Patent GB-560996-A (GB)
Title: Improvements in or connected with wings for aircraft
IPC: B64C9/20
Filed: 1942-11-03
Abstract: 560,996. Controlling aircraft. SHORT BROS. (ROCHESTER, & BEDFORD), Ltd.; and GOUGE, A. Nov. 3, 1942, Nos. 15441 and 18608. [Class 4] An aircraft wing is provided with primary and secondary ex tension flaps. in tandem which are adapted to be extended in sequence outwardly and down wardly so as to open slots at their leading edges at separate and successive stages, first one slot and then the other being opened by continued operation of the extending means. In one form, a primary flap B normally nested beneath the trailing edge of a wing A has a secondary flap C normally nested beneath the primary flap, both flaps being movable rearwardly and downwardly upon curved rails, not shown, mounted on the wing A and flap B respectively: The flap B is extended by a nut D traversed along a screwed shaft D until the position shown in Fig. 2 is reached, which is the position for take-off, after which, further movement of the nut releases a latching lever B<5> from engagement with one end of a lever B<1> pivoted in the flap B, the other end of which is connected by a link B<2> to a pin B<3> working in a slot A<1>. Continued movement of the nut D<1> immediately causes the pin B<3> to engage the end of the slot A<1> and the lever B<1> is turned to project the secondary flap C through a link B<4>, lever C<1> and link C<2>. The position with both flaps projected is used for landing. Reverse movement of the screwed shaft restores the parts to their initial position. Fig. 8 'shows another form in which the nut D<1> is connected primarily to the secondary flap C by a jointed link C<5>, C<2>. When the position shown is reached, the end of the link C<5>, which is forked, encounters an abutment on the flap B, and two rollers C<6>, Fig. 11, engage recesses in two half pinions B<8> mounted in the flap B and engaging short racks A<2> on the wing. Further movement of the nut D<1> then projects the flap B and the half pinions are rotated by the racks A<2> until they engage the opposite sides of the rollers C<6>, to which position they are biassed by a coiled spring, and further movement of the nut D<1> projects the flap B completely. Return movement of the nut returns the flap B to the position shown in which the rollers C<6> are released from the pinions B<8> by the action of the racks, whereupon the flap C can be retracted. Fig. 16 shows another form in which the nut D<1>, slidable in a groove B<6> in the flap B, is connected by a link C<2> to the flap C, both flaps being biassed to their retracted positions by springs E, E<1>, of which the spring E<1> is the stronger. Movement of the nut D<1> to project the flaps first moves the flaps B, C together until the flap B encounters a stop, after which the flap C is projected. In a modification, the spring E<1> is omitted and the flap C is projected until the nut D<1> encounters an abutment on the flap B which is then extended. In a further modification, the nut D<1> is similarly connected to the flap C and both springs are omitted. In this form the flap B is locked to the wing by a pivoted latch which is released by the nut D<1> just before the latter reaches the abutment on the flap. In the form shown in Fig. 4, a nut D<1> on the shaft D is connected by a link C<2> to the flap C and a second nut on the shaft is rotatable within a housing D<3> having trunnions working in guides B<7> in the flap B. Rotation of the shaft D extends the flap C until an extension on the nut D<1> releases a lock B<5> just before the nut engages an abutment D<2> on the flap B. The nut in the housing D<3> rotates freely during this stage of the extension. Further rotation of the shaft causes movement of the flap B and the end pressure of the housing D<3> against the enclosed nut arrests its rotation so that it advances in step with the nut D<1> and prevents the flap from overrunning the nut D<1>. The flaps may be further subdivided and arranged to open slots successively as the operating mechanism is actuated. Specifications 443,516, 470,923 and 510,774 are referred to.