Patents Examined by Wright Alan
  • Spark plug insulator and a method of sintering
    Patent number: 5283134
    Abstract: A spark plug insulator is desirably made up of a sintered body of AlN-based ceramic powder comprising about 60-98% AlN and a sintering additive. There is provided on the surface of the sintered body a layer of pyrolytic boron nitride having a thickness in the range 10-100 .mu.m.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: February 1, 1994
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Makoto Sugimoto, Hiroyuki Tanabe, Mamoru Musasa