Patents by Inventor Kot F. Unrug

Kot F. Unrug 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).

  • Rock bolt overload warning device
    Patent number: 4410296
    Abstract: A washer is described which is used in the construction of the support for the roof of a mine. The washer is fabricated such that finger like projections rupture in stages as the tension on bolts and pressure in the strata of the roof of the mine increases beyond structurely safe limits. The rupturing of the washer emits audible warning signals and also provides a visual indication of an unsafe condition.
    Type: Grant
    Filed: October 30, 1981
    Date of Patent: October 18, 1983
    Inventor: Kot F. Unrug