Patents by Inventor Han Ok Choi

Han Ok Choi 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).

  • Hydraulic circuit for pipe layer
    Patent number: 9249812
    Abstract: Disclosed is a hydraulic circuit for a pipe layer, in which the generation of hydraulic shock in equipment is prevented when an operating device or a moving device is finely operated during combined work in a pipe-laying operation mode.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: February 2, 2016
    Assignee: VOLVO CONSTRUCTION EQUIPMENT AB
    Inventors: Man-Seuk Jeon, Han-Ok Choi
  • HYDRAULIC CIRCUIT FOR PIPE LAYER
    Publication number: 20130333367
    Abstract: Disclosed is a hydraulic circuit for a pipe layer, in which the generation of hydraulic shock in equipment is prevented when an operating device or a moving device is finely operated during combined work in a pipe-laying operation mode.
    Type: Application
    Filed: March 7, 2011
    Publication date: December 19, 2013
    Applicant: VOLVO CONSTRUCTION EQUIPMENT AB
    Inventors: Man-Seuk Jeon, Han-Ok Choi
  • Hydraulic flow sharing system for excavating and pipe laying work
    Patent number: 8424301
    Abstract: A hydraulic flow sharing system for excavating and pipe laying work is provided, which can prevent the abrupt change of a traveling speed during traveling through compulsory sharing of the flow rate applied to a working device and a traveling apparatus when a combined operation, in which the traveling apparatus and the working device such as a boom are simultaneously driven, is performed.
    Type: Grant
    Filed: August 5, 2009
    Date of Patent: April 23, 2013
    Assignee: Volvo Construction Equipment Holding Sweden AB
    Inventors: Han Ok Choi, Kyung Sub Lee
  • Hydraulic system for leveling apparatus in excavator and forestry equipment
    Patent number: 7753382
    Abstract: A hydraulic system for a leveling apparatus in excavator and forestry equipment is provided, whereby an upper frame of the equipment is kept in a horizontal state even if a lower frame of the equipment is on an inclined ground against a horizontal surface H. The hydraulic system a pair of first and second actuators and a pair of third and fourth actuators for rocking the lower part of the upper frame, first leveling control valves for simultaneously controlling extension and contraction of the first and second actuators, second leveling control valves for simultaneously controlling extension and contraction of the third and fourth actuators a reducing valve for discharging a reducing pilot signal pressure, and flow control valves for discharging the pilot signal pressure for the spool shifting of the first and second leveling control valves when a control signal is applied from a preset leveling controller.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: July 13, 2010
    Assignee: Volvo Construction Equipment Holding Sweden AB
    Inventor: Han Ok Choi
  • HYDRAULIC FLOW SHARING SYSTEM FOR EXCAVATING AND PIPE LAYING WORK
    Publication number: 20100031648
    Abstract: A hydraulic flow sharing system for excavating and pipe laying work is provided, which can prevent the abrupt change of a traveling speed during traveling through compulsory sharing of the flow rate applied to a working device and a traveling apparatus when a combined operation, in which the traveling apparatus and the working device such as a boom are simultaneously driven, is performed.
    Type: Application
    Filed: August 5, 2009
    Publication date: February 11, 2010
    Applicant: VOLVO CONSTRUCTION EQUIPMENT HOLDING SWEDEN AB
    Inventors: Han Ok Choi, Kyung Sub Lee
  • HYDRAULIC SYSTEM FOR LEVELING APPARATUS IN EXCAVATOR AND FORESTRY EQUIPMENT
    Publication number: 20090152025
    Abstract: A hydraulic system for a leveling apparatus in excavator and forestry equipment is provided, whereby an upper frame of the equipment is kept in a horizontal state even if a lower frame of the equipment is on an inclined ground against a horizontal surface H. The hydraulic system a pair of first and second actuators and a pair of third and fourth actuators for rocking the lower part of the upper frame, first leveling control valves for simultaneously controlling extension and contraction of the first and second actuators, second leveling control valves for simultaneously controlling extension and contraction of the third and fourth actuators a reducing valve for discharging a reducing pilot signal pressure, and flow control valves for discharging the pilot signal pressure for the spool shifting of the first and second leveling control valves when a control signal is applied from a preset leveling controller.
    Type: Application
    Filed: December 8, 2008
    Publication date: June 18, 2009
    Inventor: Han Ok CHOI