Patents by Inventor Hilbert D. Dahl

Hilbert D. Dahl 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: 4381161
    Abstract: A slurry recovery sump apparatus is formed from a substantially vertical sidewall and a substantially circular horizontal cross-section and includes a bottom. A support extends diametrically across the sump and above the sump, a material input is mounted between the sidewall and the vertical axis of the sump and is attached to the support, a slurry removal apparatus is mounted to the support between the sidewall and the sump vertical axis on the opposite side from the material input. Apparatus is provided for rotating the sump support around the vertical axis and additional apparatus is provided for moving the sump removal apparatus in a prescribed manner to empty the material being deposited into the sump by the material input.
    Type: Grant
    Filed: October 31, 1980
    Date of Patent: April 26, 1983
    Assignee: Conoco Inc.
    Inventors: Richard E. Doerr, Hilbert D. Dahl, Ronald W. Umphrey
  • Patent number: 4305474
    Abstract: A device for providing directional control to a borehole being drilled. The device is used with a drilling system including a drill string, a downhole motor and a bit rotated by the downhole motor. The device exerts a deflecting force perpendicular to the axis of the drill string when a lower than normal thrust is imposed on the drill string, and exerts an opposite perpendicular force when a higher than normal thrust is imposed on the drill string. When normal thrust is being used, the device does not cause deflection in either direction.
    Type: Grant
    Filed: February 4, 1980
    Date of Patent: December 15, 1981
    Assignee: Conoco Inc.
    Inventors: Nathandale Farris, Hilbert D. Dahl
  • Patent number: 3981541
    Abstract: In order to concentrate coal slurry from a plurality of mine faces being pumped through a plurality of individual pipes, a shallow sump is formed by digging a trench along a mine tunnel and the individual pipes empty into the sump. The product, such as coal, is allowed to settle to the bottom where it is picked up and pumped out of the mine at a controlled concentration, thereby improving the pumping efficiency of the pipeline system.
    Type: Grant
    Filed: April 15, 1974
    Date of Patent: September 21, 1976
    Assignee: Continental Oil Company
    Inventors: Richard E. Doerr, David L. McCain, Hilbert D. Dahl
  • Patent number: 3942841
    Abstract: An underground, improved slurry transportation system consists of a first and second vertical cavity. Both cavities have a vent means to the surface of the earth. Slurry input means from a plurality of mine faces communicates with the upper portion of the first vertical cavity and slurry output means communicates with the lower portion of the first vertical cavity. A pump connected to the slurry outlet forces the slurry from underground through a slurry handling pipe system to a preparation plant located on the surface of the earth.Water is added to the second vertical cavity by an inlet communicating with the upper portion of the cavity. Water is also provided to the first cavity, and valves are provided to add water to either the first or second cavity upon demand. A decant system is also provided between the first and second cavities to remove any excess water that may accumulate in the first cavity.
    Type: Grant
    Filed: April 23, 1974
    Date of Patent: March 9, 1976
    Assignee: Continental Oil Company
    Inventors: David L. McCain, Hilbert D. Dahl