GB865881A - Means for actuating a variable area jet propulsion nozzle - Google Patents

Abstract

865,881. Jet propulsion nozzle. CANADA, MINISTER OF NATIONAL DEFENCE OF. Dec. 7, 1959, No. 41480/59. Class 110 (3). A variable-area jet-propulsion nozzle having a series of annularly arranged longitudinally extending flaps pivotally mounted at their one ends to supporting structure to define a duct terminating in a discharge orifice, has cam members with profiled cam surfaces, which cooperate with abutments mounted on fixed structure surrounding the duct, pivoted on the exterior of the flaps adjacent the free ends thereof and means to pivot the cam members in synchronism to move the cam surfaces relative to the abutments to cause pivoting of the flaps. The tail pipe 14 terminates in a peripheral groove 18 in which are pivotally mounted flaps 19. Sealing members 22 comprising a pair of flanges 23, 24 spaced apart by a web 25 are located between each pair of flaps 19. The sealing members 22 are attached to the flap by rivets 30 which pass through holes 27 and slots 28. Each flap has a pair of trunnions 31 pivotally supporting a cam member 32 having a profiled cam surface 33. The inner skin 15 of the nacelle has a plurality of pairs of trunnions each pair of which support a roller 35 which engages the cam surface 33 when propulsive gases flow through the nozzle. When it is desired to lessen the area of the discharge orifice the ring 39 is moved rearwardly by the ram 51 so that cam members 32 pivot about the axles 34 and the surfaces 33 ride along the rollers 35. This causes the flaps 19 to reduce the area of the orifice. The inturned ends 37 of the trunnions 34a prevent the flaps falling inwards when the engine is not in operation. In a modification the cam surfaces face upstream and not downstream as shown.