Turbojet engine thrust reverser with variable exhaust cross-section

A thrust reverser for a turbofan-type turbojet engine having a hot gas exhaust duct comprising:

• (a) a stationary cowl arranged generally concentrically about the hot gas exhaust duct so as to define a generally annular cold flow air duct therebetween;
• (b) deflection vanes attached to the stationary cowl;
• (c) a first movable cowl slidably attached to the stationary cowl so as to be movable in a generally axial direction;
• (d) a second movable cowl slidably attached to the stationary cowl so as to be movable in a generally axial direction;
• (e) actuating means operatively interposed between the stationary cowl and the second movable cowl to move the first and second movable cowls with respect to the stationary cowl between:
• a first position wherein the first movable cowl is axially adjacent to the stationary cowl and the second movable cowl is axially adjacent to the first movable cowl to provide aerodynamically smooth exterior and interior surfaces;
• a second position wherein the first and second movable cowls are displaced axially as a unit away from the stationary cowl to thereby uncover the deflection vanes;
• and a third position wherein the second movable cowl is axially displaced from the first movable cowl which is axially adjacent to the stationary cowl to increase the exit area of the cold flow air duct;
• (f) flap means pivotally attached to the first movable cowl so as to be movable between a retracted position wherein the cold flow air duct is open and the flap means covers the deflection vanes to prevent air flow therethrough, and a blocking position wherein the deflection vanes are uncovered and the cold flow air duct is blocked to direct cold flow air through the deflection vanes;
• and,
• (g) flap activating means operatively connected to the flap means such that the flap means are moved from the retracted position to the blocking position only when the first movable cowl is displaced away from the stationary cowl.