Patents by Inventor Dale E. Stelz

Dale E. Stelz 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).

  • Refrigeration liquid with blue leak indicator and process of using same
    Patent number: 4436641
    Abstract: 1,4-Bis(2,4,6-trialkylanilino)anthraquinone wherein the alkyls on each anilino group are selected from the group consisting of methyl and ethyl and one of the three alkyls on each anilino group is different from the other two, e.g. 1,4-bis(2,6-diethyl-4-methylanilino)anthraquinone, is disclosed as an unusually effective blue dye suitable for use as a visual leak indicator in halocarbon refrigerants or in refrigeration liquids comprising a halocarbon refrigerant in admixture with a refrigeration oil.
    Type: Grant
    Filed: November 29, 1982
    Date of Patent: March 13, 1984
    Assignee: Racon Incorporated
    Inventors: Dale E. Stelz, Frank I. Carroll, Wilson M. Whaley
  • Refrigeration liquid with leak indicator and process of using same
    Patent number: 4369120
    Abstract: Compounds of the class represented by 1,4-bis(2-methyl-6-ethylanilino)anthraquinone, 1,4-bis(2,6-dimethylanilino)anthraquinone, and 1,4-bis(2,4,6-trimethylanilino)anthraquinone are disclosed as being unusually stable blue dyes suitable for use as visual leak indicators in refrigerants; e.g., in halocarbon refrigerants, or in refrigeration liquids comprising a halocarbon refrigerant in admixture with a refrigeration oil.
    Type: Grant
    Filed: May 21, 1981
    Date of Patent: January 18, 1983
    Assignee: Racon Incorporated
    Inventors: Dale E. Stelz, Wilson M. Whaley, Frank I. Carroll