Patents Examined by Carol S. Bordar
  • Joining structures for metal pipes
    Patent number: 4930816
    Abstract: A joining structure for metal pipes to be applied in each passage hole of a pipe fitting. This structure can save time in pipe fitting work, and can reinforce the mutual joined condition of a pipe and a pipe fitting.
    Type: Grant
    Filed: May 17, 1989
    Date of Patent: June 5, 1990
    Inventor: Hwang Biing-Yih