Percussive rock drill bit

Abstract

A percussive rock drill bit includes a head provided at one end of a rearwardly projecting skirt. The head has an outer collar that defines, in part, a rearwardly projecting recess formed in the forwardmost region of the head. Peripheral gauge buttons are provided at the collar to surround side and front facing buttons formed at the head recess. The drill bit is effective to provide stabilised cutting to minimise lateral deflection.

1 . A percussive rock drill bit comprising:
 a head coupled to a rearwardly projecting skirt, a longitudinal axis extending through the head and the skirt, the head having a front face and an outer collar being raised and projecting axially forward of the front face, the collar having an inner sloping surface inclined relative to the axis and being radially inward facing such that the front face and the sloping surface define a rearwardly projecting cavity in a forward region of the bit;   a plurality of gauge buttons distributed over the collar and mounted at the head to tilt radially outward from the axis;   a plurality of front buttons distributed over the front face; and   a plurality of side buttons distributed over the inner sloping surface of the collar wherein at least a portion of each gauge button is positioned axially forwardmost of each side button.   
     
     
         2 . The drill bit as claimed in  claim 1 , wherein each side button is mounted at the head to tilt radially inward towards the axis. 
     
     
         3 . The drill bit as claimed in  claim 1 , wherein a diameter of the gauge buttons is greater than a diameter of the side buttons. 
     
     
         4 . The drill bit as claimed in  claim 1 , a diameter of the gauge buttons is greater than a diameter of the front buttons. 
     
     
         5 . The drill bit as claimed in  claim 1 , wherein the gauge buttons are tilted radially outward from the axis at an angle in the range of 30 to 45°. 
     
     
         6 . The drill bit as claimed in  claim 1 , wherein the side buttons are tilted radially towards from the axis at an angle in the range of 30 to 45°. 
     
     
         7 . The drill bit as claimed in  claim 5 , wherein the gauge buttons and the side buttons are tilted at an angle of substantially 40°. 
     
     
         8 . The drill bit as claimed in  claim 1 , wherein the collar includes a peripheral surface extending around the inner sloping surface and orientated to be declined relative to the axis to be radially outward facing, the gauge buttons projecting from the peripheral surface. 
     
     
         9 . The drill bit as claimed in  claim 1 , wherein the gauge, front and side buttons are selected from the group of a domed shape configuration, a rounded shape configuration, a conical shape configuration, a ballistic shape configuration a semi-spherical shape configuration, a flat end configuration and a combination thereof. 
     
     
         10 . The drill bit as claimed in  claim 1 , comprising eight gauge buttons. 
     
     
         11 . The drill bit as claimed in  claim 1 , comprising six side buttons. 
     
     
         12 . The drill bit as claimed in  claim 1 , comprising four front buttons. 
     
     
         13 . The drill bit as claimed in  claim 1 , wherein the collar includes at least one groove extending axially between an end peripheral surface and the front face. 
     
     
         14 . The drill bit as claimed in  claim 1 , wherein the collar includes at least one channel extending from an end peripheral surface axially towards the front face.