US Patent 7207309 Runaway engine shutdown using compression inhibiting mechanism

An engine that is operating with a combustible intake mixture may begin in to runaway, or in other words, uncontrollably operate at excessive speeds. In order to shutdown a runaway engine, the present disclosure determines whether an engine is operating in a runaway condition. If the engine is operating in the runaway condition, a compression inhibiting mechanism is moved from a first position in which compression ignition can occur within at least one combustion chamber and a second position in which compression ignition cannot occur within the at least one combustion chamber.