| 摘要 |
<p>A tool-carrying vehicle is provided with an apparatus for maintaining a predetermined distance between its blade and a laser reference plane generated by a rotating laser beam. The apparatus includes a detector housing supported on a mounting extending upwardly from the blade, a detector support frame on the housing, a laser reference plane detector on the support frame, and electrical control circuitry. The mounting is movable to permit moving the detector housing relative to the vehicle in response to tool movement. The laser reference plane detector has first and second spaced apart laser beam detecting arrays, and is provided with upper and lower movable carriages with one of the arrays positioned on each carriage, permitting the carriages to converge and diverge to vary the distance separating the detecting arrays and thereby control the degree of accuracy required of the tool. In addition, the detector housing may be rotated about its axis to scan an arc for the laser beam. The elevation and slope of the blade or tool may be automatically controlled as a function of position or time by a computer carried by the vehicle and operating under a predetermined computer program to thereby accurately grade a given area.</p> |
