Patents by Inventor Edgar H. Nelson

Edgar H. Nelson 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 of assembling a butterfly damper capable of fully stopping the flow of air and/or gases
    Patent number: 5979053
    Abstract: A butterfly damper for installation in duct work through which air and/or gases will be flowing either under a positive or negative pressure has: an outer cylindrical surface structure made of a strong material; an inner cylindrical surface structure made of a resilient material; a circumferential portion of compressible material, which is always tending to return to the non-compressed form thereof, which is initially compressed between the outer cylindrical surface structure and the inner cylindrical surface structure, whereby the inside diameter of the duct body portion, initially, is uniform throughout the length thereof, and, thereafter, when the initial compressive force becomes less effective, the compressive material expands causing radially inward movement of adjacent circumferential portions of the inner cylindrical surface structure; a blade to be moved across the flow of air and/or gases into sealing contact with the radially inwardly moved circumferential portions of the inner cylindrical surface
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: November 9, 1999
    Inventors: J. Michael Schaeffer, Edgar H. Nelson, Kirk T. Nelson
  • Butterfly damper
    Patent number: 5876015
    Abstract: A butterfly damper for installation in duct work through which air and/or gases will be flowing either under a positive or negative pressure has: an outer cylindrical surface structure made of a fixed strong material; an inner flexible cylindrical surface structure made of a resilient material; a circumferential portion of compressible material, which is always tending to return to the non-compressed form thereof, which is initially compressed between the outer cylindrical surface structure and the inner cylindrical surface structure, whereby the inside diameter of the duct body portion, initially, is uniform throughout the length thereof, and, thereafter, when the initial compressive force becomes less effective, the compressive material expands causing radially inward movement of adjacent circumferential portions of the inner flexible cylindrical surface structure; a blade to be moved across the flow of air and/or gases into sealing contact with the radially inwardly moved circumferential portions of the in
    Type: Grant
    Filed: August 3, 1995
    Date of Patent: March 2, 1999
    Inventors: J. Michael Schaeffer, Edgar H. Nelson, Kirk T. Nelson