Self-drilling rock anchor

Abstract

A self-drilling rock anchor includes a drilling head ( 16; 46 ) provided at one end ( 13 ) of the receiving body ( 12 ), an inner tube ( 21 ) for receiving a pressurable-out hardenable mass ( 26 ) and provided in the receiving body ( 12 ) and having an outlet opening ( 22 ) spaced from the drilling head ( 16; 46 ), and a mixing member ( 31; 61 ) displaceably supported in the inner tube ( 21 ), with the drilling head ( 16; 46 ) having a receptacle ( 18; 48 ) adjacent to the mixing member ( 31; 61 ) for receiving a free end ( 32; 62 ) of the mixing member ( 21; 61 ) and a through-opening ( 17 ) for the hardenable mass ( 26 ), and the receptacle ( 18; 48 ) of the drilling head ( 16; 46 ) having a centering section ( 20; 50 ) that cooperates with a counter-centering section ( 33; 63 ) provided at the free end ( 32; 62 ) of the mixing member ( 31; 61 ) adjacent to the drilling head ( 16; 46 ).

1 . A self-drilling rock anchor ( 11 ;  41 ), comprising:
 a hollow cylindrical receiving body ( 12 );   a drilling head ( 16 ;  46 ) provided at one end ( 13 ) of the receiving body ( 12 );   an inner tube ( 21 ) for receiving a pressurable-out hardenable mass ( 26 ) and provided in the receiving body ( 12 ) and having an outlet opening ( 22 ) spaced from the drilling head ( 16 ;  46 );   a mixing member ( 31 ;  61 ) displaceably supported in the inner tube ( 21 ), the drilling head ( 16 ;  46 ) having a receptacle ( 18 ;  48 ) adjacent to the mixing member ( 31 ;  61 ) for receiving a free end ( 32 ;  62 ) of the mixing member ( 21 ;  61 ) and a through-opening ( 17 ) for the hardenable mass ( 26 ), and the receptacle ( 18 ;  48 ) of the drilling head ( 16 ;  46 ) having a centering section ( 20 ;  50 ) that cooperates with a counter-centering section ( 33 ;  63 ) provided at the free end ( 32 ;  62 ) of the mixing member ( 31 ;  61 ) adjacent to the drilling head ( 16 ;  46 ).   
   
   
       2 . A rock anchor according to  claim 1 , wherein the centering section ( 20 ) of the receptacle ( 18 ) of the drilling head ( 16 ) has a funnel shape and tapers toward the free end of the drilling head ( 16 ). 
   
   
       3 . A rock anchor according to  claim 1 , wherein a wall section of the centering section ( 50 ) that surrounds the receptacle ( 48 ) of the drilling head ( 46 ) is formed concave. 
   
   
       4 . A rock anchor according to  claim 1 , wherein a wall section of the counter-centering section ( 63 ) that surrounds the end region of the free end of the mixing member ( 61 ) is formed convex. 
   
   
       5 . A rock anchor according to  claim 1 , wherein the centering section ( 20 ;  50 ) of the receptacle ( 18 ;  48 ) of the drilling head ( 16 ;  46 ) has a diameter (D 1 ; D 2 ) larger than a diameter (d 1 , d 2 ) of the counter-centering section ( 33 ;  63 ) of the free end ( 32 ;  62 ) of the mixing member ( 31 ;  61 ). 
   
   
       6 . A rock anchor according to  claim 1 , wherein the counter-centering section ( 63 ) is formed of several centering elements ( 64 ) formed at the free end ( 62 ) of the mixing member ( 61 ). 
   
   
       7 . A rock anchor according to  claim 6 , wherein the centering elements ( 64 ) are arranged rotationally symmetrically with respect to a longitudinal axis ( 23 ) of the inner tube ( 21 ). 
   
   
       8 . A rock anchor according to  claim 1 , further comprising a stop ( 19 ;  49 ) for the mixing member ( 31 ;  61 ) provide din the receptacle ( 18 ;  48 ) of the drilling head ( 16 ;  46 ).