Patents Assigned to Limited and Kajima Corporation
  • Carbon fiber-reinforced cement material and method for preparing same
    Patent number: 5308696
    Abstract: A method for preparing a carbon fiber-reinforced cement material is here disclosed which comprises the step of using, as a reinforcing material, a carbon fiber from which a gas has been removed by replacing the gas captured in the fiber with water. This method permits providing the carbon fiber-reinforced cement material having a large reinforcing effect by the fiber.
    Type: Grant
    Filed: June 29, 1992
    Date of Patent: May 3, 1994
    Assignees: Mitsui Mining Company, Limited and Kajima Corporation
    Inventors: Kazuhiko Hanashita, Koji Sakata, Shigeru Kanamaru, Toshiyuki Nawa, Kozo Toyama, Yoshikazu Takei, Tatsuo Suenaga, Yoshikazu Taniguchi
  • Laser beam-detonatable blasting cap
    Patent number: 4898095
    Abstract: A laser beam-detonatable blasting cap containing secondary explosives charged therein in the upper and lower portions, wherein the explosive charged in the upper portion contains a laser beam-absorbing black material and is contacted with an optical fiber at the top. The loading density of the explosive charged in the lower portion is higher than that of the explosive charged in the higher portion, and only the side of the explosive charged in the upper portion is surrounded with a restraining wall. The blasting cap can be easily and surely detonated by a laser beam having a low peak output power generated by means of a pulse-oscillation system without using Q-switching or a continous oscillation system.
    Type: Grant
    Filed: April 13, 1988
    Date of Patent: February 6, 1990
    Assignees: Nippon Oil and Fats Company, Limited and Kajima Corporation, Kajima Corporation
    Inventors: Yoji Tasaki, Koichi Kurokawa, Katsuhide Hattori, Mikio Takano, Toshikazu Miyajima, Toshifumi Sato, Katsura Ogasawara