Patents by Inventor Rindo Morikawa

Rindo Morikawa 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: 5161373
    Abstract: Disclosed is a hydraulic control valve system, for driving a plurality of hydraulic actuators by a single pump, including pressure compensation valves and a shuttle valve disposed in a vertical bore orthogonal to a lateral bore of a valve body, into which a spool of a direction switching valve is fitted. A load sensing chamber for introducing a load pressure of an actuator is formed at an intersection between the lateral bore and the vertical bore. An opening-side first pressure receiving surface of the pressure compensation valve confronts the load sensing chamber. The pressure compensation valve has an opening-side second pressure receiving surface contacting a pilot pressure in the vicinity of the opening-side first pressure receiving surface. Formed on the upper side of the pressure compensation valve are a closing-side first pressure receiving surface on which a bridge pressure acts and a closing-side first pressure receiving surface on which an external control pressure acts.
    Type: Grant
    Filed: June 19, 1991
    Date of Patent: November 10, 1992
    Assignees: Zexel Corporation, Hitachi Construction Machinery Co., Ltd.
    Inventors: Rindo Morikawa, Yusuke Kajita, Genroku Sugiyama
  • Patent number: 5161575
    Abstract: There is disclosed a direction selector valve having function of detecting load. The valve is used in a hydraulic system. A spool has two passage holes extending axially partially through the spool from both side ends. These two passage holes have their respective high-pressure holes. When the spool is in its neutral position, the high-pressure holes are closed off by spool hole walls between bridge ports and actuator ports. The two passage holes further include low-pressure holes which are in communication with tank ports via load check valves mounted in the passage holes, respectively. Guide holes are formed near the front end of one passage hole and in communication with a load-sensing port. A restriction portion is formed on the outer surface of the spool adjacently to the guide holes to control the flow from the load-sensing port to the tank ports. First guide holes and second guide holes which are close to each other are formed near the front end of the other passage hole.
    Type: Grant
    Filed: June 19, 1991
    Date of Patent: November 10, 1992
    Assignees: ZEXEL Corporation, Hitachi Construction Machinery Co., Ltd.
    Inventors: Rindo Morikawa, Kiyoshi Oyama, Toichi Hirata, Yusuke Kajita, Genroku Sugiyama
  • Patent number: 5025625
    Abstract: A hydraulic control system for driving a plurality of actuators basically includes directional control valves, and pressure compensation valves, and at least one detection valve, the directional valves and the pressure compensation valves both corresponding in number to the actuators. These valves are mounted or incorporated in a body. The body has a plurality of regions corresponding in number to the actuators. Each of the regions of the body has a first hole, and a second hole substantially perpendicularly intersecting the first hole. A load pressure chamber for receiving a load pressure of the corresponding actuator is formed at the intersection between the first and second holes of each region. A spool of the directional control valve is received in the first hole. A balance piston of the pressure compensation valve is received in that portion of the second hole disposed on one side of the load pressure chamber.
    Type: Grant
    Filed: November 7, 1989
    Date of Patent: June 25, 1991
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventor: Rindo Morikawa