Yielding Spiral Bolt Appendage for a Rock Bolt

Abstract

A yielding spiral holt appendage for attachment to a rock holt has a cylindrical shank portion for attachment to the insertion end or the rock and a helical flute portion having a tip for rupturing a resin cartridge and achieving mixing when rotated. The shank has a first tapered portion and a second tapered portion for resisting movement or the appendage once the resin has set.

1 . A yielding spiral bolt appendage for attachment to a rock bolt insertion end for placement into a predrilled hole containing a resin system, said spiral bolt appendage comprising a body having a shank portion for attachment to said rock bolt insertion end and a helical tinted portion for acting on said resin system, wherein the resin system comprises an at least one resin cartridge. 
     
     
         2 . The appendage of  claim 1  wherein said body is cast so that said shank portion is integral with said helical fluted portion. 
     
     
         3 . The appendage of  claim 1  wherein said body is forged. 
     
     
         4 . The appendage of  claim 1  wherein the helical fluted portion is welded to the shank portion. 
     
     
         5 . The appendage of  claim 1  wherein the helical fluted portion comprises an at least one-half pitch helix and a tip for piercing the at least one resin cartridge and wherein the helical fluted portion is rotated to achieve mixing of the resin within said predrilled hole resulting in set resin around the body. 
     
     
         6 . The appendage of  claim 1  wherein the shank portion is cylindrical and comprises a top end, a bottom end and an apex between said top end and said bottom end. 
     
     
         7 . The appendage of  claim 6  wherein the shank portion further comprises a first taper from said apex to the shank top end and a second taper from the apex to the shank bottom end. 
     
     
         8 . The appendage of  claim 7  wherein said first taper acts on said set resin to resist inward movement of the rock bolt and wherein said second taper acts on the set resin to resist outward movement of the rock bolt. 
     
     
         9 . The appendage of  claim 8  wherein the shank further includes a bore having a closed end and an open end for receiving the insertion end of the rock bolt. 
     
     
         10 . The appendage of  claim 7  wherein the shank portion is welded to the insertion end of the rock bolt. 
     
     
         11 . The appendage of  claim 9  wherein said bore includes in threaded inside surface for threaded attachment with the insertion end of the rock bolt. 
     
     
         12 . A rock bolt assembly comprising a tension member comprising a threaded insertion end for insertion into a predrilled hole into a face of a rock formation and a threaded opposite end exposed out of said predrilled hole, said threaded opposite end having a threaded nut attached thereto and a hearing plate forward of said threaded nut, said threaded nut attachable to a omitting machine for rotation towards said face so that said hearing plate is in contact with the face for tensioning the tension member, wherein said rock bolt assembly further comprises a yielding spiral bolt appendage attached to the insertion end of the rock bolt. 
     
     
         13 . The rock bolt assembly of  claim 12  wherein said yielding spiral bolt appendage is threaded onto the insertion end of the rock bolt. 
     
     
         14 . The rock bolt assembly of  claim 12  wherein the yielding spiral bolt appendage is welded onto the insertion end of the rock bolt. 
     
     
         15 . The rock bolt assembly of  claim 12  wherein the yielding spiral bolt appendage comprises a shank portion having a top end and a bottom end and an apex between said top end and said bottom end and comprising a first taper from said apex to said shank top end and a second taper from the apex to said shank bottom end. 
     
     
         16 . A rock bolting system comprising at least one resin cartridge for placement into a predrilled hole into a face of rock formation a tension member comprising a threaded insertion end for insertion into said predrilled hole and a threaded opposite end exposed out of said predrilled hole, said threaded opposite end having a threaded nut attached thereto and a bearing plate forward of said threaded nut, said threaded nut attachable, to a rotating machine for rotation towards said face so that said bearing plate is in contact with the face for tensioning the tension member, wherein said rock bolt assembly further comprises a yielding spiral bolt appendage for threaded attachment to the insertion end of the rock bolt, wherein said yielding spiral bolt comprises a tip for piercing said resin cartridge and a fluted portion for mixing the resin until the resin sets around the yielding spiral bolt appendage. 
     
     
         17 . The rock bolting system of  claim 16  wherein the yielding spiral bolt appendage comprises a shank portion having a top end and a bottom end and an apex between said top end and said bottom end and comprising a first taper from said apex to said shank top end and a second taper from the apex to said shank bottom end. 
     
     
         18 . The rock bolting system of  claim 17  wherein said first taper acts on said set resin to resist inward movement cit the rock bolt and wherein said second taper acts on said set resin to resist outward movement of the rock bolt.