Patents by Inventor Eckhard Zwirner

Eckhard Zwirner 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).

  • Pressure spring
    Patent number: 4017062
    Abstract: A helical valve spring has terminal coils whose diameter and pitch are different from those of adjacent coils in the main body of the spring. The part of the spring lying between the terminal coil and the adjacent coil in the main body of the spring constitutes a transition zone. When the associated valve is opened, i.e., when the spring is in its maximum state of compression, a portion of the transition zone is in contact with a portion of the adjacent coil in the main body of the spring. This contact damps the natural vibration of the spring.
    Type: Grant
    Filed: September 18, 1975
    Date of Patent: April 12, 1977
    Assignee: Stumpp & Schule KG
    Inventor: Eckhard Zwirner