Patents Assigned to NKG Spark Plug Co., Ltd.
  • Patent number: 7094720
    Abstract: A dielectric ceramic composition is provided which exhibits a high unloaded quality factor (Qu) and permits regulation of the relative dielectric constant (?r) and the temperature coefficient (?f) of resonance frequency (fo) within specific ranges in accordance with use or application of the composition. A dielectric resonator is also provided which includes a resonator main body formed from the composition. The dielectric ceramic composition contains, as metallic components, Ba, Zn, Nb, Ta, and Sb, and the amounts of the metallic components, as reduced to their oxides, satisfy the following relations expressed in mol %: 57.5?BaO?62.6; 16.0?ZnO?22.2; 0<Nb2O5?20.6; 0<Ta2O5?20.6; and 0<Sb2O3?5.9.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: August 22, 2006
    Assignee: NKG Spark Plug Co., Ltd.
    Inventors: Takashi Oba, Hisashi Koduka, Kazuhisa Itakura
  • Patent number: 6831530
    Abstract: A monolithic LC filter which provides increased magnetic field coupling as compared with a conventional monolithic LC filter, without an increase in component size of the filter. The monolithic LC filter includes first and second resonator inductors coupled together by magnetic field coupling. The inductors include parallel-extending straight coupling sections formed by conductive lines which extend in parallel generally along a diagonal of a supporting dielectric layer. This configuration enables the lengths of the coupling sections to be increased as compared with the lengths of the corresponding coupling sections of a conventional monolithic LC filter.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: December 14, 2004
    Assignee: NKG Spark Plug Co., Ltd.
    Inventors: Junichi Ichikawa, Tadashi Shingaki, Norihisa Kitajima
  • Patent number: 5122768
    Abstract: An improved stripline filter is disclosed which includes a laminate of a pair of dielectric substrates each having an outer surface provided with a ground conductor, and conducting resonator means provided between each of the two adjacent dielectric substrates and having a plurality of parallel resonator fingers each having an open circuit end and a base end electrically connected to said ground conductor, in which the ground conductor has extended portions corresponding in number to the number of the resonator fingers, each of the extended portions extending toward the open circuit end of the corresponding resonator finger and terminating with a predetermined space from the open circuit end of the corresponding resonator finger.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: June 16, 1992
    Assignee: NKG Spark Plug Co., Ltd.
    Inventors: Kenji Ito, Naomasa Wakita
  • Patent number: 5003131
    Abstract: A device for connecting a metal conductor on a surface of a first ceramic body to an outer terminal in which dispersion of copper metal into adjoining layers is prevented. An outer surface conductor made of Cu or Au is connected to the metal conductor on the surface of the ceramic body and extends through a throughhole in a second ceramic body. A lower conductive layer of Pd is formed over and in electrical connection with the outer end of the outer surface conductor, the lower layer having an area greater than the area of the outer end of the outer surface conductor. A dispersion-preventing layer is formed on a portion of the lower layer concentric with the outer end of the outer surface conductor, the dispersion-preventing layer having an area greater than the area of the outer end of the outer surface conductor but less than the area of the lower layer. The dispersion-preventing layer is made of a crystallized glass material.
    Type: Grant
    Filed: September 8, 1989
    Date of Patent: March 26, 1991
    Assignee: NKG Spark Plug Co., Ltd.
    Inventors: Asao Morikawa, Kazuo Kondo
  • Patent number: 4785720
    Abstract: A piston boss is formed with an oil inlet hole for collecting oil flowing downward along a piston and allowing it to flow toward a snap ring and an end of a ceramic piston pin in contact with the snap ring. The oil having lubricated the snap ring and the end of the piston pin is collected by an oil outlet hole formed in the piston boss and allowed to flow downward therethrough.
    Type: Grant
    Filed: June 11, 1987
    Date of Patent: November 22, 1988
    Assignee: NKG Spark Plug Co., Ltd.
    Inventors: Takio Kojima, Mitsuyoshi Kawamura, Shigeaki Akao
  • Patent number: 4777155
    Abstract: The disclosure relates to a sintered aluminum nitride base composite material which consists essentially of 5-50 wt % of SiC whiskers, 0.5-10 wt % of sintering assistant(s) selected from SiO.sub.2, Y.sub.2 O.sub.3, CaO, Al.sub.2 O.sub.3, Mo, W, Mo.sub.2 C, WC and oxides of elements of the lanthanide series and the balance of AlN. By virtue of dispersion of SiC whiskers in AlN base ceramic matrix the sintered material is very enhanced in strength, toughness and hardness and exhibits increased heat conductivity. The sintered material provides excellent cutting tools since Rockwell superficial hardness, 45N scale, can be made higher than 85.
    Type: Grant
    Filed: September 12, 1986
    Date of Patent: October 11, 1988
    Assignee: NKG Spark Plug Co., Ltd.
    Inventors: Hidetoshi Baba, Hisashi Ito