Patents by Inventor L. David Engel

L. David Engel 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: 5305492
    Abstract: The brush element (10) includes a base (14), the base (14) including a connecting portion (18) at one end (16) thereof, which is capable of receiving the lever arm (15) of a vibrating toothbrush. Successive lateral rows of spaced bristles (19-27) are anchored in the brush base (14), in a pattern comprising two successive rows of full length bristles which are configured so that the tips of each two rows form a peak, followed by a third row of shorter bristle portions which are approximately 0.2 inch shorter than the full length bristles.
    Type: Grant
    Filed: November 3, 1992
    Date of Patent: April 26, 1994
    Assignee: Optiva Corporation
    Inventors: David Giuliani, L. David Engel
  • Patent number: 4787847
    Abstract: A method and apparatus for demobilizing the motile subgingival bacteria and for removing soft plaque from the teeth on a substantially daily basis as a means to prevent, treat and/or limit periodontal diseases. A piezoelectric multimorph transducer is used to generate low-energy vibrations, these vibrations are applied to the teeth and gingival fluids to cause mild cavitation within the fluid to remove subgingival plaque and to demobilize motile bacteria. An electronic circuit for driving the transducer at its resonant frequency or multiples thereof and for electrically isolating the user are included.
    Type: Grant
    Filed: March 26, 1985
    Date of Patent: November 29, 1988
    Assignee: The University of Washington
    Inventors: Roy W. Martin, L. David Engel, Joseph M. Miller