Patent ID: 7735466

Claim:
A method of controlling exhaust pressure in an engine with an exhaust brake having a butterfly gate with a bypass opening provided in an outer edge of the butterfly gate and a slide-able piston having a lower end adapted to selectively block said bypass opening and having an upper end adapted to receive static exhaust gas pressure, said method comprising the steps of: closing the butterfly gate; blocking the bypass opening in the butterfly gate with the lower end of the piston as a result of closing the butterfly gate; generating static exhaust gas pressure in the exhaust brake responsive to closing the butterfly gate and blocking the bypass opening; applying the static exhaust gas pressure to the upper end of the piston; and unblocking the bypass opening in the butterfly gate by sliding the lower end of the piston out of at least a portion of the bypass opening responsive to the application of the static exhaust gas pressure to the upper end of the piston.