Patents by Inventor Alan Norman Greenwood

Alan Norman Greenwood 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).

  • Intrinsically safe power supply apparatus
    Patent number: 3955132
    Abstract: A battery powered circuit has the battery source divided into serially connected sections and each section is shunted by a diode. The breakdown of one section gives only a low powered spark under fault conditions. The circuit can be used in hazardous environments such as coal mines or petrol installations.
    Type: Grant
    Filed: June 18, 1974
    Date of Patent: May 4, 1976
    Assignee: Coal Industry (Patents) Limited
    Inventor: Alan Norman Greenwood