Rock Bolt

Abstract

A rock bolt well adapted for use in mining is provided. The rock bolt includes an anchor tube that encloses an interior space, a fixing agent arranged inside the interior space for the substance-to-substance fixation of the anchor tube to stone, a mobile piston arranged inside the interior space for transporting the fixing agent out of the anchor tube when the anchor tube is arranged in a bore hole in the stone, a piston moving mechanism, an anchor nut, and an anchor plate supported by the anchor nut for support on the stone.

1 . A rock bolt comprising:
 an anchor tube that encloses an interior space;   a fixing agent initially arranged inside the interior space of the anchor tube, the fixing agent configured to provide a substance-to-substance fixation of the anchor tube to stone into which the anchor tube is inserted,   a mobile piston arranged inside the interior space of the anchor tube, the mobile piston configured to transport the fixing agent out of the anchor tube;   an anchor nut;   an anchor plate supported by the anchor nut, the anchor plate configured to support the stone into which the rock bolt is inserted; and   a piston moving mechanism configured to move the mobile piston, the piston moving mechanism comprising a spindle drive.   
     
     
         2 . A rock bolt according to  claim 1  wherein the anchor nut and the anchor plate are fastened at a rod arranged inside the anchor tube, the rod being fastened via a fastening device at the anchor tube such that the fastening of the rod at the anchor tube is only released beginning at a predetermined tensile force in the rod, whereby the rod can be partially moved outwardly so that the rock bolt comprises a gliding anchor. 
     
     
         3 . A rock bolt according to  claim 1 , comprising a threaded rod and a fastening device, the threaded rod comprising an external thread, the fastening device comprising an annular part with an internal thread, wherein the annular part is fastened at the anchor tube and the internal thread of the annular part engages the external thread of the threaded rod. 
     
     
         4 . A rock bolt according to  claim 3 , wherein the internal thread of the annular part is located inside of the anchor tube. 
     
     
         5 . A rock bolt according to  claim 3 , wherein the internal thread of the annular part comprises a specialty thread which destroys the external thread of the threaded rod beginning at a predetermined tensile force. 
     
     
         6 . A rock bolt according to  claim 1 , wherein the spindle drive comprises a threaded rod and an annular part with an internal thread, the internal thread engaging the threaded rod. 
     
     
         7 . A rock bolt according to  claim 6 , wherein the mobile piston is fastened directly or indirectly to the threaded rod. 
     
     
         8 . A rock bolt according to  claim 1 , wherein a rear end of the anchor tube is closed by a cap, and at least one of the anchor tube and the cap comprises at least one opening to guide the fixing agent from the interior space enclosed by the anchor tube. 
     
     
         9 . A rock bolt according to  claim 1 , wherein the fixing agent comprises an adhesive component and a curing component. 
     
     
         10 . A rock bolt according to  claim 9 , wherein the adhesive and curing components are each arranged in separate bags. 
     
     
         11 . A rock bolt according to  claim 1 , wherein a mixer is arranged between the fixing agent and at least one opening of the anchor tube, the mixer configured to mix the fixing agent prior to the emission of the fixing agent from at least one opening. 
     
     
         12 . A rock bolt according to  claim 5  wherein the threaded rod comprises a stop positioned and configured to limit the ability of the threaded rod to move outwardly. 
     
     
         13 . A method for fixing a rock bolt comprising the steps of:
 implementing a bore hole into stone;   inserting the rock bolt into the bore hole;   transporting a fixing agent from an interior space enclosed by an anchor tube of the rock bolt through at least one opening into a space between the anchor tube and the stone by moving a piston in the interior space towards the fixing agent, wherein the piston is moved via a spindle drive of the rock bolt;   fastening of the anchor tube to the stone with the fixing agent; and,   allowing the fixing agent to cure.   
     
     
         14 . A method according to  claim 13 , wherein the spindle drive comprises a threaded rod, and wherein moving the piston comprises applying a torque upon the threaded rod from the outside such that the threaded rod is set into a rotary motion about a longitudinal axis of the threaded rod and the threaded rod is screwed with an external thread to an internal thread proximate to the anchor tube so that by the threaded rod an axial motion is performed inwardly such that the threaded rod is screwed into the interior space enclosed by the anchor tube. 
     
     
         15 . A method according to  claim 14 , wherein the piston is fastened at the threaded rod and performs an axial motion directed inwardly together with the threaded rod. 
     
     
         16 . A method according to  claim 14 , wherein prior to screwing the threaded rod inwardly into the anchor tube, the threaded rod is only partially arranged in the interior space enclosed by the anchor tube, and during the transporting of the fixing agent out of the interior space enclosed by the anchor tube the threaded rod is essentially screwed entirely into the interior space enclosed by the anchor space.