Patents by Inventor Phuong N. Mai

Phuong N. Mai 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).

  • Foot and leg exercise device
    Patent number: 5069445
    Abstract: A foot-leg exercise device that includes two foot-supporting platforms individually swingably connected to the base structure. A spring within each platform provides resistance against downward deflection of the platform by the person's foot. Spring resistance can be varied by a manual screw adjustment means associated with each platform.
    Type: Grant
    Filed: September 13, 1990
    Date of Patent: December 3, 1991
    Inventor: Phuong N. Mai