Bolt assembly

Abstract

A bolt assembly for insertion into a rock wall including a hole having a diameter an a method thereof are provided. The assembly includes a resilient cylinder for insertion into the hole, a shaft for insertion into the cylinder, a grouting material for retaining the shaft within the cylinder and stiffening the assembly, and coupling means for coupling the extremity of the cylinder to the extremity of the shaft. The cylinder has a diameter which is greater than the diameter of the hole when the cylinder is uncompressed. In this manner, the cylinder is radially compressed when inserted into the hole and thereby frictionally engages the hole. The cylinder has an extremity extending outside the hole when it is inserted therein. The shaft includes an extremity which extends outside the hole when the shaft is inserted into the cylinder in an operating position.

1 . A bolt assembly for insertion into a rock wall comprising a hole having a diameter, the assembly comprising:
 a) a resilient cylinder for insertion into the hole, the cylinder having a diameter which is greater than the diameter of the hole when the cylinder is uncompressed so that the cylinder is radially compressed when inserted into the hole and thereby frictionally engages the hole, the cylinder having an extremity extending outside the hole when the cylinder is inserted into the hole;   b) a shaft for insertion into the cylinder, the shaft comprising an extremity which extends outside the hole when the shaft is inserted into the cylinder in an operating position;   c) a grouting material for retaining the shaft within the cylinder and stiffening the assembly; and   d) coupling means for coupling the extremity of the cylinder to the extremity of the shaft.   
   
   
       2 . The bolt assembly of  claim 1 , wherein the shaft comprises a threaded portion proximate its extremity and the coupling means comprises a correspondingly threaded portion such that the coupling means is screwable along the shaft in the operating position to couple the extremity of the cylinder to the extremity of the shaft. 
   
   
       3 . The bolt assembly of  claim 2 , further comprising a plate capable of being positioned around the shaft between the coupling means and the extremity of the cylinder. 
   
   
       4 . The bolt assembly of  claim 2 , further comprising a plate capable of being positioned around the cylinder proximate to the cylinder's extremity for contact with the rock wall. 
   
   
       5 . The bolt assembly of  claim 1 , wherein the shaft comprises external ridges. 
   
   
       6 . The bolt assembly of  claim 1 , wherein the grouting material is a resin contained in a cartridge, the cartridge being positioned within the cylinder and punctured by the shaft during its insertion into the cylinder. 
   
   
       7 . The bolt assembly of  claim 6 , wherein the resin is a multi-part resin contained in separate chambers of the cartridge, the chambers being punctured by the shaft during its insertion into the cylinder, thereby mixing the multi-part resin and initiating the curing thereof. 
   
   
       8 . The bolt of  claim 1 , wherein the cylinder further comprises a longitudinal opening extending its length. 
   
   
       9 . A method of installing a bolt assembly in a rock wall comprising a hole having a diameter, the method comprising the steps of:
 a) providing a compressible cylinder having a diameter which is greater than the diameter of the hole when the cylinder is uncompressed;   b) inserting the cylinder into the hole until an extremity of the cylinder remains outside the hole, thereby compressing the cylinder such that the cylinder frictionally engages the hole;   c) inserting a shaft into the cylinder until an extremity of the shaft remains outside the cylinder;   d) providing a grouting material for retaining the shaft within the cylinder and stiffening the assembly; and   e) coupling the extremity of the cylinder and the extremity of the shaft with a coupling means.   
   
   
       10 . The method of  claim 9 , wherein step a) comprises a step of inserting a resin cartridge into the cylinder prior to step b), and step c) comprises a step of puncturing the cartridge by means of the shaft. 
   
   
       11 . The method of  claim 9 , wherein:
 in step b) the shaft comprises a threaded portion proximate to its extremity;   in step e) the coupling means comprises a correspondingly threaded portion; and   step e) further comprises the step of screwing the coupling means along the shaft to couple the extremity of the cylinder to the extremity of the shaft.