Patents by Inventor Frederic G. Dewalt

Frederic G. Dewalt 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).

  • Method for producing a purple complex for the presence of lead using sodium rhodizonate without use of strong acid
    Patent number: 11442049
    Abstract: A method using ascorbic acid (Vitamin C) as part of a chemical test kit employing sodium rhodizonate as the coloring agent for producing a yellow-orange to purple color transition for detection of lead in various media eliminating the use of strong acid.
    Type: Grant
    Filed: July 25, 2019
    Date of Patent: September 13, 2022
    Inventors: Frederic G Dewalt, David C Cox
  • METHOD FOR PRODUCING A PURPLE COMPLEX FOR THE PRESENCE OF LEAD USING SODIUM RHODIZONATE WITHOUT USE OF STRONG ACID
    Publication number: 20210025859
    Abstract: A method using ascorbic acid (Vitamin C) as part of a chemical test kit employing sodium rhodizonate as the coloring agent for producing a yellow-orange to purple color transition for detection of lead in various media eliminating the use of strong acid.
    Type: Application
    Filed: July 25, 2019
    Publication date: January 28, 2021
    Applicant: QuanTech, Inc.
    Inventors: Frederic G. Dewalt, David C. Cox
  • Method for controlling the sensitivity and response point of chemical test kits for metals in paint and other media
    Patent number: 9128075
    Abstract: A method of changing the response level for any chemical test kits designed for the determination of a metal or compound (such as lead) in paint and other media is disclosed. The invention solves two common problems that exist with using chemical test kits for the detection of lead in paint or other coatings and media: (1) conversion of the paint sample into particles small enough to dissolve the metal in the sample; and, (2) controlling the amount of (paint) sample that gets exposed to the chemicals. This is accomplished by using a coffee grinder or equivalent tool plus a solid (food) product to break up the paint sample into small particles and at the same time dilute the concentration of the metal, while in solid form, down to a level that results in obtaining a positive response at the desired concentration.
    Type: Grant
    Filed: June 30, 2012
    Date of Patent: September 8, 2015
    Inventors: Frederic G Dewalt, David C. Cox
  • METHOD FOR CONTROLLING THE SENSITIVITY AND RESPONSE POINT OF CHEMICAL TEST KITS FOR METALS IN PAINT AND OTHER MEDIA
    Publication number: 20140004614
    Abstract: A method of changing the response level for any chemical test kits designed for the determination of a metal or compound (such as lead) in paint and other media is disclosed. The invention solves two common problems that exist with using chemical test kits for the detection of lead in paint or other coatings and media: (1) conversion of the paint sample into particles small enough to dissolve the metal in the sample; and, (2) controlling the amount of (paint) sample that gets exposed to the chemicals. This is accomplished by using a coffee grinder or equivalent tool plus a solid (food) product to break up the paint sample into small particles and at the same time dilute the concentration of the metal, while in solid form, down to a level that results in obtaining a positive response at the desired concentration.
    Type: Application
    Filed: June 30, 2012
    Publication date: January 2, 2014
    Applicant: QUANTECH, INC.
    Inventors: Frederic G. Dewalt, David C. Cox