Patents by Inventor Tadao Ishikawa
Tadao Ishikawa 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).
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Patent number: 8649198Abstract: Disclosed is a power conversion device which achieves reductions in switching loss due to a reverse recovery current and heat generation loss. Specifically disclosed is a power conversion device provided with a cascode element configured by electrically connecting a normally-on switching element and a normally-off switching element in series and connecting a gate terminal of the normally-on switching element and a source terminal of the normally-off switching element via a cascode connection diode, and a high-speed diode electrically connected in parallel with the cascode element and having a cathode region connected to a positive electrode terminal and an anode region connected to a negative electrode terminal.Type: GrantFiled: December 20, 2011Date of Patent: February 11, 2014Assignees: Kabushiki Kaisha Toshiba, Central Research Institute of Electric Power IndustryInventors: Atsuhiko Kuzumaki, Hiroshi Mochikawa, Takeru Murao, Masahiro Takasaki, Tadao Ishikawa, Toshiaki Kikuma
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Publication number: 20120087167Abstract: Disclosed is a power conversion device which achieves reductions in switching loss due to a reverse recovery current and heat generation loss. Specifically disclosed is a power conversion device provided with a cascode element configured by electrically connecting a normally-on switching element and a normally-off switching element in series and connecting a gate terminal of the normally-on switching element and a source terminal of the normally-off switching element via a cascode connection diode, and a high-speed diode electrically connected in parallel with the cascode element and having a cathode region connected to a positive electrode terminal and an anode region connected to a negative electrode terminal.Type: ApplicationFiled: December 20, 2011Publication date: April 12, 2012Applicants: Central Research Institute of Electric Power Ind., KABUSHIKI KAISHA TOSHIBAInventors: Atsuhiko KUZUMAKI, Hiroshi MOCHIKAWA, Takeru MURAO, Masahiro TAKASAKI, Tadao ISHIKAWA, Toshiaki KIKUMA
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Patent number: 6994614Abstract: A metal-bonded grinding tool including a base and abrasive grains bonded to the base by means of a metal bond matrix containing a Cu alloy as a main component. A content of at least one of an alloy phase, a mixed phase, and an intermetallic compound of Zr and Ti in the metal bond matrix is in a range of 3.8 to 19.2 wt %.Type: GrantFiled: August 26, 2003Date of Patent: February 7, 2006Assignee: Tenryu Seikyo Kabushiki KaishaInventors: Sokichi Takemura, Tadao Ishikawa
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Publication number: 20040043716Abstract: A metal-bonded grinding tool including a base and abrasive grains bonded to the base by means of a metal bond matrix containing a Cu alloy as a main component. A content of at least one of an alloy phase, a mixed phase, and an intermetallic compound of Zr and Ti in the metal bond matrix is in a range of 3.8 to 19.2 wt %.Type: ApplicationFiled: August 26, 2003Publication date: March 4, 2004Applicant: TENRYU SEIKYO KABUSHIKI KAISHAInventors: Sokichi Takemura, Tadao Ishikawa
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Patent number: 6579332Abstract: A metal-bonded grinding tool including a base, and abrasive grains bonded to the base by a bond matrix containing Cu alloy as a main component. The bond matrix further contains a powder selected from the group consisting of Ti, Al, and a mixture thereof. An average grain protrusion is set to 30% or more of an average grain diameter, and an average grain spacing is set to 200% or more of the average grain diameter.Type: GrantFiled: July 7, 2000Date of Patent: June 17, 2003Assignee: Tenryu Seikyo Kabushiki KaishaInventors: Sokichi Takemura, Tadao Ishikawa
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Patent number: 6526960Abstract: A wire-saw constituted by a rope-like core wire and a cylindrical coil-like saw-wire body wounded around the core wire, and a large number of abrasive grains firmly fixed to the saw-wire body by metal. Problems of conventional wire-saws, such as unstable working performance, a short tool life, low safety and low reliability, and so on, are solved.Type: GrantFiled: February 13, 2001Date of Patent: March 4, 2003Assignee: Asaoka Co., Ltd.Inventors: Toshihiko Asada, Tadao Ishikawa
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Publication number: 20010035173Abstract: A wire-saw constituted by a rope-like core wire and a cylindrical coil-like saw-wire body wounded around the core wire, and a large number of abrasive grains firmly fixed to the saw-wire body by metal. Problems of conventional wire-saws, such as unstable working performance, a short tool life, low safety and low reliability, and so on, are solved.Type: ApplicationFiled: February 13, 2001Publication date: November 1, 2001Inventors: Toshihiko Asada, Tadao Ishikawa
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Patent number: 5289206Abstract: An XY plotter includes a pair of grip and pinch rollers for feeding recording paper in one direction while gripping the recording paper therebetween, a pen carriage arranged to be movable in the direction perpendicular to the one direction, a pen supported by the pen carriage for performing recording on the recording paper, a grip roller shaft provided parallel to the traveling direction of the pen carriage, the grip roller shaft having a non-circular section, a movable stand arranged so that the position thereof is adjustable in the longitudinal direction of the grip roller shaft, and the grip and pinch roller including a movable partial grip roller and a pinch roller, the movable partial grip roller being mounted on the movable stand so that the movable partial grip roller is not rotatable relative to the grip roller shaft but is movable on the grip roller shaft in the longitudinal direction thereof, the pinch roller being supported on the movable stand so that the pinch roller is made to come into contactType: GrantFiled: October 9, 1991Date of Patent: February 22, 1994Assignee: Iwatsu Electric Co., Ltd.Inventors: Tadao Ishikawa, Nazuhiko Sanda, Ryoji Hirakata, Kiyokatsu Sugiyama
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Patent number: 5123217Abstract: A drill for use in drilling hard and brittle materials includes a shank and a drilling portion attached to one end of the shank. The drilling portion includes a tapered primary cutting edge, a first secondary cutting surface extending from the primary cutting edge and having an angle of taper substantially identical to that of the primary cutting edge, and a second secondary cutting surface extending from the first secondary cutting surface and containing a line substantially parallel to the central axis of the drill. The primary cutting edge has a first abrasive grain layer, and the first and second secondary cutting surfaces both have a second abrasive grain layer. The first and second abrasive grain layers both have a binder made of material selected from the group consisting of metal, resin and glass. Each abrasive grain in the first abrasive grain layer has a diameter greater than that of each abrasive grain in the second abrasive grain layer.Type: GrantFiled: August 29, 1990Date of Patent: June 23, 1992Assignee: Kabushiki Kaisha FujikoshiInventors: Tadao Ishikawa, Yutaka Yoshida, Toshiyuki Sunakoda