Patents by Inventor Karl Eric Leinfelt

Karl Eric Leinfelt 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).

  • Vacuum cleaner dust container filling indicator device
    Patent number: 4100878
    Abstract: An indicator mounted on a vacuum cleaner housing for showing at any given time the degree of filling of the dust container. The indicator includes bellows which are connected to both the outside of the dust container and the interior of the vacuum cleaner housing whereby the bellows are acted upon under the influence of the changing pressure differential to respectively expand or contract the bellows thereby indicating the degree of clogging of the dust container.
    Type: Grant
    Filed: December 2, 1976
    Date of Patent: July 18, 1978
    Assignee: Aktiebolaget Electrolux
    Inventor: Karl Eric Leinfelt
  • Combination dust container for vacuum cleaner and signalling device
    Patent number: 4070170
    Abstract: A combination dust container or bag for a vacuum cleaner and a signal indicator for alerting the user to the replacement of the dust bag. The communication between the interior of the dust bag and the signal indicator includes an air pervious part integral with the dust bag. The signal indicator also communicates with the enclosed area between the exterior of the dust bag and the interior of the vacuum cleaner housing. Furthermore, the signal indicator has a member which is movable therein as a result of the pressure difference between the interior and exterior of the dust bag.
    Type: Grant
    Filed: August 18, 1976
    Date of Patent: January 24, 1978
    Assignee: Aktiebolaget Electrolux
    Inventor: Karl Eric Leinfelt