end of the tubular body and may be capable of unidirectional movement towards the front end of the tubular body, the retainer including a skirt providing a sliding fit over the rear end of the tubular body and which extends from an annular flange, the annular flange dimensioned to engage the impact surface of the wedge segments around their outer periphery, the annulus dimensioned to permit withdrawal of the wedge spacer therethrough. A frangible or tamper evident element may be carried within the annulus of the flange to prevent withdrawal of the wedge spacer through the annulus without breaking or removal of the frangible element.

[0013] The skirt may include tooth or ratchet formations which cooperate in use with complementary formations on the tubular body to permit unidirectional movement of the retainer onto the tubular body. The ratchet formations may further include inclined annular ribs which cooperate with circumferential grooves in the tubular body.

[0014] Further features may provide a wedge spacer for use with a set of elongate wedge segments held together at a rear or trailing end and movable between an expanded condition in which a cable can be inserted through the leading or front or free ends of the wedge segments and a collapsed condition in which the leading or front or free ends of at least some of the wedge segments abut or in which the leading or front or free ends of the wedge segments collapse towards each other to prevent a cable from being inserted therebetween, the wedge spacer including a body shaped to operatively hold the wedge segments in the expanded condition and further providing a surface which engages the cable inserted between the wedge segments from the leading or front or free ends thereof and which permits withdrawal of the spacer from the rear or trailing end of the wedge segments. The wedge spacer body may include a plurality of arms extending in an axial direction from the surface and each arm shaped to extend between respective adjacent wedge segments. The surface may be provided by a ring having an inner diameter less than that of the periphery of the rear end of the wedge segments. The arms may extend between the wedge segments.

[0015] Even further features may provide a retainer for a wedge spacer which includes a closure or cap shaped to fit over a rear end of a wedge assembly operatively received within a passage defined by a tubular body, the retainer capable of unidirectional movement towards the tubular body to urge the wedge assembly deeper into the passage, the closure including a skirt which engages over the tubular body and an inwardly extending flange at its end, the flange dimensioned to engage the rear or trailing end of the wedge segments around their periphery with a frangible or tamper evident element carried internally of the flange to prevent withdrawal of the wedge spacer from the flange without breaking or removal of the frangible element. The periphery of the rear end of the wedge segments may have greater diameter than the wedge spacer surface. The skirt may include tooth or ratchet formations which cooperate in use with complementary formations on the tubular body to permit unidirectional movement of the retainer onto the tubular body. The tooth or ratchet formations may include inclined annular ribs which cooperate with circumferential grooves in the tubular body.

[0016] Embodiments of the technology will now be described, by way of example only, with reference to the accompanying drawings.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the drawings:

[0019] Figure 1 is an exploded view of an exemplary embodiment of a cable anchor securing device;

[0020] Figure 2 is a rear perspective partial section view of the cable anchor securing device in Figure 1 in the expanded condition;

[0021] Figure 3 is a rear perspective section view of the cable anchor securing device in Figure 1 in the expanded condition;

[0022] Figure 4 is a rear perspective section view of the cable anchor securing device in Figure 1 in the expanded condition with a cable inserted at a front end;

[0023] Figure 5 is a rear perspective section view of the cable anchor securing device in Figure 1 in the expanded condition with the cable passing through wedge segments provided at a rear end;

[0024] Figure 6 is a rear perspective view of the cable anchor securing device in Figure 1 in the expanded condition with the cable passing through wedge segments provided at a rear end;

[0025] Figure 7 is a rear perspective section view of the cable anchor securing device in Figure 1 in a partially expanded condition with the cable passing through wedge segments and urging withdrawal of a frangible element;

[0026] Figure 8 is a rear perspective section view of the cable anchor securing device in Figure 1 in the partially collapsed condition with the cable through wedge segments and the frangible element and wedge spacer withdrawn; Figure 9 is a rear perspective partial section view of the cable anchor securing device in Figure 1 in a collapsed condition with the retainer urged towards a front end; and

[0027] Figure 10 is a rear perspective partial section view of the cable anchor securing device in Figure 1 in the collapsed condition with the retainer fully urged towards a front end.

[0028] DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

[0029] A cable anchor securing device is provided which includes a tubular body having a front end and a rear end. An open-ended passage extending from the rear end to the front end is defined by the body. The passage is tapered from a rear end towards a front end thereof which corresponds to the rear end and front end of the tubular body. The body operatively receives a plurality of elongate wedge segments inserted into the passage at its rear end around a cable running through the passage.

[0030] Each elongate wedge segment may be part-circular in cross-section and includes a leading end which operatively locates near the front end of the tubular body and trailing end which operatively locates at or near the rear end of the body. A radially extending impact surface is provided at each trailing end. The impact surface may have a substantially circular cross-section. A wedge retainer may be located at adjacent trailing ends of the wedge segments to secure the wedge segments together in a generally tubular configuration. The wedge retainer may be located within a groove in the outer surfaces of the wedge segments at their trailing ends. The outer diameter of the wedge segments or wedge assembly is configured to provide an inward taper corresponding to the inward taper of the passage. The outer diameter of the wedge assembly thus decreases from the trailing ends towards the leading ends. The outer surface of the wedge segments and the passage thus have corresponding, generally frusto-conical shapes. The inner diameter of the wedge assembly is consistent throughout.

[0031] The wedge segments are movable within the passage between an expanded condition in which the wedge segments are generally circumferentially spaced and a cable operatively extending through the passage can be inserted between the leading ends of the wedge segments, and a collapsed condition in which movement of the wedge segments towards the front end of the body within the passage causes the wedge segments to move radially inwardly and secure about the cable extending between the wedge segments. In the collapsed condition the wedge segments are biased by the sides of the passage into engagement with the cable, and spacing between the adjacent wedge segments is substantially reduced from the expanded condition.

[0032] Importantly, a wedge spacer is provided which is shaped to hold the wedge segments in the expanded condition and further provides a surface which is engageable by a free end of the cable inserted between the wedge segments from the front end of the passage. The surface may be provided by a ring having an inner diameter of less than that of the periphery of the trailing end or impact surface of the wedge segments and permits removal of the spacer from the trailing end of the wedge segments. The wedge spacer may be provided by a planar body, for example a disc or ring, or tubular body having an outer surface or edges on which the wedge segments rest in the expanded condition. The wedge spacer may include a plurality of arms or a plurality of spigots extending in an axial direction from the surface. The arms may be shaped to extend between the wedge segments to keep them circumferentially spaced and thus in the expanded condition.

[0033] A retainer may be provided over the rear end of the tubular body to prevent removal of the wedge segments or wedge assembly from the passage. The retainer may be capable of only unidirectional movement towards the front end of the tubular body. The retainer may include a skirt which extends from an annular flange and provides a sliding fit over the rear end of the tubular body.

[0034] The retainer may further be provided with a frangible element carried within the annulus of the flange. The annular flange may be dimensioned to operatively engage the impact surface of the wedge segments around their outer periphery.

[0035] A frangible or tamper evident or removable element may be provided within the annulus and configured to prevent withdrawal of the wedge spacer through the annulus. Engagement of the free end of the cable with the surface of the wedge spacer may permit the wedge spacer to be forced or pushed into engagement with the frangible element. Further movement breaks the frangible element, or dislodges it from the sides of the annulus, and permits removal of the wedge spacer through the annulus. The frangible element may thus provide evidence that the wedge spacer is secured within the passage, or that it may have been tampered with.

[0036] Ratchet formations may be included on the skirt of the retainer. The ratchet formations, which may include inclined annular ribs on an inner surface of the skirt, are configured to cooperate, in use, with complementary formations, which may be circumferential grooves, on the tubular body to permit unidirectional movement of the retainer onto the tubular body. The complementary formations on the tubular body may be located on an outer surface of the tubular body. According to a further aspect of the disclosure there is provided a wedge spacer for use with a set of elongate wedge segments substantially as described above. The wedge spacer is shaped to operatively hold the wedge segments or wedge assembly in the expanded condition and further provides a surface which engages the cable inserted between the wedge segments from the leading or front or free ends thereof and which permits the spacer to be removed or withdrawn through the rear or trailing end of the wedge segments by pushing on the cable. Removal or withdrawal of the spacer permits the wedge segments to be moved to the collapsed condition about the cable.

[0037] The wedge spacer body may include a plurality of arms or spigots configured to extend between adjacent wedge segments to prevent movement towards each other. The arms or spigots may extend in an axial direction from the surface. The surface of the wedge spacer may be provided by a ring, disc or spoke-like elements.

[0038] According to an even further aspect of the disclosure there is provided a retainer for use with a wedge assembly and tubular body substantially as described above and which includes a closure or cap shaped to fit over a rear end of a tubular body and capable of unidirectional movement towards the front end of the tubular body. The closure includes a skirt, which operatively engages over the tubular body, and an inwardly extending annular flange at its end is dimensioned to engage a rear or trailing end of the wedge assembly, preferably towards its periphery and so prevent its removal from the passage. The annulus in the flange permits a cable to be passed therethrough and the retainer thus does not hamper normal operation of the cable anchor.

[0039] Pushing the retainer further onto the body causes it to push the wedge assembly from the expanded condition towards the collapsed condition in the passage. This may obviate the need to use a cable tensioning device or apparatus to so move the wedge segments of the wedge assembly.

[0040] A frangible element is carried internally of the flange, that is to say within the annulus, to prevent withdrawal or removal of a wedge spacer, which is operatively located at the wedge segments, from the flange without breaking or removal of the frangible element. When the free end of the cable meets the surface of the wedge spacer, the spacer is urged or forced or pushed towards the frangible element and further pressure applied to the wedge spacer by the cable then causes the frangible element to break at the connectors. This in turn liberates or frees the frangible element from the retainer and permits withdrawal of the spacer, along with the freed frangible element, from the annulus which then allows the cable to pass through the annulus. The skirt may include tooth or ratchet formations, which may include inclined annular ribs, which cooperate in use with complementary formations, which may be circumferential grooves or ribs, on the tubular body to permit unidirectional movement of the retainer on the body. This may assist in preventing its removal from the body and also provide a visual indication, that cannot be reversed, that the wedge segments have been moved to the collapsed condition.

[0041] An example of a cable anchor securing device 1 is illustrated in Figures 1 to 10. The cable anchor securing device 1 includes a tubular body 10 having a front end 12 and a rear end 14. The body 10 defines an open-ended passage 16. The passage 16 tapers inwardly from a front end 18 of the passage 16, located at a front end 12 of the body 10, towards a rear end 20 of the passage 16, located at a rear end 14 of the body 10, and is configured to operatively receive a cable 2, for example a high tensile cable, therethrough. The free end 4 of the cable 2 is inserted into the front end 18 of the passage 16 and may then be pushed through the passage 16.

[0042] An outer surface 22 of the body 10 includes three circumferential grooves 26 with ribs 28 between the grooves 26, adjacent the rear end 14.

[0043] In this embodiment, three elongate wedge segments 30 of a wedge assembly extend into the passage 16 of the tubular body 10 from the rear end 14 of the passage 16, as shown in Figure 3. Each elongate wedge segment 30 having a leading or front or free end 32 which operatively locates near the front end 12 of the body 10, and a trailing or rear end 34 which operatively locates near the rear end 14 of the body 10.

[0044] The wedge segments 30 are part-circular in cross-section and arranged side-by-side in a generally tubular configuration. A circumferentially extending groove or recess 44 is provided adjacent the trailing end 34 of the wedge segments 30 on the outer surface 42 and operatively receives a wedge retainer (not shown), which may be a spring or spring clip. A passage 38 of generally constant diameter is thus defined between the trailing end 34 and the leading end 32 of the wedge segments 30 through which the cable 2 operatively passes. The outer surface 42 of each wedge segment 30 tapers from the trailing end 34 towards the leading end 32 and is complementary to the taper of the passage 16 of the tubular body 10. A radially extending impact surface 48 is provided at each trailing end 34. In this embodiment, the impact surfaces 48 of the wedge segments 30, when arranged together, provide a generally circular face at the rear end of the wedge assembly.

[0045] The wedge segments 30 are movable between an expanded condition as shown in Figures 2 to 7 and a collapsed condition as shown in Figures 8 to 10. In the expanded condition, the wedge segments 30 are generally circumferentially spaced and a cable 2 can be inserted through the front end 18 of the passage 16 between the leading ends 32 of the wedge segments 30 and through the wedge passage 38. Movement of the wedge segments 30 towards the front end 12 of the tubular body 10 within the passage 16 causes the wedge segments 30 to move to the collapsed condition in which they move radially inwardly and secure about the cable 2 extending between the wedge segments 30. In the collapsed condition the wedge segments 30 are biased by the sides of the tubular body passage 16 into engagement with the cable 2, and space 46 between them is substantially eliminated as the adjacent wedge segments 30 abut. In the expanded condition the cable 2 can slide freely between the wedge segments 30 within the passage 38, whereas in the collapsed condition the cable 2 movement is prevented as result of the cable 2 being gripped by the wedge segments 30 as they constrict or tighten around the cable 2.

[0046] Thus far, apart from the grooves 26, the device 1 is of conventional construction and operates to secure a cable 2 in a known manner.

[0047] According to an aspect of the invention, a wedge spacer is provided and includes a body 62 which is shaped to hold the wedge segments 30 in the expanded condition, as shown in Figures 2 to 7. The wedge spacer further includes a cable contact surface 64 and a retainer contact surface 66 on opposite sides of the body 62.

[0048] In this embodiment 1 , the wedge spacer body 62 is provided by a ring 60 which includes a plurality of circumferentially spaced arms 68 which extend from one side 70 in an axial direction. Each arm 68 extends operatively between respective adjacent wedge segments 30 in the expanded condition. The arms 68 run within the space 46 between adjacent wedge segments 30 from their trailing ends 34 partway to their leading ends 32. Their length corresponds to about two thirds of the length of the wedge segments 30.

[0049] The ends of the arms 68, in this embodiment 1 , are rounded and each has a generally rectangular or trapezoidal cross-section complementary to the shape of the space 46 between the wedge segments 30 such that the sides 72 of the arms 68 abut the sides 54 of the wedge segments.

[0050] In this embodiment, the outer diameter of the ring 60 of the wedge spacer is less than the diameter of the impact surface 48 of the assembled wedge segments, and the inner diameter of the ring 60 is less than the diameter of the cable 2. Also in this embodiment, a retainer 80 is provided which functions to secure the wedge segments 30 within the passage 16. The retainer 80 includes a skirt 82 extending normally from the outer periphery of an annular flange 84. As best shown in Figure 1 , a tubular extension 86 projects axially from the inner periphery of the flange 84 and is radially inwardly stepped 88 partway along its length to provide a shoulder 90.

[0051] A frangible element 96 extends within the open end 94 of the extension 86. In this embodiment, the frangible element 96 is a ring 96 which fits within the open end 94 and has an inner diameter less than the diameter of the body 62 of the wedge spacer 60. The element 96 is secured to the flange 84 by four, circumferentially spaced sprue-like connectors 98 which enable it to be easily removed by axially directed pressure applied to it.

[0052] The skirt 82 has four circumferentially spaced, longitudinal slots 106 extending from its free end 94. The skirt 82 is furthermore a sliding fit over the rear end 14 of the tubular body 10 and has a circumferentially extending rib or tooth 102 at its free end 94. The rib 102 thus extends between the slots 106 and is radially inwardly inclined from the free end 94, terminating in a shoulder 104 which extends normally to the skirt 82. The rib 102 is complementary to the grooves 26 in the outer surface 22 body 10 and these cooperate in use to provide a ratchet which permits only unidirectional movement of the retainer 80 onto the body 10. Thus, the retainer 80 can be pushed onto the body 10, towards the front end 12, but not pulled back towards the rear end 14 or off the tubular body 10.

[0053] The device is supplied ready for use with the rib 94 located in the first groove 26, that is, the groove immediately adjacent the rear end 14 of the body 10.

[0054] The annulus of the flange 84 at the open end 92 is of greater diameter that that of the assembled wedge segments 30, while the extension 86 between the shoulder 90 and flange 84 is dimensioned to engage the impact surfaces 48 of the wedge segments 30 around their respective outer peripheries. The extension 86 from shoulder 90 to its open end 92 has an inner diameter greater than the diameter of the wedge spacer 60.

[0055] The annular flange 84 is further dimensioned such that in the collapsed condition, as shown in Figure 10, the skirt 82 operatively locates around the rear of the tubular body 10 and engages the outer surface 22 of the body 10, and the first shoulder 88 locates adjacent the outer surface 42 of the wedge segments 30 at the groove 44 for the wedge retainer.

[0056] In this embodiment 1 , an indicator 110 is provided on the tubular body 10 which acts as an event indicator to show that an event has occurred, for example that the device or system is experiencing a load above a threshold load. Once the threshold load is surpassed, the indicator will push out from the tubular body. It should be appreciated that this is not essential to the design.

[0057] In use, with the wedge segments 30 held in the expanded condition by the wedge spacer 60, as shown in Figures 2 to 7, the free end 4 of a cable 2 is inserted through a domed washer or base plate 6 located over a hole drilled into a rock body or wall (not shown), the convex side of the base plate 6 facing away from the hole, in a conventional fashion. A cable anchor securing device 1 is then inserted, front end 12 of the tubular body 10 first, over the free end 4 of the cable 2. The cable 2 is able to be fed between the wedge segments 30, as shown in Figure 4, as they are held in the expanded condition and the diameter of the passage 38 between the wedge segments 30 is larger than the diameter of the cable 2. Once the end 4 of the cable 2 engages the cable contact surface 64 of the wedge spacer 60, as shown in Figures 5 and 6, further force is applied, typically by pushing the device 1 further down the cable 2. This causes the wedge spacer 60 to move rearwards in the direction of the frangible element 96 while rearward movement of the wedge segments 30 is prevented by the shoulder 90 of the extension 86.

[0058] Further relative force applied between the cable 2 and device 1 causes the wedge spacer 60 to break the frangible element 96 free from the lip 100. This results in it being possible to use the cable 2 to push the wedge spacer 60 from between the wedge segments 30 and through the lip 100 out the open end 92 of the retainer 80. Hereafter the wedge spacer 60 is removed from the end 4 of the cable 2 and both it and the frangible element 96 discarded or retained for recycling. The removed wedge spacer 60 and / or frangible element 96 may also be used as proof of installation.

[0059] Force operatively applied to the cable contact surface 64 of the wedge spacer 30 by the front or free end 4 of the cable 2 translates into force on the frangible element 96 by the retainer contact surface 66 of the wedge spacer 60. This force causes the frangible element 96 to become dislodged from the lip 100 and break away from it, thereby permitting the frangible element 96 to be removed or released from the retainer 80 along with permitting passage of the free end 4 of the cable 2 through the annulus of the flange 84.

[0060] In order to further tension the device 1 and pre-load the wedge segments 30, the retainer 80 is pushed or urged further over the tubular body 10 in the direction of the front end 12. This in turn pushes the shoulder 90 of the extension 86 against the impact surface 48 of the wedge segments 30 which forces the wedge segments 30 deeper into the passage 16 thus causing the wedge segments 30 to move circumferentially inwardly to tighten around the cable 2. As the retainer 80 is urged further over the tubular body 10, the flange 84 engages the rear end 14 of the tubular body 10, providing a stop position.

[0061] The ratchet formations 102, 104 on the retainer 80 cooperate, in use, with the complementary formations 26, 28 on the tubular body 10 to permit unidirectional movement only of the retainer 80 onto the tubular body 10. The inclined annular ribs 104 move from a first groove 26 closest to the rear end 14 of the tubular body 10 to the second and third groove 26 along the outer surface 22 of the tubular body 10 under force applied to the retainer 80. Once the ribs 104 reach the final groove 26 on the tubular body closest to the front end 12, the wedge segments 30 are sufficiently pre-loaded. This holds the wedge segments 30 in place in the collapsed and pre-loaded condition as shown in Figure 10. In this manner the cable 2 is secured under tension in the hole (not shown) and slippage of the cable 2 prevented.

[0062] The cable 2 is then secured in a cable tensioning apparatus (not shown), and fully tensioned in conventional manner.

[0063] The advantages provided by the cable anchor device 1 include that the wedge spacer prevents the wedge segments collapsing and preventing insertion of the cable into the device with the wedge segments in position in the passage. The device can thus be supplied with the wedge segments in place rather than requiring them to be separately supplied and installed over a cable. This greatly simplifies logistics and installation time. Also, the retainer ensures that the wedge segments cannot fall out of the body or be removed from it without breaking the retainer. The retainer thus provides visual evidence of the integrity of the device, that is to say that the wedge segments are in position in the body. The retainer further ensures that the device cannot be tampered with without breaking it.

[0064] The ability of the retainer to pre-tension the device also ensures that it cannot easily fall off the cable prior to full tensioning. Such occurrences result in a waste of time and often the loss of the device as operators often find it more convenient to simply fit a new device than looking for a fallen device, especially where there are rocks or other debris around.

[0065] Further advantages include that the wedge spacer and frangible element can be used as proof of installation. This enables the efficiency of operations to be tracked, and also collated to the number of cable anchors installed.

[0066] The configuration of the device 1 permits simple one-handed operation that allows the assembly or device 1 to be slid onto the cable with minimal effort until the wedge spacer has been freed. This then creates an instant grip effect on the cable that prevents the device from being removed in the opposite direction thus providing an anti-pull back mechanism.

[0067] The wedge spacer of this embodiment 1 , which comprises a ring having a plurality of arms axially extending therefrom, saves material and lowers production costs.

[0068] It will be appreciated, however, that many other embodiments exist especially with regard to the wedge spacer and retainer.

[0069] For example, in a further embodiment (not shown), the wedge spacer may be provided by a disc, or pair of discs carried on opposite ends of an axially extending stem, or other insert shaped to hold the wedge segments in the expanded condition. The diameter of the disc may be larger than the diameter of the cable such that it holds the wedge segments in the expanded condition and allows the cable to slide freely within the wedge passage. Engagement of the disc by the free end of the cable inserted between the wedge segments from the front end of the passage may urge the disc towards the trailing ends of the wedge segments permitting its removal from the rear end of the wedge segments. The disc or insert may be triangular, circular, square, or any other suitable shape capable of holding the wedge segments in the expanded condition. Some embodiments may include a single insert carried on the stem, while other embodiments may include a set of three of more inserts or discs carried on a plurality of stems. In some embodiments (not shown), the wedge spacer disc or insert may have arms or spigots extending therefrom into the slots or grooves between the wedge segments.

[0070] In other embodiments (not shown), the wedge spacer may be provided by a circular, triangular, or any other suitably shaped tube capable of holding the wedge segments in the expanded condition, and having an inner diameter less than that of the cable so that the cable can engage it and push it rearwards.

[0071] In some embodiments (not shown), the inner surface of the wedge segments may include a gripping formation such as teeth, grooves, ridges, texture, rubberised texture, knurling, or the like, on substantially the entire or a part of the inner surface. The outer surface of each wedge segment may be substantially smooth to facilitate sliding along the inner surface of the body defining the passage.

[0072] In some further embodiments (not shown) the wedge spacer may be provided by a ring having a plurality of spigots extending from a surface or side thereof and configured to extend between adjacent wedge segments to maintain them in a properly spaced arrangement. The foregoing description has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the technology to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure.

[0073] The language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the present disclosure be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the present disclosure is intended to be illustrative, but not limiting, of the scope of any accompanying claims.

[0074] Finally, throughout the specification and any accompanying claims, 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.

Claims

CLAIMS:1 . A cable anchor securing device which includes a tubular body defining a passage therethrough from a front end to a rear end with the passage tapering from the rear end to the front end, and a plurality of elongate wedge segments inserted in the rear end of the passage, the wedge segments each having a leading end and a trailing end with a radially extending impact surface provided at each trailing end, and the wedge segments movable in the passage to be operable between an expanded condition in which the wedge segments are generally circumferentially spaced and a cable operatively extending through the passage can be inserted between the leading ends of the wedge segments, and a collapsed condition in which movement of the wedge segments towards the front end of the tubular body within the tapered passage causes the wedge segments to move radially inwardly and secure about the cable extending therebetween, characterised in that a wedge spacer is provided which is shaped to hold the wedge segments in the expanded condition and further providing a surface which is engageable by a free end of the cable inserted between the wedge segments from the front end of the passage and to permit removal of the spacer from the rear end of the wedge segments.

2. The cable anchor securing device as claimed in claim 1 , in which a retainer is provided over the rear end of the tubular body and capable of unidirectional movement towards the front end of the tubular body, the retainer including a skirt providing a sliding fit over the rear end of the tubular body and which extends from an annular flange, the annular flange dimensioned to engage the impact surface of the wedge segments around their outer periphery, the annulus dimensioned to permit withdrawal of the wedge spacer therethrough.

3. The cable anchor securing device as claimed in claim 2, which includes a frangible element carried within the annulus of the flange to prevent withdrawal of the wedge spacer through the annulus.

4. The cable anchor securing device as claimed in claim 2 or claim 3, in which the skirt includes ratchet formations which cooperate in use with complementary formations on the tubular body to permit unidirectional movement of the retainer onto the tubular body.

5. The cable anchor securing device as claimed in claim 4, in which the ratchet formations include inclined annular ribs which cooperate with circumferential grooves in the tubular body.

6. The cable anchor securing device as claimed in any one of the preceding claims, in which the wedge spacer includes a plurality of arms extending in an axial direction from the surface and each arm shaped to extend between respective adjacent wedge segments.

7. A wedge spacer for use with a set of elongate wedge segments held together at a rear end and movable between an expanded condition in which a cable can be inserted through the free ends of the wedge segments, and a collapsed condition in which the free ends of at least some of the wedge segments abut, the wedge spacer including a body shaped to operatively hold the wedge segments in the expanded condition and further providing a surface which engages the cable inserted between the wedge segments from the free ends thereof and which permits withdrawal of the spacer from the rear end of the wedge segments.

8. The wedge spacer as claimed in claim 7, in which the body includes a plurality of arms extending in an axial direction from the surface and each arm shaped to extend between respective adjacent wedge segments.

9. The wedge spacer as claimed in claim 7 or claim 8, in which the surface is provided by a ring having an inner diameter less than that of the periphery of the rear end of the wedge segments.

10. The wedge spacer as claimed in claim 8 or claim 9, in which the arms extend between the wedge segments.

11. A retainer for a wedge spacer which includes a closure shaped to fit over a rear end of a wedge assembly operatively received within a passage defined by a tubular body, the retainer capable of unidirectional movement towards the tubular body to urge the wedge assembly deeper into the passage, the closure including a skirt and an inwardly extending flange at its end, the flange dimensioned to engage the rear end of the wedge assembly around their periphery with a frangible element carried internally of the flange to prevent withdrawal of the wedge spacer from the flange without removal of the frangible element.

12. The retainer for a wedge spacer as claimed in claim 11 , in which the skirt includes ratchet formations which cooperate in use with complementary formations on the tubular body to permit unidirectional movement of the retainer onto the tubular body.

13. The retainer for a wedge spacer as claimed in claim 12, in which the ratchet formations include inclined annular ribs which cooperate with circumferential grooves in the tubular body.

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