Patents by Inventor Dale T. Lehman

Dale T. Lehman 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: 6837678
    Abstract: An impeller for a molten metal pump includes a base and a plurality of vanes having openings for flow of molten metal there through during pumping. Alternatively, or in combination with the vane openings, a single drain opening extending through the base of the impeller may be provided remote of the rotational axis of the impeller. In another embodiment, an impeller provides axial and radial pumping. The multiflow impeller includes at least one pumping chamber inclined into the direction of rotation to provide axial pumping.
    Type: Grant
    Filed: September 25, 2003
    Date of Patent: January 4, 2005
    Inventor: Dale T. Lehman
  • Patent number: 6755614
    Abstract: An impeller for a molten metal pump includes a base and a plurality of vanes having openings for flow of molten metal there through during pumping. Alternatively, or in combination with the vane openings, a single drain opening extending through the base of the impeller may be provided remote of the rotational axis of the impeller. In another embodiment, an impeller provides axial and radial pumping. The multiflow impeller includes at least one pumping chamber inclined into the direction of rotation to provide axial pumping.
    Type: Grant
    Filed: October 16, 2002
    Date of Patent: June 29, 2004
    Inventor: Dale T. Lehman
  • Patent number: 6562286
    Abstract: A molten metal pump includes a base member submerged in the molten metal, a support member supported above the level of the molten metal by a post extending from the base member through a clearance bore in the support member and a coupling securing the post to the support member. The coupling is mounted to the support surface and includes gripping members operable to a locked position engaging the upper end of the post and to an unlocked position releasing the post. The coupling is aligned with the clearance bore in the support member to permit the post to be assembled or disassembled by axial movement through the clearance bore when the coupling is in the unlocked position.
    Type: Grant
    Filed: March 13, 2001
    Date of Patent: May 13, 2003
    Inventor: Dale T. Lehman
  • Patent number: 6468039
    Abstract: An impeller for a molten metal pump includes a base and a plurality of vanes having openings for flow of molten metal there through during pumping, Alternatively, or in combination with the vane openings, a single drain opening extending through the base of the impeller may be provided remote of the rotational axis of the impeller. In another embodiment, an impeller provides axial and radial pumping. The multiflow impeller includes at least one pumping chamber inclined into the direction of rotation to provide axial pumping.
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: October 22, 2002
    Inventor: Dale T. Lehman
  • Patent number: 6457940
    Abstract: An impeller for a molten metal pump includes an exterior bearing mounting surface that is trued about the axis of the impeller and drive shaft assembly. Another impeller arrangement includes a pumping chamber having an axis offset from the impeller axis to achieve a volute pumping arrangement. In a further arrangement, the impeller is provided with peripheral pumping chambers intersecting the peripheral surface of the impeller. In each of the foregoing arrangements, a plate may be fixed to the pump drive shaft at a location axially spaced from the impeller inlet to screen debris and to pump molten metal to the impeller inlet.
    Type: Grant
    Filed: July 21, 2000
    Date of Patent: October 1, 2002
    Inventor: Dale T. Lehman
  • Patent number: 4244423
    Abstract: A heat exchanger comprising an elongated tubular cylindrical member having fluid ingress and egress openings adjacent to its opposite ends and external flanges at opposite ends one of which flanges has a counterbore facing in the direction away from the cylindrical member. A plurality of graphite tubes within the cylindrical member having their opposite ends connected to graphite headers one of which is connected through a graphite end member to one end of the cylindrical member and the other of which has an outside diameter slightly less than the inside diameter of the cylindrical member and within which it is slidable or floats. The floating header has an external circumferential groove with outwardly inclined ends. A seal is provided at the end of the cylindrical member at which the floating header is located which seal includes packing in the counterbore in the adjacent flange and a gland member slidable on the floating header and adjustable towards the flange.
    Type: Grant
    Filed: July 17, 1978
    Date of Patent: January 13, 1981
    Inventors: Bruno H. Thut, Dale T. Lehman
  • Patent number: 4119141
    Abstract: A heat exchanger comprising an elongated tubular cylindrical member having fluid ingress and egress openings adjacent to its opposite ends and external flanges at opposite ends one of which flanges has a counterbore facing in the direction away from the cylindrical member. A plurality of graphite tubes within the cylindrical member having their opposite ends connected to graphite headers one of which is connected through a graphite end member to one end of the cylindrical member and the other of which has an outside diameter slightly less than the inside diameter of the cylindrical member and within which it is slidable or floats. The floating header has an external circumferential groove with outwardly inclined ends. A seal is provided at the end of the cylindrical member at which the floating header is located which seal includes packing in the counterbore in the adjacent flange and a gland member slidable on the floating header and adjustable towards the flange.
    Type: Grant
    Filed: May 12, 1977
    Date of Patent: October 10, 1978
    Inventors: Bruno H. Thut, Dale T. Lehman