Including Cord Patents (Class D21/481)
  • Folding loop string puzzle
    Patent number: D479735
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: September 16, 2003
    Inventor: Rob Hudson
  • Rope untangling game
    Patent number: D1101871
    Type: Grant
    Filed: April 3, 2025
    Date of Patent: November 11, 2025
    Inventor: Guangsheng Zhuang