Patents by Inventor Alan Hiiesalu

Alan Hiiesalu 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).

  • Battery condition indicator
    Patent number: 4989453
    Abstract: A battery condition readout device is disclosed. A series of slides of varying densities float or sink according to the amount of charge. An optical system permits slide position to be seen at a point external to the battery.
    Type: Grant
    Filed: November 6, 1989
    Date of Patent: February 5, 1991
    Inventor: Alan Hiiesalu