Patents by Inventor John Skarman

John Skarman 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).

  • Patent number: 4021792
    Abstract: A smoke alarm having a smoke chamber with at least two inlet ports together with an array of louvered apertures and flue means to provide free access to the smoke chamber for smoke flowing in any direction within a hemispherical zone. A circuit employing photocells to measure smoke obscuration and reflection by means of an improved wheatstone bridge to sound a loud audible alarm. A relaxation oscillator coupled to a light source which is used for the optical portion of the smoke alarm. The oscillator produces an alarm to indicate failure of the light source, which alarm is distinguishable from the smoke alarm. A heat sink thermally coupled to the light source to induce filament vapors to condense on non-critical portions of the light source.
    Type: Grant
    Filed: June 23, 1975
    Date of Patent: May 3, 1977
    Assignee: Wellen Industries
    Inventors: Roy R. Ludt, Carl A. Eggert, John Skarman