Patents by Inventor Herbert F. Schefers

Herbert F. Schefers 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: 4910906
    Abstract: A method and apparatus using a pressurizable bladder for maintaining a hole open in outdoor ice atop a body of water. The apparatus has a top plug with an air tube and valve, an elongate bladder extending down from the plug, and radially spaced apart longitudinal cords in the bladder which constrains elongate growth but enable diameter growth of the bladder. The method has steps of placing the ice plug over a hole, weighing the ice plug, inflating the bladder to a pressure of about 2-3 PSIG, and restraining the ice plug in the hole with a diametrically expanded lower part of the bladder underneath the ice.
    Type: Grant
    Filed: January 30, 1989
    Date of Patent: March 27, 1990
    Inventors: Herbert F. Schefers, James O. Schefers