Patents by Inventor Wilhelmus F. Kragtwijk

Wilhelmus F. Kragtwijk 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: 5035860
    Abstract: The invention relates to a portable detection kit including a number of detection strips and at least one device for breaking reservoirs within the detection strips. The detection strips detect and identify chemical air contaminants and comprise a holder. The holder has a plurality of spaced carriers which are capable of absorbing the air contaminants and optionally comprise reagents which can be influenced by the air contaminants. The holder further has a plurality of color-producing agents opposite to the carriers. The agents, in contact with the absorbed air contaminants or with the reagents, can cause a color reaction in the presence of a liquid. The color-producing agents, which are dissolved in the quantities of liquid required for the color reaction, are held in closed reservoirs having easily breakable walls.
    Type: Grant
    Filed: February 20, 1990
    Date of Patent: July 30, 1991
    Assignee: Duphar International Research B.V.
    Inventors: Adriaan Kleingeld, Kees R. Kooijmans, Wilhelmus F. Kragtwijk