Patents by Inventor Mark E. Kraft

Mark E. Kraft 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: 5490679
    Abstract: A mechanical end face seal having a first seal ring with a generally radially extending sealing face, a second seal ring having a sealing face opposite to and in mating relation with the sealing face of the first seal ring, the second seal ring having a generally radially extending back face removed from and oppositely disposed to said sealing face, the back face including an annular shoulder at the outer diameter defined by an annular axially extending flange which forms an annular section between the flange and the ring outer diameter. The annular section displaces the ring centroid further toward the seal interface and also toward the ring inner diameter, thus minimizing axial rotational and pressure forces acting on the axially movable ring to stabilize the ring. Stabilization of the ring permits balancing the seal to over 80% for dry-running with a gas lubricant at over 300 psig pressure differential and high rotational speeds.
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: February 13, 1996
    Assignee: John Crane Inc.
    Inventors: Thomas Borrino, Mark E. Kraft