GB1174497A - Jet Flaps. - Google Patents

Abstract

1,174,497. Jet flaps on aerofoils. GIRAVIONS DORAND. 15 June, 1967 [20 June, 1966], No. 27653/67. Headings B7G and B7W. [Also in Division F2] A jet flap comprises a jet outlet at the trailing edge of an aerofoil 1, a rigid flap 4 hinged by a pivot (6), Fig. 1 (not shown), to the aerofoil aft of the jet outlet, a flexible member 2 forming a continuation of one wall of the jet outlet and attached to the trailing edge of the flap 4, and operating means, e.g. a rod 9, to pivot the flap 4 up and down, and thereby flex the member 2 to deflect the jet accordingly. The rigid flap 4 may have pivoted at its trailing edge a section 11 to which the member 2 is rigidly attached. To prevent flutter there may be a dome headed member 12 urged against the member 2 by a spring 15 when the member 2 is not deflected. As the member 2 is tensioned when deflected, the rigid flap 4 may comprise telescopic elements, Fig. 6 (not shown), which are sprung to tension the member 2 at all times. The pivot (6) may be carried on the aerofoil 1 by lugs (7), Fig. 1 (not shown), which form continuations of the aerofoil ribs. The member 2 and the rigid flap 4 may each be divided into elements spanwise, the links 9 being controlled in unison by a spanwise rod 19 via bell-cranks 18. The aerofoil may be an aeroplane wing or a blade of a helicopter lift rotor. If the aerofoil were a helicopter blade the flap would be moved cyclically, and the tendency of the flexed member 2 to return to its undeflected position may be, at least partially counteracted by the centrifugal force on masses 20 located on the bell-cranks.