Patents by Inventor Ronald F. Olmstead

Ronald F. Olmstead 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: 4741664
    Abstract: An axial flow liquid pump comprises an outer tube, an inner tube positioned within the outer tube, and a driven shaft journaled within the inner tube. An impeller is secured near to the lower end of the shaft. A conduit delivers liquid to be pumped from the exterior of the outer tube to the lower end of the inner tube. The conduit is sized for permitting liquid to be drawn into said impeller such that the pressure in the vicinity of the lower end of the inner tube is equal or less than the pressure at the exterior of the outer tube near the conduit intake but sufficient not to draw air down through the inner tube.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: May 3, 1988
    Assignee: Thompson-Chemtrex, Inc.
    Inventors: Ronald F. Olmstead, H. David Bowes