Patents by Inventor Tsutomu Yokoi

Tsutomu Yokoi 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: 5197804
    Abstract: A resistance film of platinum is formed on an insulating substrate of alumina. The resistance film is divided by grooves passing therethrough to provide a zigzag resistance circuit pattern, and the film forms a pair of terminal electrodes electrically connected to end portions of the resistance circuit pattern, respectively. In order to stop transmission of heat generated in the resistance circuit pattern to the terminal electrodes, gaps for stopping heat conduction are formed between the resistance circuit pattern and each of the terminal electrodes.
    Type: Grant
    Filed: November 16, 1990
    Date of Patent: March 30, 1993
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroji Tani, Tsutomu Yokoi, Tohru Kasanami
  • Patent number: 4994782
    Abstract: A variable resistor comprising a substrate provided on the surface thereof with a resistor on which a sliding member is in slidable contact therewith. The substrate is formed of diallyl phthalic resin, and a carbon resistor formed with a predetermined shape is molded integrally on the surface of the resin substrate. The carbon resistor contains diallyl phthalic resin as a binder resin. Terminals and the carbon resistor molded on the resin substrate are electrically connected through conductive paste. A variable resistor with good physical characteristics is obtained that can be manufactured at low cost, with superior heat resistance, capable of mounting by flow soldering, and having a small rate of resistance value. In addition, since the resistor and the terminals are connected through the conductive paste, connecting strength thereof is not only brought about by physical pressure but reinforced by the adhesion of the conductive paste.
    Type: Grant
    Filed: August 25, 1989
    Date of Patent: February 19, 1991
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroyuki Watanabe, Hiroji Tani, Tsutomu Yokoi
  • Patent number: 4877565
    Abstract: A method of manufacturing a stator for a variable resistor comprises a step of preparing a heat resistant film, a step of providing a resistor film on the heat resistant film, a step of obtaining a transfer sheet by treating the resistor film provided on the heat resistant film with a silane coupling agent, a step of preparing a forming die having a cavity for forming a substrate, a step of locating the transfer sheet in the forming die to expose at least a part of the resistor film in the cavity, a step of introducing resin into the cavity to form a substrate joined with at least a part of the resistor film and a step of separating the heat resistant film from the substrate to leave the resistor film.
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: October 31, 1989
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Hiroji Tani, Tohru Kasanami, Tsutomu Yokoi
  • Patent number: 4877554
    Abstract: Resistance paste comprises conductive powder suspended in a binder resin, and is characterized in that the conductive powder comprises graphite powder of which particles are coated or covered with at least one higher fatty acid having at least 12 carbon atoms. The paste may contain carbon black as a part of the conductive powder. The paste may further contain a filler, preferably, fine powder of talc having a mean particle diameter of not more than 5 .mu.m.
    Type: Grant
    Filed: July 21, 1988
    Date of Patent: October 31, 1989
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Kanehito Honma, Tsutomu Yokoi, Hiroji Tani
  • Patent number: 4839960
    Abstract: A stator for a variable resistor, manufactured by a step of preparing a heat resistant film of polyimide, a step of preparing a transfer sheet by providing a resistor film containing carbon powder and allyle resin, such as diallyl phthalate resin, on the heat resistant film, a step of preparing a lead terminal, a step of preparing a forming die having a cavity for forming a substrate, a step of locating the transfer sheet and the lead terminal in the forming die to expose at least a part of the resistor film in the cavity and position a part of the lead terminal in the cavity, a step of introducing allyle resin, such as diallyl phthalate resin, into the cavity to form a substrate joined with at least a part of the resistor film, in which substrate a part of the lead terminal is buried, and a step of separating the heat resistant film from the substrate to leave the resistor film.
    Type: Grant
    Filed: May 25, 1988
    Date of Patent: June 20, 1989
    Assignee: Murata Manufacturing Co.,Ltd.
    Inventors: Tsutomu Yokoi, Hiroji Tani, Tohru Kasanami, Norio Fukui, Keizou Yamamoto
  • Patent number: 4547310
    Abstract: A carbon resistive paste comprising an electrically conductive component, such as carbon; an inorganic filler, such as silica; a resin component, such as an epoxy resin; a solvent, such as ethanol and; if necessary, an organic filler, wherein the inorganic filler is treated with a silane coupling agent, such as .gamma.-glycidoxypropyltrimethoxy silane. The carbon resistive paste provides a resistive film which has limited changes in resistance value in use and is superior in strength.
    Type: Grant
    Filed: March 23, 1984
    Date of Patent: October 15, 1985
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tohru Kasanami, Hirozi Tani, Tsutomu Yokoi