GB930781A - Improvements in and relating to thrust reversers for jet propelled aircraft - Google Patents

Abstract

930,781. Deflecting propulsive jets on aircraft. ENGLISH ELECTRIC CO. Ltd. Dec. 1, 1959 [Dec. 12, 1958], No. 40237/58. Class 4. In a thrust reverser for jet propelled aircraft which can alternatively be used as an air brake, each of two double doors arranged symmetrically about the horizontal plane of symmetry of the jet pipe rear fairing has forward parts and rear parts hinged to one another about an axis transverse of the said centre plane, said axes describing circular arcs about fixed pivot points arranged adjacent to and symmetrical of said plane, while the leading edges of the forward parts are pivotally guided on slide booms in straight or slightly curved longitudinal guide tracks, whereby the said double doors can be moved from a fully retracted position flush with the said rear fairing into an intermediate position forming an air brake, and into an end position forming a so-called W-type thrust reverser. the wedge of the W-profile being formed by the trailing edges of the rear parts of the double-doors contacting one another in said centre plane, and the edges at the free ends of the W-profile being spaced apart from the trailing edge of the said rear fairing. A pair of jet pipes are arranged side-by-side in a rear fuselage fairing 33 which terminates in a pair of opposed double folding doors 1, 2 and 1<SP>1</SP>, 2<SP>1</SP> which are arranged symmetrically about the normally horizontal plane containing the axes of the jet pipes. The mechanism, described in detail for the upper doors only, comprises a sliding boom 21 attached to the leading edge of door 1 and provided with rollers 19 to engage a trackway 121 along which it is moved by a jack 16, the boom being locked in its forward full-line position by a locking bolt 14. The doors 1 and 2 are connected by a transverse pivot 3 and the rear end of door 2 is connected to a fixed pivot 22. In operation the jacks 16 are extended to move the doors to the intermediate dotted-line position in which doors 1 project beyond the profile of fairing 33 to act as an air brake, doors 2 being positioned so that their rear edges 12 do not impede the flow of propulsive gases from the jet pipes. The air-braking effect may be supplemented by a flap 24, which may be perforated, fixed to the leading edge of each door 2 and normally housed within the outer profile of door 1. Further extension of jacks 6 moves the doors to the rearmost chain-dotted position in which the edges 12 abut and the doors wholly contain and deflect forwardly the propulsive gases.