US Patent 7624567 Convergent divergent nozzle with interlocking divergent flaps

A nozzle system includes a multitude of circumferentially distributed convergent flaps, divergent flaps and inter-flap seals which circumscribe an engine centerline and define the radial outer boundary of an exhaust gas path. Each divergent flap includes longitudinal sides having a set of extension which are located at different longitudinal stations such that the extensions on adjacent divergent flaps interfit when the nozzle is in a minimum dilated position yet provide support for the intermediate flap seal when the nozzle is in a maximum dilated position to thereby provide a relative increase in the nozzle area ratio range.