Abstract: Methods for engraving carpet with beams of radiant energy. A beam of radiant energy, such as a laser beam, is intermittently directed at the surface of carpet to engrave the surface, and, if desired, to cause certain color changes. During the intermittent operation of the beam, the carpet is indexed to allow the beam to engrave designs. Alternatively, the beam may be indexed in relation to stationary carpet by means of lenses or mirrors to engrave designs. The method allows inexpensive and accurate engraving of carpet surfaces by which intricate designs may be formed on those surfaces in a minimum amount of time.

Abstract: An improved carpet tile for commercial, industrial or home use. The carpet tile has two straight first and second edges. Its third and fourth edges each have a portion removed to form key sections at the ends and a channel indentation in the middle. The tile when installed registers diagonally with like tiles because key sections from two tiles having adjacent straight edges are received by a channel indentation of each side edge of the tile. Movement of the tile in relation to other tiles is reduced and unsightly continuous edge lines across the carpet surface are eliminated. This invention is particularly useful when applied to free-lay carpet tiles, which use no adhesive to hold them to the underlying surface, because it prevents such tiles from delaminating, curling or warping. The simple shape of the tile allows it to be manufactured and installed quickly and inexpensively.