Excavating tool and method for excavating rock, minerals and the like

Abstract

The invention provides an apparatus for excavating rock, minerals and the like, which includes a hub 22 connected to a rotatable drive. Cutting elements such as picks 20 a are supported by tool holders connected to the hub. The picks 20 a project radially from the hub, and are arranged in oblique relationship to the axis of rotation of the hub. The drive means is preferably designed to impart an eccentric, superimposed percussive action on the hub 22. During use the hub 22 is positioned facing a rock surface and urged along the rock face in transverse relationship to the axis of rotation of the hub, thereby causing the picks 20 a to undercut an adjacent region of rock, and thereby excavating successivel layers of rock.

1 . A method of excavating rock which includes the steps of 
 positioning a cutting tool having a rotatable hub equipped with cutting elements projecting radially from the hub, adjacent to the rock with the hub facing a clear surface of the rock; and    urging the rotating hub along a path in transverse relationship to its axis of rotation, thereby causing the cutting elements to undercut adjacent portions of the rock.    
     
     
         2 . A method of excavating rock according to  claim 1  which includes the further step of sequentially undercutting the rock by urging a further, similar rotating cutting tool having a hub with a larger diameter than that of the first, along substantially the same path as that followed by the first cutting tool.  
     
     
         3 . A method of excavating rock according to  claim 1  which includes the further step of simultaneously undercutting the rock by means of a further, substantially identical rotating cutting tool, with both tools operating in coplanar relationship and in vertical juxtaposition to each other.  
     
     
         4 . A method of excavating rock according to  claim 1  in which the cutting elements are directed in oblique relationship to the hub, towards the rock surface.  
     
     
         5 . A method according to  claim 1  in which the cutting elements are directed in oblique relationship to the rock surface by setting the orientation of the axis of rotation of the hub in oblique relationship to the rock face.  
     
     
         6 . An apparatus for excavating rock, which includes 
 a cutting tool having a hub connected to a rotatable drive; and    cutting elements connected to the hub, and projecting radially from the hub, the cutting elements being arranged in such a fashion that in use they obliquely undercut adjacent portions of rock when the hub is urged along a clear rock surface, in transverse relationship to the axis of rotation of the hub.    
     
     
         7 . An apparatus for excavating rock according to  claim 6  in which the rotatable drive is designed to impart a superimposed, eccentric percussive action on the hub during use.  
     
     
         8 . An apparatus for excavating rock according to  claim 6  or  claim 7 , which includes a further, similar cutting tool having a hub with a larger diameter than that of the first, the hubs being interlinked and arranged in substantially co-planar relationship to each other for sequentially undercutting the rock by causing the cutting tool with the larger hub to trail the path of the smaller cutting tool during use.  
     
     
         9 . An apparatus according to  claim 6  or  claim 7  which includes a further, substantially identical cutting tool, both cutting tools being interlinked and arranged in co-planar relationship and vertical juxtaposition to each other for simultaneously undercutting adjacent portions of rock.  
     
     
         10 . An apparatus for excavating rock according to any one of  claims 7  to  9  in which the hubs are interchangeable, and counterbalanced in relation to the drive means.  
     
     
         11 . An apparatus for excavating rock according to any one of  claims 6  to  10  in which the hub of each cutting tool has holders forming an integral part of the hub, for holding the cutting elements.  
     
     
         12 . An apparatus for excavating rock according to  claim 11  in which each hub is counterbalanced in relation to its associated drive means, and is interchangeable by way of a quick-release coupling.