Patent ID: 8640878

Claim:
A grader comprising: a grading bed declining from an upstream infeed end to a lower downstream end and extending in width from a first side to a second side and providing a top grading surface and an opposite bottom surface; a support underlying the grading bed across a space between the support and the grading bed; biasing means for biasing the grading bed toward the support; a plurality of grading rollers extending across the width of the grading bed and spaced above the grading bed across gaps, wherein the grading rollers have axes of rotation oblique to the first and second sides; a plurality of jacks extending from the support and through the space between the support and the grading bed generally along lines parallel to and proximate the plurality of grading rollers and into contact with the bottom surface of the grading bed, wherein the jacks are height-adjustable to maintain the top grading surface flat proximate the grading rollers.