GB1345337A - Gas turbine engine having a thrust reverser - Google Patents

Abstract

1345337 Gas turbine engines having thrust reversers DEFENCE SECRETARY OF STATE FOR 28 Oct 1971 [20 Oct 1970] 49662/70 Heading B7G [Also in Division F2] A gas turbine engine, Fig. 3, has; a gas flow duct between a gas generator casing 10 and a fan cowl wall 18; a plurality of peripherally spaced blocker doors 24 which when inoperative (solid lines) block respective apertures in the wall 18 and which are each pivoted at the centre to a link 54 pivotally mounted to rigid structure upstream of the apertures and are each movably mounted at the downstream end to a mounting means, Figs. 5, 8, including a cam track 40 which the end of the door follows; and blocker door actuating means, Figs. 5, 8, whereby on actuation of the actuating means the shape of the cam track 40 causes the doors to move into or block the gas flow through the duct 14 (chain lines) so that the resultant of the force of the gas flowing through the duct 14 and the reaction force of the door mounting means tends to cause the doors to move to the inoperative position until the engine resultant thrust is zero when the direction of the resultant force reverses. The actuation means, Figs. 5, 8, is mounted in and extended downstream from a strut 26 between a pair of adjacent blocker doors 24 and comprises a ball screw 46, driven by a flexible drive 62, on which moves a yoke 48 having on each side a pin 50 or 52 forming part of a chain 30 adjacent a respective door, the chain 30 being supported by four double sprocket wheels 32 to 35. A lug mounted pin 36 of a door extends through the cam track 40, forms part of the chain 30, and, for part of its travel, is guided by a further cam track 42 of the same shape as the cam track 40. So that the chain follows the curve of the cam tracks 40, 42, further pins 44 of the chain 30 extend into the tracks. Movement of the yoke 48 causes movement of the chain 30 which causes the required movement of the door by virtue of the shape of the cam tracks 40, 42. The chassis may be alternatively driven by gears 72, 74 driving sprocket wheel 32.