Patents by Inventor Sigurd Alfons Backlund

Sigurd Alfons Backlund 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).

  • Breathing mask, especially a half mask or a full mask provided with an inner mask
    Patent number: 4057057
    Abstract: A gas mask, especially a half mask or a full mask provided with an inner mask, and having protective glasses or spectacles and means for attaching them to the half mask or directly to the inner mask.
    Type: Grant
    Filed: September 22, 1975
    Date of Patent: November 8, 1977
    Assignee: Kemira Oy
    Inventor: Sigurd Alfons Backlund
  • Exhaust valve of respiratory mask
    Patent number: D249279
    Type: Grant
    Filed: February 12, 1976
    Date of Patent: September 5, 1978
    Inventor: Sigurd Alfons Backlund