Patents by Inventor Keiji Wakamatsu

Keiji Wakamatsu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5216570
    Abstract: An arresting insulator is provided which includes an insulator body made of an insulative material and a non-linear resistor. The insulator body includes a head for linking the insulator to an adjacent insulator, and a shed formed integrally with the head. The resistor is secured in the insulator body and has a non-linear relation between residual voltage and current. More specifically, the resistor has a characteristic that satisfies the equation:V.sub.NmA /H.gtoreq.300 V/mmwherein V.sub.NmA is a threshold reference voltage that causes a current of at least N milliamps to start flowing across the resistor to cause the resistor to perform a surge absorbing function. N is an arbitrary value in the range of 1 to 10, and H is the axial length of the resistor along a direction of electric field in millimeters.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: June 1, 1993
    Assignees: Tokyo Electric Power Co., Inc., NGK Insulators, Ltd.
    Inventors: Tsuruo Yorozuya, Keiji Wakamatsu, Takashi Irie, Takashi Ohashi
  • Patent number: 4761707
    Abstract: A lightning-conducting insulator is disclosed, which comprises an insulator body consisting of a shed portion, a plurality of rib portions provided inside the shed portion, and a cup-like cylindrical head portion at a central upper portion of the shed portion, and a metal cap put and fixed onto the head portion, and a metal pin inserted and fixed inside the head portion. A cylindrical fitting section with a through hole is provided in the shed portion. At least one current-limiting element having a non-linear voltage-current characteristic is inserted into the through hole of the cylindrical fitting section. The cylindrical fitting section is sealed with a glass- and ceramics-bonding metal solder such that the upper and lower end faces of the current-limiting element and the end faces of the cylindrical fitting section may be continuously sealed.
    Type: Grant
    Filed: July 10, 1987
    Date of Patent: August 2, 1988
    Assignees: The Tokyo Electric Co., Inc., NGK Insulators, Ltd.
    Inventors: Keiji Wakamatsu, Tetsuya Nakayama, Jun Atsumi