Laser beam control system for earthworking or similar machines

Apparatus for controlling the working height of a portion of earthworking tool carried by a mobile vehicle and vertically adjustable relative thereto by power means comprising:

• 1. a flexible tape having two sets of indicia thereon equally spaced along the tape, one set of indicia corresponding to desired changes in elevation of said earthworking tool portion at predetermined points along the planned path of travel of the vehicle, the other set of indicia indicating the distance between said points;
• 2. a feeding mechanism for said tape mounted on said vehicle and constructed and arranged to intermittently move said tape past a reading station by a distance equal to the longitudinal spacing of said indicia;
• 3. means responsive to movement of said vehicle for actuating said feeding mechanism each time the vehicle reaches the next one of said points;
• 4. electronic means for reading said indicia at said tape reading station, and
• 5. means for controlling said power means in response to the reading of one set of indicia, thereby adjusting the working height of said earthworking tool portion as the vehicle moves to each said point.

Apparatus for continuously controlling the vertical height and tilt of a vertically adjustable working tool of a mobile earthworking machine, said apparatus comprising, in combination:

• means for sensing the elevation of a laser beam periodically moving over the working area in a predetermined substantially horizontal plane;
• a first control means responsive to said laser beam for maintaining a predetermined vertical relationship between said plane and the vertical height of one end of said tool;
• a second control means responsive to said laser beam for maintaining a predetermined vertical relationship between said plane and the vertical height of the other end of said tool;
• and
• adjustment means for changing said predetermined relationships at predetermined points along the intended path of travel of said machine, said adjustment means comprising:
• 1. means on the machine for intermittently advancing an indicia-bearing tape past a reader station, said tape having three sets of equally-spaced indicia thereon, two sets respectively indicating each desired change in height of said ends of said tool at successive points along the path of travel of said machine, and the third set of indicia indicating the distance to be travelled by the machine until the next change in tool elevation or tilt is desired,
• 2. means responsive to the movement of said machine for advancing said tape past the reader station by an increment corresponding to the spacing of said indicia whenever the machine reaches the next point where a change in height or tilt of said tool portion is required, and
• 3. reader means at said reader station respectively responsive to said two sets of indicia and operatively associated with said first and second control means for respectively changing said predetermined relationships to thereby effect the desired changes in height and tilt of said tool at said points.