Patents by Inventor John A. Imsdahl

John A. Imsdahl 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: 6338471
    Abstract: The present disclosure relates to an evaporative cooler for a turbine intake system. The evaporative cooler includes a reservoir for holding water, a media, a manifold for dispersing the water from the reservoir above the media, a manifold flow line extending from the reservoir to the manifold, a collector for collecting the water below the media, and a pump for pumping the water through the manifold flow line from the reservoir to the manifold. The evaporative cooler also includes a return line for returning the water from the collector to the reservoir, at least one water supply line for supplying the water to the reservoir, and a valve structure for controlling flow through the at least one water supply line. The evaporative cooler further includes a level sensor for indicating whether a top surface of the water within the reservoir is: (1) above or below a first water line; and (2) above or below a second water line positioned below the first water line.
    Type: Grant
    Filed: November 18, 1998
    Date of Patent: January 15, 2002
    Assignee: Donaldson Company, Inc.
    Inventors: John A. Imsdahl, Michael J. McCarthy
  • Patent number: 6206348
    Abstract: The present disclosure relates to an evaporative cooler including first and second trays each having a longitudinal axis. Each tray includes a bottom wall and two side walls that project upward from the bottom wall and extend generally parallel to the longitudinal axis of each tray. Each tray also includes two end walls that project upward from the bottom wall and extend between the side walls. Each tray further includes spaced apart cooler media retaining members that are generally parallel to the longitudinal axis of each tray. The trays are positioned in an end-to-end relationship such that the longitudinal axes of the trays are generally aligned with one another, and one of the end walls of the first tray is positioned adjacent to one of the end walls of the second tray. The evaporative cooler also includes an elongated clip adapted to extend the between the adjacent end walls of the first and second trays for inhibiting water leakage between the adjacent walls.
    Type: Grant
    Filed: November 18, 1998
    Date of Patent: March 27, 2001
    Assignee: Donaldson Company, Inc.
    Inventors: John A. Imsdahl, Leon R. H. Cuvelier, Alan John Spychalla
  • Patent number: 5003431
    Abstract: An apparatus for moving a module in a guide channel includes levers which cooperate with cams associated therewith and contacting edges extending from the guide channels to apply forces for positioning the module. These forces are coupled to movable wedges, guided by wedges fixed to the module, which contact the walls of the guiding channels to clamp the module. Clamping forces are maintained by compressible elements such as Belleville washers or suitable springs coupled to the wedges fixed on the module.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: March 26, 1991
    Assignee: Unisys Corporation
    Inventor: John A. Imsdahl
  • Patent number: 4796432
    Abstract: A liquid cryogen dewar is constructed in which two or more liquid cryogen chambers are suspended within a case wherein the innermost cryogens have a higher boiling, or sublimation, temperature than the cryogen in the next outermost chamber. The chambers may contain liquid helium, liquid nitrogen and solid CO.sub.2 proceeding from the innermost to the outermost chamber. Superconducting electronic circuitry such as SQUID devices may be connected to the outer case of the liquid helium cryogen chamber. An isothermal shield is also suspended outside the helium chamber. The elements of the dewar are supported by glass epoxy rods and polyester cords of low thermal conductivity. A fill and exhaust port is provided which communicates with fill and exhaust tubes that are heat sunk to various locations of the rods and the Dacron cords.
    Type: Grant
    Filed: October 9, 1987
    Date of Patent: January 10, 1989
    Assignee: Unisys Corporation
    Inventors: Dale J. Fixsen, Roger N. Hastings, John A. Imsdahl
  • Patent number: 4750631
    Abstract: In order to avoid the sloshing of liquid within a container caused by movement of the container, the single bulk volume of the liquid is retained in the form of a plurality of separated mini-volumes. This is accomplished by providing a chamber formed by upper and lower plates and an interconnecting sidewall. A plurality of elongated, adjacent mini-chambers are provided within the chamber aligned in side-by-side relationship with the sidewall. The mini-chambers are formed by a honeycomb medium of acoustical material having one end sealed closed. The medium has no measurable magnetic susceptability and is formed of a paper material treated with a heat resistant phenolic resin. When placed within an insulated housing including isothermal shields, the chamber is useful in cryogenic applications such as, for example, storing liquid helium.
    Type: Grant
    Filed: July 21, 1986
    Date of Patent: June 14, 1988
    Assignee: Sperry Corporation
    Inventors: Roger N. Hastings, John A. Imsdahl