Patents by Inventor Fong S. Hsu

Fong S. Hsu 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).

  • Ring shaped hanging lock with replaceable core
    Patent number: 4998423
    Abstract: A ring shaped hanging lock which includes a casing, a replaceable core and a ring shaped shackle. A tool can be used to remove the core when the shackle is in an intermediate position. But when the lock is open or closed, an opening is obstructed by the shackle such that the tool cannot be inserted into the casing.
    Type: Grant
    Filed: January 5, 1990
    Date of Patent: March 12, 1991
    Inventor: Fong S. Hsu