Patents by Inventor Douglas L. Tompkins

Douglas L. Tompkins 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: 4030498
    Abstract: A contamination resistant syringe is provided in which two sealing rings are axially spaced from each other. The sealing rings are prevented from sweeping the same area and there is no communication between the chamber defined by the two sealing rings and the discharge area forward of the inner sealing ring. In this manner, contamination which might enter from the rear of the barrel will be prevented from contact with the inner ssealing ring.
    Type: Grant
    Filed: July 22, 1976
    Date of Patent: June 21, 1977
    Assignee: Baxter Travenol Laboratories, Inc.
    Inventor: Douglas L. Tompkins