GB882424A - Improvements in or relating to aircraft jet propulsion apparatus - Google Patents

Abstract

882,424. Defelcting aircraft propulsion jets. ROLLS-ROYCE Ltd. March 16, 1959 [April 3, 1958], No. 10935/58. Class 4. A vaned structure for jet-propulsion apparatus comprising a jet pipe and nozzle and a duct housing the vaned structure for assisting in imparting to the gas flow a reversed component of velocity, comprises first and second vane means for assisting in imparting to the gas components of velocity in first and second directions respectively, so that the reversed thrust jet issuing from the structure has components ofvelocity at right angles to one another and to the direction of gas flow in to the structure. Fig. 2 is a view of the structure looking radially towards the jet pipe, and Fig. 3 a view seen from the direction of arrow 3 in Fig. 2. The second vane means comprises curved strips 26, 27, supporting cascades of curved vanes 25 constituting the first vane means. Certain strips 27 are relatively rigid, and the vanes on opposite sides of such strips are aligned, e.g. strips 27a and vanes 25a, 25b. On each side of each strip 27 are relatively flexible strips 26, and the vanes on opposite sides of such strips are staggered e.g. strip 26a and vanes 25c, 25d. Thermal expansion of the vanes can thus be taken up by sinusoidal deformation of the flexible strips 26. The outer ends of vanes 25a, 25c, are connected to thin sheet metal walls 28. Two such structures are diametrically oppositely disposed about the jet pipe each in a short duet leading from a port in the jet pipe to an aperture in the nacelle housing the jet propulsion plant. Eyelids in the jet pipe normally blank off the ducts so that the gas flows to the nozzle, but, for reverse thrust, can blank off the nozzle and divert the gas to the ducts and vaned structures, Fig. 1 (not shown). The laterally deflected gas is given a downward as well as a forward component of velocity by the vanes, so that the deflected gases from two side by side engines do not mutually interfere. The vaned structure is supported in the duct in the following way. The relatively rigid strips 27 are provided at their forward ends with flanged portions 30 bolted to facings 31 on the forward wall of the duct, and at their other ends with plug members 33 slidable in sockets 34 on the rear wall of the duct. The walls 28 are provided at their forward ends with bushes 37 aligned with sleeves 38 mounted on the duct walls, and locating members 38a in the sleeves 38 are pivotally and slidably engaged with the bushes 37.