Patents by Inventor Donald W. Higgins

Donald W. Higgins 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: 6895178
    Abstract: The present invention provides a vapor delivery system and method for efficiently producing water vapor on demand. More particularly, the present invention produces low-temperature water vapor, without the formation of ice, by maintaining a sufficient volume of water at a sufficient temperature within a vaporizer chamber when the pressure in the vaporizer chamber is lowered.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: May 17, 2005
    Assignee: MKS Instruments, Inc.
    Inventors: Youfan Gu, Paul Dozoretz, Benjamin Goss, David Neumeister, James Mueller, Donald W. Higgins
  • Publication number: 20030063901
    Abstract: The present invention provides a vapor delivery system and method for efficiently producing water vapor on demand. More particularly, the present invention produces low-temperature water vapor, without the formation of ice, by maintaining a sufficient volume of water at a sufficient temperature within a vaporizer chamber when the pressure in the vaporizer chamber is lowered.
    Type: Application
    Filed: July 16, 2002
    Publication date: April 3, 2003
    Inventors: Youfan Gu, Paul Dozoretz, Benjamin Goss, David Neumeister, James Mueller, Donald W. Higgins
  • Patent number: 4545587
    Abstract: A multiple-shaft coaxial ferrofluid seal apparatus which comprises: a nonmagnetic housing; a central shaft element; and one or more successively coaxial shaft elements about the central shaft element with one or more of the coaxial shaft elements composed of a nonmagnetically permeable shaft section between a first and second magnetically permeable shaft sections. The seal apparatus includes an axial polarized annular permanent magnet together with first and second pole piece elements, the pole piece elements generally aligned with the magnetically permeable shaft sections to provide for a single magnetic structure within the housing and for a closed-loop magnetic flux to retain ferrofluid as a ferrofluid seal between the coaxial shaft elements which provides for hermetic sealing of the rotary motion of two or more of the coaxial shaft elements employing a single magnetic structure. The multiple-shaft coaxial ferrofluid seal apparatus also includes rotary bearings for the coaxial and central shaft element.
    Type: Grant
    Filed: November 20, 1984
    Date of Patent: October 8, 1985
    Assignee: Ferrofluidics Corporation
    Inventor: Donald W. Higgins