Patents by Inventor Emil J. Kvall

Emil J. Kvall 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: 4280491
    Abstract: A powered air respirator which provides hardhat (safety helmet), respiratory, eye and face protection and comprises a hardhat, a shell member spaced from and overlying the hardhat, air filtering means in the space between the shell member and the hardhat, a face shield assembly attached to and depending from the front of the shell member, a transparent face shield in said face shield assembly, face sealing means on the peripheral edge of said face shield assembly to seal against a user's face from temple to temple and an air circulating means located in the rear portion of the shell member is disclosed.
    Type: Grant
    Filed: March 7, 1980
    Date of Patent: July 28, 1981
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Richard C. Berg, Emil J. Kvall