Patents by Inventor John D. Kratzer

John D. Kratzer 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).

  • Engine heating system
    Patent number: 4520769
    Abstract: An engine preheating system comprising a pair of oppositely disposed burner devices operated by propane gas, a pair of oppositely disposed cylindrical combustion chambers with a cylindrical coolant jacket therearound, and a central cylindrical stack connected to the combustion chambers with a coolant jacket therearound connected to the other coolant jacket.
    Type: Grant
    Filed: July 30, 1984
    Date of Patent: June 4, 1985
    Inventor: John D. Kratzer