Patents by Inventor Hoe Gwan Yoo

Hoe Gwan Yoo 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).

  • Height-adjustable folding work platform
    Patent number: 7690316
    Abstract: A height adjustable folding work platform includes two footplates, a footplate folding portion that foldably connects the footplates, two legs, and two leg folding portions, each of which connect the leg to the outer end of the footplate. Each of the legs includes two support legs and a plurality of cross members that connect the support legs. The leg folding portion selectively engages with one of the cross members so that the height of the height adjustable folding work platform is adjusted.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: April 6, 2010
    Inventors: Hoe Gwan Yoo, Jung Hwan Lim
  • Combined stepladder and hand truck assembly
    Patent number: 6651774
    Abstract: A combined stepladder and hand truck assembly is provided. The assembly comprises a first frame having two side rails, a second frame pivotally attached to the back side of the first frame and having two side rails, and a third frame pivotally attached to the front side of the first frame and having two side rails. Steps and bars are provided so that they form a parallel link together with the side rails of the first frame. Two casters attached at the lower end of the first frame. A tool tray is provided at the lower end of the third frame. The tray is kept vertical to the frames when the assembly is used as a hand truck, and is kept horizontal when the assembly is used as a stepladder and the third frame is rotated upward to support the tool tray in a high position.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: November 25, 2003
    Inventor: Hoe Gwan Yoo
  • COMBINED STEPLADDER AND HAND TRUCK ASSEMBLY
    Publication number: 20030155178
    Abstract: A combined stepladder and hand truck assembly is provided. The assembly comprises a first frame having two side rails, a second frame pivotally attached to the back side of the first frame and having two side rails, and a third frame pivotally attached to the front side of the first frame and having two side rails. Steps and bars are provided so that they form a parallel link together with the side rails of the first frame. Two casters attached at the lower end of the first frame. A tool tray is provided at the lower end of the third frame. The tray is kept vertical to the frames when the assembly is used as a hand truck, and is kept horizontal when the assembly is used as a stepladder and the third frame is rotated upward to support the tool tray in a high position.
    Type: Application
    Filed: February 19, 2002
    Publication date: August 21, 2003
    Inventor: Hoe Gwan Yoo