초록 ▼

A guidance system and method for increasing the accuracy of laser guided machines such as screeds, graders, earth movers, floor saws and floor finishing machines. The system includes a laser beam receiver for sensing a laser reference beam provided off the machine. The laser receiver signals an elec

A guidance system and method for increasing the accuracy of laser guided machines such as screeds, graders, earth movers, floor saws and floor finishing machines. The system includes a laser beam receiver for sensing a laser reference beam provided off the machine. The laser receiver signals an electrical circuit when the laser beam is sensed in both centered and off-center regions. The electrical circuit operates a controller such as a solenoid operated fluid valve which controls a power source such as a fluid cylinder to move a machine element in one direction, such as raising a concrete screed, when the beam is sensed in the centered region, and in the other direction, such as lowering the screed, when the beam is sensed off-center. The method includes controlling the power source to continuously cycle the machine element between centered and off-centered regions to reduce the dead band, i.e., nonactive tolerance range, of the system.

대표청구항 ▼

A guidance system for a laser guided screeding apparatus, said apparatus including a screed for spreading and/or smoothing loose or plastic material such as uncured concrete, and elevation means for raising and lowering said screed relative to a laser reference beam located externally of said appara

A guidance system for a laser guided screeding apparatus, said apparatus including a screed for spreading and/or smoothing loose or plastic material such as uncured concrete, and elevation means for raising and lowering said screed relative to a laser reference beam located externally of said apparatus, said system comprising: laser beam receiving means mounted on and movable with said screed for sensing the laser reference beam in a first, centered, on target region and in a second, off-center region of said receiving means; electrical circuit means connected electrically to said laser beam receiving means for providing a first electrical condition when said screed and said laser beam receiving means are in said first on target region and a second electrical condition when said screed and said laser beam receiving means are in said second region; said elevation means adapted to raise and lower said screed and laser beam receiving means between said first on target region and said second off-center region; and control means connected electrically to said electrical circuit means and mounted on said screed for continuously operating said elevation means to move said screed and laser beam receiving means between said first and second regions, said control means operating in response to said electrical circuit means to move said screed and laser beam receiving means from said first on target region to said second off-center region when said electrical circuit means provides said first condition, and for operating said elevation means to move said screed and said laser beam receiving means from said second off-center region back to said first on target region when said electrical circuit means provides said second condition, whereby the machine element will continuously cycle between said on target and off-center regions while reducing the dead band of said system.