Patents by Inventor Tadashi Koseki

Tadashi Koseki 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).

  • Large-heat-input butt welded joints having excellent brittle fracture resistance
    Patent number: 7829202
    Abstract: A large-heat-input butt-welded joint of welded structures prepared by butt-welding high-strength steel plates over 50 mm in thickness, having excellent brittle fracture resistance, is characterized by: (a1) the hardness of the weld metal is not more than 110% of the hardness of the base metal or (a2) the hardness of the weld metal is not less than 70% and not more than 110% of the hardness of the base metal, and, as required, (b) the width of the weld metal is not more than 70% of the plate thickness of the base metal, (c) the width of the region affected by welding whose hardness is softened to not more than 95% of the hardness of the non-heat-affected base metal has a width not less than 5 mm, and/or (d) the prior austenite grain size in the heat-affected zone (HAZ) contacting the welding fusion line is not more than 200 ?m.
    Type: Grant
    Filed: October 22, 2004
    Date of Patent: November 9, 2010
    Assignee: Nippon Steel Corporation
    Inventors: Tadashi Ishikawa, Takehiro Inoue, Hiroshi Shimanuki, Tadashi Koseki, Jun Otani, Masanori Minagawa, Akihiko Kojima
  • Welded structure having excellent resistance to brittle crack propagation and welding method therefor
    Patent number: 7748596
    Abstract: A welding method for manufacturing welded structures having excellent properties to prevent the propagation of brittle fracture occurring in welded joints, characterized by the step of forming a repair weld having a greater toughness than that of a butt weld and an outer edge whose angle ? with respect to the longitudinal direction of the butt weld is not less than 10 degrees and not more than 60 degrees, by applying repair welding to a region to arrest a brittle crack in a butt-welded joint where a brittle crack is likely to propagate after removing part of the butt-welded joint, in said region, by gouging or machining.
    Type: Grant
    Filed: July 13, 2006
    Date of Patent: July 6, 2010
    Assignee: Nippon Steel Corporation
    Inventors: Tadashi Ishikawa, Takehiro Inoue, Hiroshi Shimanuki, Tadashi Koseki
  • Large-heat-input butt welded joints having excellent brittle fracture resistance
    Publication number: 20070131316
    Abstract: A large-heat-input butt-welded joint of welded structures prepared by butt-welding high-strength steel plates over 50 mm in thickness, having excellent brittle fracture resistance, is characterized by: (a1) the hardness of the weld metal is not more than 110% of the hardness of the base metal or (a2) the hardness of the weld metal is not less than 70% and not more than 110% of the hardness of the base metal, and, as required, (b) the width of the weld metal is not more than 70% of the plate thickness of the base metal, (c) the width of the region affected by welding whose hardness is softened to not more than 95% of the hardness of the non-heat-affected base metal has a width not less than 5 mm, and/or (d) the prior austenite grain size in the heat-affected zone (HAZ) contacting the welding fusion line is not more than 200 ?m.
    Type: Application
    Filed: October 22, 2004
    Publication date: June 14, 2007
    Inventors: Tadashi Ishikawa, Takehiro Inoue, Hiroshi Shimanuki, Tadashi Koseki, Jun Otani, Masanori Minagawa, Akihiko Kojima
  • Welded structure having excellent resistance to brittle crack propagation and welding method therefor
    Publication number: 20070040001
    Abstract: A welding method for manufacturing welded structures having excellent properties to prevent the propagation of brittle fracture occurring in welded joints, characterized by the step of forming a repair weld having a greater toughness than that of a butt weld and an outer edge whose angle ? with respect to the longitudinal direction of the butt weld is not less than 10 degrees and not more than 60 degrees, by applying repair welding to a region to arrest a brittle crack in a butt-welded joint where a brittle crack is likely to propagate after removing part of the butt-welded joint, in said region, by gouging or machining.
    Type: Application
    Filed: July 13, 2006
    Publication date: February 22, 2007
    Inventors: Tadashi Ishikawa, Takehiro Inoue, Hiroshi Shimanuki, Tadashi Koseki
  • Weld structure having excellent resistance brittle crack propagation resistance and method of welding the weld structure
    Publication number: 20070000968
    Abstract: A welding method for manufacturing welded structures having excellent properties to prevent the propagation of brittle fracture occurring in welded joints, characterized by the step of forming a repair weld having a greater toughness than that of a butt weld and an outer edge whose angle ? with respect to the longitudinal direction of the butt weld is not less than 10 degrees and not more than 60 degrees, by applying repair welding to a region to arrest a brittle crack in a butt-welded joint where a brittle crack is likely to propagate after removing part of the butt-welded joint, in said region, by gouging or machining.
    Type: Application
    Filed: October 7, 2004
    Publication date: January 4, 2007
    Inventors: Tadashi Ishikawa, Takehiro Inoue, Hiroshi Shimanuki, Tadashi Koseki
  • Wheel loader
    Patent number: D693853
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: November 19, 2013
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Kazuhiko Hiraoka, Kouji Kimijima, Akira Shimohira, Hiroaki Yada, Kouji Takehi, Katsuhisa Onoguchi, Seiji Nakagawa, Yuuji Akutsu, Tadashi Koseki, Wataru Isaka, Hirofumi Oouchi