ALEXANDRIA, Va., June 4 -- United States Patent no. 12,319,842, issued on June 3, was assigned to DISCO Corp. (Tokyo).
"Production process of polishing stone and polishing stone" was invented by Ryogo Maji (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A production process of a polishing stone includes a glass sphere feeding step of feeding glass spheres into a mold, and a firing step of heating the mold with the glass spheres filled therein at a temperature higher than a softening point and lower than a melting point of the glass spheres, thereby forming a glass block as the polishing stone. In the firing step, the heating is stopped with air bubbles still dispersed and remaining in interstices betwe...