GB667911A - Improvements in aircraft - Google Patents

Abstract

667,911. Aircraft control surfaces. BLACKBURN & GENERAL AIRCRAFT, Ltd. May 1, 1950, No.10721/50. Class 4. A high speed aircraft with variable sweepback wings has movable wing tips 8 and ailerons 9 for lateral control, the former being operable only when the wings are in their high-speed swept-back position and the latter only when the wings are in the low-speed out-spread position. Each wing tip 8 is rotatable about a shaft 10 and is actuated by links 11, 12 and a bell crank 13, while each aileron 9 is operated by links 14, 15 and a bell crank 16. The ends of the free arms of the bell cranks are connected bv a slotted link 17, one end of which is connected by a link 18 to a pilot-operated member 20. When the control surfaces are operated the link 17 pivots about its point of connection with a link 21, connected by a further link 22 and bell crank 23 to one end of a rod 24 whose other end is pivotally attached to the fuselage at a point 25 which is offset relatively to the wing pivot 4. In the lowspeed position, Figs. 1 and 4, the fulcrum of link 17 is disposed above the end of the free arm of bell crank 13, whereby movement of the control member 20 results in rotation of bell crank 16, to actuate the aileron 9. Displacement of the wing into the swept-back position causes movement of members 23, 22, 21 whereby the fulcrum of link 17 is moved into a position above the end of the free arm of bell crank 16 (Fig. 5), so that control member 20 actuates the bell crank 13 and the wing tip 8. If either surface is in operation when the wing is moved, control is transferred progressively to the other surface,