One-piece drill bit for single-pass anchor bolting and single pass drilling apparatus

Abstract

The present invention relates to a drill bit and a single pass drilling apparatus. The one-piece drill bit has a connection portion, adapted to be rigidly connected to a drill steel, a pilot part and a reamer part. The pilot part has first rock machining means. The reamer part has a first center line and second rock machining means. The second rock machining means is provided axially between said connection portion and said first rock machining means and to one side of the pilot part. The drill bit has a rotational direction. A side of the pilot part facing away from the reamer part is provided with a wear resistant means. The wear resistant means is integral with the first rock machining means.

1 . A one-piece drill designed for single-pass anchor bolting, said drill bit having a connection portion, adapted to be rigidly connected to a drill steel, a pilot part and a reamer part, said pilot part having first rock machining means, said reamer part having a first center line and second rock machining means, said second rock machining means being provided axially between said connection portion and said first rock machining means and to one side of the pilot part, said drill bit having a rotational direction, wherein a side of the pilot part facing away from the reamer part is provided with a wear resistant means, said wear resistant means being integral with the first rock machining means. 
   
   
       2 . The drill bit according to  claim 1 , wherein an imaginary line, extending through the first rock machining means and being perpendicular to the first center line of the reamer part, forms an acute first angle with a normal to the first center line and wherein the normal intersects a rock machining means that leads in the rotational direction of the drill bit. 
   
   
       3 . The drill bit according to  claim 2 , wherein the first angle is not less than 0° and not more than 20°. 
   
   
       4 . The drill bit according to  claim 2 , wherein the leading rock machining means in the reamer part is a button and wherein the normal intersects its center line. 
   
   
       5 . The drill bit according to  claim 2 , wherein the normal intersects the forward most point of the leading rock machining means in the rotational direction. 
   
   
       6 . The drill bit according to  claim 2 , wherein the first rock machining means is a chisel, and the second rock machining means is at least three button. 
   
   
       7 . The drill bit according to  claim 1 , wherein a middle line of the pilot part forms an acute second angle with an axis extending parallel to the first center line. 
   
   
       8 . The drill bit according to  claim 7 , wherein the second angle is −20° to +20°, excluding 0°. 
   
   
       9 . The drill bit according to  claim 1 , wherein the length of the pilot part is defined as a distance between the forward most portion of the pilot part and the forward most second rock machining means, in a direction parallel to the first center line, and wherein said length is at least 10 mm and not more than 60 mm. 
   
   
       10 . A single pass drilling apparatus comprising drilling means and an anchor bit wherein the apparatus comprises a one-piece drill bit as defined in  claim 1 . 
   
   
       11 . The drill bit according to  claim 3 , wherein the leading rock machining means in the reamer part is a button and wherein the normal intersects its center line. 
   
   
       12 . The drill bit according to  claim 3 , wherein the normal intersects the forward most point of the leading rock machining means in the rotational direction. 
   
   
       13 . The drill bit according to  claim 3 , wherein the first rock machining means is a chisel, and the second rock machining means is at least three button. 
   
   
       14 . The drill bit according to  claim 2 , wherein a middle line of the pilot part forms an acute second angle with an axis extending parallel to the first center line.