Patents by Inventor Tadashi NISHIZAWA

Tadashi NISHIZAWA 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).

  • Publication number: 20230366178
    Abstract: A work machine includes a second pilot line that introduces a hydraulic fluid from a pilot hydraulic fluid source to a pilot valve bypassing a first gate lock valve, a second gate lock valve that is disposed on the second pilot line and that is configured to be switched to an open position for allowing the supply of the hydraulic fluid to the pilot valve or a closed position for interrupting the supply of the hydraulic fluid, and a controller that controls the second gate lock valve on the basis of a second remote operation signal transmitted from a remote operation apparatus and that controls the pilot valve according to a first remote operation signal transmitted from the remote operation apparatus. In a state where the first gate lock valve is at a closed position, the second gate lock valve is allowed to be controlled by the controller when stairs are in a retracted state, and is kept at the closed position irrespective of the second remote operation signal when the stairs are in an extended state.
    Type: Application
    Filed: February 3, 2022
    Publication date: November 16, 2023
    Inventors: Teppei SAITOH, Kouji FUJITA, Hideaki ITOU, Hidefumi ISHIMOTO, Ryu NARIKAWA, Tadashi NISHIZAWA
  • Publication number: 20230358014
    Abstract: Provided is a work machine that allows assisting a loading work without giving uncomfortable feeling to an operator. The control device 40 of the work machine 1 includes an allowable range calculation section 46 that calculates an allowable range indicating a range in which the front work device 2 is movable in a height direction allowed in a swing operation; an operation determining section 45 that determines whether the work machine 1 is under a convey operation; and an operation control section 4 that controls a turn operation of a boom 8 such that the position of the front work device 2 in the height direction remains within the allowable range when the work machine 1 is determined to be under the convey operation.
    Type: Application
    Filed: March 1, 2022
    Publication date: November 9, 2023
    Inventors: Ryu NARIKAWA, Kouji FUJITA, Hideaki ITOU, Hidefumi ISHIMOTO, Teppei SAITOH, Tadashi NISHIZAWA
  • Patent number: 11142891
    Abstract: Work efficiency is improved while necessary and sufficient monitoring on the surroundings of a working machine is performed. A working machine includes an undercarriage 132 on which an upperstructure 131 including a front working device is mounted in a swingable manner, and includes a surrounding monitoring device 200 that monitors surroundings. The surrounding monitoring device 200 has an information controller 161 that: sets a working region by use of terrain data and work states received from sensors detecting work states of the front working device of the working machine; calculates proximity for each of the obstacles around the working machine by use of the working regions and relative positions of each of obstacles and the working machine, the obstacles being detected by an obstacle sensor that detects obstacles around the working machine; and outputs a control instruction in accordance with the proximity.
    Type: Grant
    Filed: August 24, 2018
    Date of Patent: October 12, 2021
    Assignee: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Tadashi Nishizawa, Hiroshi Sakamoto, Takuya Naka
  • Publication number: 20200048871
    Abstract: Work efficiency is improved while necessary and sufficient monitoring on the surroundings of a working machine is performed. A working machine includes an undercarriage 132 on which an upperstructure 131 including a front working device is mounted in a swingable manner, and includes a surrounding monitoring device 200 that monitors surroundings. The surrounding monitoring device 200 has an information controller 161 that: sets a working region by use of terrain data and work states received from sensors detecting work states of the front working device of the working machine; calculates proximity for each of the obstacles around the working machine by use of the working regions and relative positions of each of obstacles and the working machine, the obstacles being detected by an obstacle sensor that detects obstacles around the working machine; and outputs a control instruction in accordance with the proximity.
    Type: Application
    Filed: August 24, 2018
    Publication date: February 13, 2020
    Inventors: Tadashi NISHIZAWA, Hiroshi SAKAMOTO, Takuya NAKA