Laser-controlled ground leveling device with overfill sensor and wheel rise limiting device

Claim 1

In an earth leveling laser beam control system comprising earth scraping and storing means controllably displaceable over rough terrain for leveling said terrain, level defining laser beam transmitting means, laser beam receiving means mounted on said earth scraping and storing means, indicating means associated with said laser beam receiving means for indicating alignment of said earth scraping and storing means with said laser beam, and control means for lowering and raising said earth scraping and storing means for leveling said rough terrain to a pre-determined grade level as defined by said laser beam, the improvement comprising overfill sensor means in said scraping and storing means for detecting an excess of scraped earth in said scraping and storing means, means actuated by said overfill sensor means for dumping earth from said scraping and storing means upon receiving an appropriate signal from said overfill sensor means for preventing overfilling of said scraping and storing means, means actuated by said indicating means for preventing said control means from lowering said earth scraping and storing means while said indicating means is on, ground engaging wheels, pivotable support means interconnecting said ground supported wheels and said earth scraping and storing means, and control means mounted on said pivotable support means for maintaining said pivotal support means below a pre-determined angle for limiting the rise of said ground engaging wheels above the ground.