Re-tensionable cable bolt apparatus and related method
View Patent ↗A re-tensionable cable bolt and related methods are provided. In one aspect of the invention, the bolt includes a sleeve for connecting or securing to a cable. The sleeve includes a lower end having a bore adapted for receiving a threaded shank for associating with a tension nut. A plurality of facets along a peripheral portion of the sleeve create corners that prevent the cable from rotating within the borehole during installation. The sleeve may be secured to the cable using resin, which forms another aspect of the invention.
1. An apparatus for installation in a borehole formed in a stratum creating a face of a mine passage in association with a cable, comprising:
an elongated sleeve for receiving and securing one end of the cable, said sleeve having a lower end including an internally threaded bore for receiving a threaded shank and a plurality of facets along a peripheral portion forming corners adapted for engaging the stratum within the borehole during installation of the lower end in the borehole.
2. The apparatus of claim 1 , wherein the bore extends entirely through the sleeve and includes an undersized portion for engaging an oversized portion of the cable.
3. The apparatus of claim 2 , further including resin within the bore for connecting the cable to the sleeve.
4. The apparatus of claim 3 , wherein the sleeve includes a transverse channel for injecting the resin into the bore.
5. The apparatus of claim 1 , wherein the plurality of facets are arranged to provide the peripheral portion with a cross section forming a regular polygon.
6. The apparatus of claim 1 , wherein at least two of the corners are spaced apart a distance greater than a diameter of the borehole.
7. An apparatus for installation in a borehole having a diameter formed in a face of a mine passage, comprising:
an elongated cable for extending into the borehole, said cable having an oversized portion; and
a sleeve having a bore for receiving the oversized portion of the cable and resin located within the sleeve for securing the cable to the sleeve.
8. The apparatus of claim 7 , wherein a peripheral portion of the sleeve includes a plurality of facets.
9. The apparatus of claim 8 , wherein the facets provide the peripheral portion of the sleeve with a cross-section forming a regular polygon.
10. The apparatus of claim 7 , wherein the bore includes an internally threaded portion for receiving a threaded shank carrying a tension nut.
11. The apparatus of claim 7 , wherein the resin holds the oversized portion of the cable within the bore.
12. A method of forming a bolting apparatus for insertion in a borehole formed in a mine passage, comprising:
inserting an oversized portion of a cable into a bore of a sleeve; and
securing the oversized portion of the cable within the sleeve, including by using resin located within the sleeve;
whereby the resin when cured or hardened securely holds the oversized portion of the cable within the sleeve during tensioning.
13. The method of claim 12 , further including the step of snugging the oversized portion of the cable against an undersized portion of the bore.
14. The method of claim 12 , wherein the securing step comprises injecting the resin comprising a two-component resin into the bore adjacent the oversized portion of the cable.
15. The method of claim 12 , further including the step of inserting a threaded shank into the sleeve.
16. A method of installing a cable bolt in a borehole formed in a mine passage, comprising:
securing a cable to a sleeve having an oversized portion relative to the borehole wherein the diameter of the sleeve is greater than the diameter of the borehole wall;
securing the cable and the sleeve within the borehole with the oversized portion in engagement with an adjacent strata; and
inserting a threaded shank into an internal bore formed in the sleeve.
17. The method of claim 16 , further including the step of tensioning the bolt by advancing a tension nut along the threaded shank.
18. The method of claim 16 , wherein the oversized portion of the sleeve includes a plurality of facets creating corners, and the securing step includes inserting the oversized portion of the sleeve within the borehole.
19. The method of claim 16 , wherein the securing step includes grouting the cable in the borehole.
20. The method of claim 16 , wherein the securing step comprises using grout or resin to secure the oversized portion of the cable to the sleeve.