Patents Represented by Attorney, Agent or Law Firm Tom L. Derry
  • Method and apparatus to control a turbocharger wastegate using exhaust pressure
    Patent number: 6564554
    Abstract: Engines having turbochargers with a mechanically actuated wastegate typically control the wastegate in response to the air pressure at an outlet of a compressor portion of the turbocharger. Some engine configurations don't provide enough compressor outlet pressure variation to suitably control the wastegate. In the present invention, a control strategy is provided for opening and closing a wastegate based on exhaust gas pressure.
    Type: Grant
    Filed: August 7, 2001
    Date of Patent: May 20, 2003
    Assignee: Caterpillar Inc
    Inventors: Robert L. Hercey, Donald W. Heston, David L. Lehman
  • Method and apparatus for preheating of combustion air for an internal combustion engine
    Patent number: 6536419
    Abstract: This invention provides a method and apparatus for preheating combustion (intake) air of an internal combustion engine during extreme cold ambient temperatures. A valve arrangement is provided to alter the flow of coolant through a radiator and aftercooler. During conditions where intake air temperature is below a predetermined temperature a fluid control valve causes coolant to first flow through a jacket water portion of the engine and next through the aftercooler where the intake air is preheated.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: March 25, 2003
    Assignee: Caterpillar Inc
    Inventor: Robert D. Roley