Patents Assigned to Kokoku Rubber Industrial Company Limited
  • Patent number: 4571466
    Abstract: A spring unit for a keyboard comprises a base sheet having a specified number of openings perforated thereupon in accordance with a key layout and a number of dome-shaped spring members separated individually from each other, and each bearing a movable contact point for completing a circuit between fixed contact points. Each of the spring members is removably engaged with an opening in the base sheet. The spring members are molded from a high polymer resilient material and are easily replaceable.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: February 18, 1986
    Assignee: Kokoku Rubber Industrial Company Limited
    Inventor: Hideo Iida
  • Patent number: 4533604
    Abstract: This invention relates to a pressure-sensitive and conductive rubber, wherein an involatile or volatile liquid organic substance is impregnated with and swelled in a composite conductive rubber obtained by adding a conductive filler such as a carbon black, metallic fine powders or the like thereto, the involatile or volatile liquid organic substance having compatibility with the composite conductive rubber. The involatile or volatile organic substance immersed in the composite conductive rubber is penetrated between adjacent particles of the conductive filler, thereby respective distances between the adjacent particles thereof are widened and a conductivity resistance of energizing route in the composite conductive rubber under a normal condition is increased.
    Type: Grant
    Filed: June 10, 1983
    Date of Patent: August 6, 1985
    Assignee: Kokoku Rubber Industrial Company Limited
    Inventors: Kazuhiro Honda, Hiroshi Kuramochi
  • Patent number: 4529539
    Abstract: This invention relates to an electrically conductive high-molecular composition which is obtained by mixing a preferred base high-molecular compound such as a thermoplastic resin, a synthetic resin, a rubber or the like with a water-soluble electrolyte and a water-soluble high-molecular compound at a certain desired compounding ratio. More particularly, the water-soluble electrolyte is ionized within an article molded by the base high-molecular compound due to a water content in atmosphere, thereby the water-soluble high molecular compound phase is transferred and the antistatic action is obtained accordingly. The conductive high-molecular composition can be transparent and colored to any desirable color. The compounding ratio of the water-soluble electrolyte and the water-soluble high-molecular compound respectively per 100 weight parts of the base high-molecular compound is from 1 to 10 weight parts.
    Type: Grant
    Filed: May 9, 1983
    Date of Patent: July 16, 1985
    Assignee: Kokoku Rubber Industrial Company Limited
    Inventors: Masayuki Monma, Hiroshi Kuramochi
  • Patent number: 4386175
    Abstract: This invention relates to a resin composition characterized in that a conventional chemical etching treatment is removed and instead of it a surface of the resin composition is plated with a metallic layer having a strong adhesive force, by means of a surface treatment by only a dry etching. Accordingly, the surface thereof can be directly treated with electroplating. Further, the use of chromic acid as a source of environmental pollution or other conventional addition agents for the surface treatment is completely eliminated.
    Type: Grant
    Filed: February 1, 1980
    Date of Patent: May 31, 1983
    Assignee: Kokoku Rubber Industrial Company Limited
    Inventors: Hiroshi Kuramochi, Noriaki Nakajo, Makoto Abekura, Jun Matsumoto
  • Patent number: 4372740
    Abstract: This invention relates to a molding apparatus capable of producing flashless molded parts due to a perfect surface-to-surface mating of a pair of molds. The molding apparatus comprises an upper holding means for holding at least one upper mold having a path in which a moldable material is passable, and a lower holding means for holding at least one lower mold having a cavity, wherein a certain amount of fluid substance is filled between a bottom surface of the lower mold and the lower holding means, thereby the lower mold being floatable on the fluid substance and movable along the lower holding means, subsequently a joint between the upper mold bottom surface and the lower mold top surface being realized perfectly due to a back pressure of the fluid substance.
    Type: Grant
    Filed: February 20, 1981
    Date of Patent: February 8, 1983
    Assignee: Kokoku Rubber Industrial Company Limited
    Inventors: Hiroshi Kuramochi, Ryuichi Toyoda