Patent ID: 7874160

Claim:
A mechanism included in a convergent-divergent nozzle connected to an aft portion of a gas turbine engine, the mechanism comprising: a convergent flap configured to be kinematically connected to the aft portion of the gas turbine engine; a divergent flap pivotally and directly connected to the convergent flap at a hinged connection; at least one actuator configured to be connected to the aft portion of the gas turbine engine and to mechanically prescribe the position of the convergent flap and the divergent flap by moving through one or more positions; and at least one biasing apparatus configured to position the divergent flap independent of the one or more positions of the actuator by substantially balancing a force on the divergent flap produced by a gas pressure on the nozzle, the at least one biasing apparatus comprising: a biasing linkage directly connected to the divergent flap through a pivotal and sliding connection, the biasing linkage configured to kinematically connect the divergent flap to the aft portion of the gas turbine; and a spring is directly connected to the divergent flap at a first end and is connected to the biasing linkage at a second end.