Towable box grader with electronically controlled continuously variable multi-axis blade system

A towable scraper system for contour surface grading, comprising:

• a control system;
• a rigid chassis member having a three-point coupler configured for attachment to a three-point tractor hitch;
• a bi-directional box-scraper blade pivotally suspended from said rigid chassis member on a first axis aligned with a towing direction;
• a blade motivator for causing an angular rotation of said blade around said first axis;
• a lift assembly for raising and lowering said rigid chassis member to control a height of said blade relative to a work surface to be graded, said blade motivator and said lift assembly responsive to said control system for continuously controlling said angular rotation and said height of said bi-directional box scraper blade for automatically grading a work surface to a predetermined contour;
• a carriage assembly for providing a rolling support for said rigid chassis over said work surface, said carriage assembly comprising a carriage frame with at least one wheel frame pivotally mounted thereto, and a wheel rotatably mounted to said wheel frame, said carriage frame pivotally coupled to said rigid chassis on a second axis aligned with said towing direction and at a location opposed to said coupler, said carriage frame configured for angular rotation around a said second axis;
• and
• wherein said lift assembly is comprised of a lift frame pivotally connected on a proximal end to said rigid chassis member opposed from said coupler, and rigidly attached on a distal end to said carriage assembly.

A towable scraper system for contour surface grading, comprising:

• a rigid chassis member having a coupler configured for attachment to a three point tractor hitch;
• a scraper blade pivotally suspended from said rigid chassis member and a blade motivator for causing an angular rotation of said blade around an axis aligned with a towing direction;
• a lift assembly for raising and lowering said rigid chassis member to control a height of said blade relative to a work surface to be graded;
• a carriage assembly for providing a rolling support for said rigid chassis over said work surface, said carriage assembly pivotally coupled to said rigid chassis at a location opposed to said coupler, said carriage assembly configured for angular rotation around a second axis aligned with said towing direction;
• and
• wherein said blade motivator is comprised of a rigid support arm extending above said rigid chassis member and a hydraulic cylinder attached between an upper portion of said rigid support arm and said scraper blade.