ALEXANDRIA, Va., June 4 -- United States Patent no. 12,322,930, issued on June 3, was assigned to Niterra Co. Ltd. (Nagoya, Japan).
"Insulator and spark plug" was invented by Yutaka Yokoyama (Nagoya, Japan), Toshiki Kon (Nagoya, Japan) and Ippei Kato (Nagoya, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A spark plug (1) includes a tubular insulator (50). The insulator contains alumina as a primary component, and further contains a secondary component. The secondary component contains a silicon (Si) component, a magnesium (Mg) component, a barium (Ba) component, a calcium (Ca) component, and a rare earth component. The amounts (mass %) of these components as reduced to oxide and relative to the total ...