Drill Bit for Use with a Friction Bolt

Abstract

A drill bit for a drill assembly including a friction bolt defining a longitudinal axial passage, the drill bit being adapted to be releasibly attached to the friction bolt and comprising: (i) a leading end including a cutting part; (ii) a following end; and (iii) an outer surface defining a friction bolt engaging means adapted to releasibly engage with the leading end of the friction bolt.

1 - 44 . (canceled) 
     
     
         45 . A drill bit for a drill assembly including a friction bolt defining a longitudinal axial passage, the drill bit being adapted to be releasibly attached to the friction bolt and comprising:
 (i) a leading end including a cutting part;   (ii) a following end; and   (iii) an outer surface defining a friction bolt engaging means adapted to releasibly engage with the leading end of the friction bolt.   
     
     
         46 . The drill bit according to  claim 45 , wherein the friction bolt engaging means is adapted to releasibly engage with a portion of the inside lip of the leading end of the friction bolt. 
     
     
         47 . The drill bit according to  claim 45 , wherein the friction bolt engaging means comprises at least one recess. 
     
     
         48 . The drill bit according to  claim 47 , wherein the recess is located approximately halfway between the leading and trailing ends. 
     
     
         49 . The drill bit according to  claim 47 , wherein the recess comprises a channel member. 
     
     
         50 . The drill bit according to  claim 45 , and further comprising a ring or cylinder shaped body. 
     
     
         51 . The drill bit according to  claim 45 , and further comprising a tapered outer surface that tapers in towards its leading end. 
     
     
         52 . The drill bit according to  claim 45 , and further comprising a socket extending at least partially between its leading end and its trailing end. 
     
     
         53 . The drill bit according to  claim 52 , wherein the socket comprises a tapered socket. 
     
     
         54 . The drill bit according to  claim 53 , wherein the tapered socket tapers in towards its leading end. 
     
     
         55 . A drill bit assembly for use with a drill assembly including a friction bolt defining a longitudinal axial passage, the drill bit comprising:
 (i) a drill bit according to  claim 45 ; and   (ii) a drive member adapted to pass through the longitudinal axial passage in the friction bolt when the friction bolt is in situ;   wherein the drill bit and the drive member are adapted to be releasibly engaged with each other.   
     
     
         56 . The drill bit assembly according to  claim 55 , wherein the drill bit and the drive member are releasibly engaged via a taper fit. 
     
     
         57 . The drill bit assembly according to  claim 55 , wherein the drive member comprises a second drill bit. 
     
     
         58 . The drill bit assembly according to  claim 57 , wherein the second drill bit comprises a tapered shank that tapers in towards its leading end. 
     
     
         59 . The drill bit assembly according to  claim 57 , wherein the drill bit and the second drill bit releasably engage to form an integral cutting surface. 
     
     
         60 . The drill bit assembly according to  claim 57 , further comprising an abutment means that is positioned to ensure the engagement between the first and second drill bits functions optimally when the drill bit assembly is in use. 
     
     
         61 . A drill string assembly comprising:
 (i) a drill string;   (ii) a drill bit assembly according to  claim 56  mounted on the leading end of the drill string; and   (iii) a friction bolt defining a longitudinal axial passage.   
     
     
         62 . A friction bolt, defining a longitudinal axial passage, comprising a drill bit according to  claim 45 , releasably engaged therewith. 
     
     
         63 . A method for inserting a friction bolt according to  claim 62  into a formation comprising the steps of:
 (i) providing the friction bolt; 
 (ii) fitting said friction bolt to a drill string assembly; 
 (iii) drilling a hole in the formation using the drill string assembly wherein said drilling results in the insertion of the friction bolt; 
 (iv) disengaging the drill bit and the friction bolt from the drill string; and 
 (v) retrieving the drill string from the hole, through a longitudinal axial passage in the friction bolt. 
 
     
     
         64 . The method according to  claim 63 , wherein the drilling of the hole and insertion of the friction bolt occurs in a single pass or simultaneously.