[0001] This invention relates to a device that will assist in optimally positioning a resin cartridge in a rock hole.

[0002] Hereinafter, the term "resin" and "grout" are used interchangeably to refer to a material that aids in adhering the rock bolt into the rock hole.

[0003] Hereinafter, the term "capsule" and "cartridge" are used interchangeably to refer to a membraneous encasement to a resin or grout material.

[0004] In a typical grouted rock bolt installation, a plurality of resin capsules are inserted into a rock hole in advance of the rock bolt.

[0005] A problem occurs when the rock bolt is significantly shorter than the depth of the rock hole. Coupled to this, resin capsules often bunch at the head of the rock hole when inserted. When the rock bolt is finally pushed up the hole, many of the resin capsules lie beyond the reach of the tip of the rock bolt and therefore will not be punctured, mixed or destructed. This will result in a section of the bolt being unbonded. This typically occurs in the region towards the mouth of the rock hole.

[0006] The solution to this has been to place, into the rock hole, more resin capsules than what is typically needed if the rock bolt was of sufficient length. This has a cost consequence.

[0007] The present invention seeks to at least partially address the above problems. SUMMARY OF INVENTION

[0008] The invention provides a positioning device for positioning a resin cartridge within a rock hole which includes a cartridge holding means comprised of a hollow cup-like body which extends between an apical end an open mouth end and an elongate spacer which engages with the holding means, extending axially from the apical end of the body.

[0009] The hollow cup-like body may be made of a resiliently deformable material, like, for example, a rubber or plastics material.

[0010] The body may include a plurality of gripping formations formed on an inner surface of the body.

[0011] The gripping formations may be radially spaced on the inner surface, adjacent the mouth end.

[0012] Each gripping formation may be wedge shaped.

[0013] The apical end has an opening and the elongate spacer engages the holding means by pushing through the opening to enable the elongate spacer to move axially relatively to the holding means.

[0014] The elongate spacer may have a solid cylindrical rod-like body.

[0015] The rod-like body may be made of a resiliently deformable material such as a rubber or rubber-like material. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention is further described by way of example with reference to the accompanying drawings in which:

Figure 1 is an isometric view of a resin cartridge positioner in accordance with the invention;

Figure 2 is a view in longitudinal section of the resin cartridge positioner of Figure 1 ; Figure 3, 4 and 5 diagrammatically illustrate the steps to inserting the resin cartridge positioner into a rock hole, with a resin cartridge engaged with a positioner in use.

DESCRIPTION OF PREFERRED EMBODIMENT

[0017] Figures 1 and 2 of the accompanying drawings illustrates a resin cartridge positioner 10 in accordance with the invention. The positioner includes a resin cartridge gripping cap 12 and an elongate spacer 14 apically extending from the cap.

[0018] The cap 12, in the preferred embodiment, has a hollow conical shaped body 16, made of a resiliently deformable material such as a plastics material, which has an apical end 18 and an opposed open mouth end 20 which opens into a cavity 22.

[0019] The spacer 14 extends from the apical end in longitudinal alignment. The spacer has a solid cylindrical rod-like body 24 again of a resiliently deformable material such as a rubber or rubber-like material. The rod-like body extends between a distal end 26 and a proximal end 28. The length of the spacer body is predetermined based on the length of the rock bolt to be used and the depth of the rock hole in which the rock bolt is inserted. [0020] In the preferred embodiment, the apical end 18 of the cap 12 is open to receive a proximal end portion 30 of the spacer body 24 with the proximal end 28 being formed to be diametrically larger than the rest of the body so as to prevent pull through of the body from the open apical end 1 6. In this configuration, the spacer 14 can move axially relatively to the cap to adjust the depth at which a resin cartridge is suspended within a rock hole.

[0021] The gripping cap 12 has a plurality of evenly radially spaced wedged-shaped gripping formations 32 formed on its inner surface, adjacent the mouth end 20. Each of the gripping formations taper inwardly from the mouth 20. [0022] Use of the positioner 10 is illustrated in Figures 3 to 5. In a first step, illustrated in Figure 3, one end of a resin cartridge 34 is inserted partially into the cavity 22, held frictionally in place within the mouth end 20, by the gripping formations 32. An insertion tube 36 is placed over a projecting portion of the resin cartridge to contact the mouth end as is illustrated. This assembly is now ready for insertion.

[0023] The positioner 10 is placed at the mouth of a hole 38 with the distal end 26 of the spacer body 24 leading, and, using the insertion tube 36, the positioner is pushed into the hole. The conical body 16 of the cap 12 is slightly diametrically larger than the diameter of the hole. Thus, the walls of the body will move resiliently inwardly to accommodate the inward movement.

[0024] Once the distal end 26 of the spacer 14 engages the end 40 of the rock hole, the installer is assured that the resin cartridge is placed at an optimal depth within the hole. The spacer body length is specifically chosen based on, as mentioned earlier, the rock bolt length and rock hole depth.

[0025] The insertion tube 36 is then retracted from the hole 38 and the positioner 10 is held up within the hole, by the frictional engagement of the resiliently deformable conical body 24 of the cap with the walls of the hole which prevents the positions from slipping down the hole. This step is illustrated in Figure 4. Minor adjustments to the cartridge's position can be made by adjusting the position of the cap relatively to the spacer.

[0026] Finally, a rock bolt 44 is inserted into a rock hole with a penetrating leading end 46 of the rock bolt piercing the suspended resin cartridge 34, allowing release its resin content. This optimal positioning of the resin cartridge within the rock hole is made possible by the positioner 10. However, if the resin cartridge is not optimally located form some reason, for example due to a shorter than expected rock hole, the positioner will not resist the upward movement of the rock bolt into the rock hole, which would be the case if the spacer was not resiliently deformable. In such a situation, the spacer body 24 will give way by resilient deformation, as illustrated in dotted outline in Figure 5, allowing unhindered insertion of the bolt into the hole.

[0027] Due to the shape of the cap, once the resin cartridge is severed by the rock bolt, the resin will only flow downwardly, prevented from upward movement towards the head of the hole by the umbrellaed barrier of the cap.