Attack tool assembly

Abstract

An attack tool assembly ( 10 ) comprising an attack tool having a shank ( 23 ) extending therefrom, the shank ( 23 ) having a longitudinal axis; and a holder having a holder body ( 31 ) and a bore for receiving the shank ( 23 ) of the attack tool ( 10 ); the holder being adapted to receive the shank ( 23 ) in a configuration in which it prevents the shank ( 23 ) from rotating relative to the bore when the holder is in an engaged condition, and in which it allows the shank ( 23 ) to be rotatable relative to the bore when the holder is in a disengaged condition, so as to enable the shank ( 23 ) to be selectively securable to the holder in a required orientation about the longitudinal axis. The attack tool assembly ( 10 ) is particularly but not exclusively for use in the degradation of rock or asphalt bodies for formations, such as in soft rock mining and asphalt milling.

1 . An attack tool assembly comprising an attack tool having a shank extending therefrom, the shank having a longitudinal axis; and a holder having a bore for receiving the shank of the attack tool; the holder being adapted to receive the shank in a configuration in which it prevents the shank from rotating relative to the bore when the holder is in an engaged condition, and in which it allows the shank to be rotatable relative to the bore when the holder is in a disengaged condition, so as to enable the shank to be selectively securable to the holder in a required orientation about the longitudinal axis. 
     
     
         2 . The attack tool assembly according to  claim 1 , in which the holder includes engagement means for securing the shank relative to the holder, the engagement means engaging the shank when the holder is in an engaged condition, and being spaced apart from the shank when the holder is in a disengaged condition. 
     
     
         3 . The attack tool assembly according to  claim 1 , in which the bore engages the shank when the attack tool assembly is in the engaged condition, and wherein the disengaged condition is achievable by heating the holder. 
     
     
         4 . The attack tool assembly as claimed in  claim 1 , in which at least part of the shank is cylindrical or frustoconical in shape. 
     
     
         5 . The attack tool assembly as claimed in  claim 1 , in which the attack tool comprises a superhard tip joined to a cemented carbide support body. 
     
     
         6 . The attack tool assembly as claimed in  claim 1 , in which the attack tool comprises a polycrystalline diamond structure bonded to a cemented carbide substrate. 
     
     
         7 . The attack tool assembly as claimed in  claim 1 , in which the engagement means is in the form of a protrusion that protrudes into the bore, the protrusion being displaceable between an engaged position in which an end of the protrusion abuts the shank, and a retracted position, in which the end of the protrusion is spaced apart from the shank. 
     
     
         8 . The attack tool assembly according to  claim 7  wherein the protrusion is in the form of a threaded rod extending through a threaded aperture provided in the holder. 
     
     
         9 . The attack tool assembly according to  claim 1 , in which the shank includes an engagement zone that is not cylindrically rotationally symmetric, the engagement zone in use being at least partially aligned with the threaded aperture in the holder. 
     
     
         10 . The attack tool assembly according to  claim 9 , in which the engagement zone includes a plurality of substantially planar surfaces located about a periphery of the shank, in order for the protrusion in use to abut a selected planar surface when in the engaged position. 
     
     
         11 . The attack tool assembly as claimed in  claim 1 , comprising an attack tool and a holder configured such that the attack tool is continuously indexable within the holder. 
     
     
         12 . A method of releasing an attack tool from a steel holder of an attack tool assembly the method including the step of heating the steel holder to expand the bore. 
     
     
         13 . A method of using an attack tool assembly as claimed in  claim 1 , the method including using the attack tool assembly to degrade a body, putting the holder into the disengaged condition to release the attack tool, reorienting the attack tool within the holder; putting the holder into the engaged condition; and further using the attack tool assembly to degrade a body.