Patents by Inventor Ernst Goran Estmar

Ernst Goran Estmar 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).

  • Valve unit for braking pressure control in wheeled vehicles
    Patent number: 3977734
    Abstract: A valve unit for controlling air flow and braking pressure in the brake cylinder of a pneumatic braking system. The valve unit has an inlet and an outlet valve assembly each of which are controlled by a solenoid valve, which is in turn controlled by an electronic braking control system. In the inlet valve assembly there is a valve diaphragm which on one side is biased by one pressure to close the valve unit, and which on the opposite side is biased by two pressures to open the valve unit. The ratio between the areas affected by the respective pressures is selected in such a way that the brake cylinder pressure is raised in essentially constant steps.
    Type: Grant
    Filed: April 17, 1975
    Date of Patent: August 31, 1976
    Assignee: Saab-Scania Aktiebolag
    Inventors: John Fritiof Ronnhult, Ernst Goran Estmar, Bjarne Louis Petersen