Patents by Inventor Frederick B. Essex

Frederick B. Essex 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).

  • Method to make safe an ungrounded electrical receptacle and apparatus therefor
    Patent number: 5269697
    Abstract: A method is taught whereby an ungrounded safety electrical receptacle or outlet is made incompatible with a three-pronged safety plug, thereby to warn the user that the receptacle is not grounded. The method employs various fillers to fill or otherwise block entry to the hole in the outlet that receives the grounding prong of the safety plug. Labelling of the receptacle employing the filler is included. The various fillers for use in the method are also claimed, as are labelling techniques.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: December 14, 1993
    Inventor: Frederick B. Essex