Patents by Inventor Karl H. Nagel

Karl H. Nagel 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).

  • Swimming pool alarm system
    Patent number: 4187502
    Abstract: A swimming pool alarm system of the pressure transducer type employs an omnidirectional hydrophone which is held immersed in the swimming pool by means that mechanically decouples the hydrophone.
    Type: Grant
    Filed: December 12, 1977
    Date of Patent: February 5, 1980
    Inventors: Frank O. Beverly, Karl H. Nagel