Grader blade extension

Abstract

An extension for a grader blade which is used to dig a concave ditch includes a body for mounting on or integral with one end of the grader blade, the body having a convex outer side edge adapted to scoop out a curved-bottom ditch when the grader blade is angled from the horizontal with the extension at the lowermost end of the blade, and moved through the surface.

1 . An extension for a grader blade having a pair of ends and a bottom edge comprising a body on one blade end, the body having an inner side edge conforming to the one blade end and an outer side edge adapted to form a curved-bottom ditch in a surface when said grader blade is angled from the horizontal with the extension at a lowermost end of the grader blade and moved through the surface. 
   
   
       2 . The extension of  claim 1 , wherein the body is integral with the grader blade. 
   
   
       3 . The extension of  claim 2 , wherein said body is cup-shaped 
   
   
       4 . The extension of  claim 1 , wherein said body extends upwardly beyond a top edge of said grader blade. 
   
   
       5 . The extension of  claim 1 , wherein the grader blade includes a moldboard on a lower end thereof, and the extension includes an arcuate blade connected to a second end of said body and a cutting edge on said arcuate blade for forming the ditch. 
   
   
       6 . The extension of  claim 5 , wherein said arcuate blade has a cross section matching the cross section of the moldboard. 
   
   
       7 . The extension of  claim 5 , wherein said arcuate blade is concave. 
   
   
       8 . The extension of  claim 7 , wherein said arcuate blade has a straight inner end and is increasingly concave from said straight inner end to an outer, free end. 
   
   
       9 . The extension of  claim 7 , wherein said arcuate blade is more concave at its inner end than at the outer end thereof. 
   
   
       10 . The extension of  claim 1 , wherein said outer side edge is convex. 
   
   
       11 . The extension of  claim 10 , wherein said outer side edge defines a constant radius convex arc. 
   
   
       12 . The extension of  claim 10 , wherein said outer side edge defines a portion of an oval.