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Month in the Patent Office

Aircraft Engineering and Aerospace Technology

ISSN: 0002-2667

Article publication date: 1 September 1939



In an aircraft having a slotted wing, the slot of which may be obstructed by a flap, differentially‐operable mechanism is provided whereby the shutter is positioned to substantially fully open the slot when the wing flap is moved from its high speed position to a slight extent only. In one form, the flap 35, which is adapted to close normally the slot between an aircraft wing 30 and wing flap 31, is actuated through cables 52, pulley 53, lever 101, links 102, lever 103, shaft 104, lever 107, link 109, and a horn 108 mounted on the flap. The flap 31 is actuated through a link 105 connected to the lever 103. During initial movement, the link 109 approaches the lever 107, the pivot 111 approaching the shaft 104 to substantially nest the flap 35 against the rear edge of the wings. The arms to which the flap 31 is pivoted are provided with stops. The pulley 53 may be operated from a handwheel, through irreversible worm‐gearing, by an electric motor or by a hydraulic jack. In a modification, the flap 31, Fig. 3, is adjusted, on rotation of a crank 103, through a link 105. A pulley 54 is adjusted concurrently with the pulley 53 and, through a cam‐slot 121, follower 124 carried by a lever 122 pivoted to the wing, a link 126, a lever 128, a shaft 130, a lever 129 and a link 127, actuates the flap 35. The angle through which the flap 31 moves before the flap 35 is nested may be determined by adjusting the relative sizes of the pulleys 53, 54. In a further modification, the cam‐slot and follower are replaced by crank connected by a link to the lever 122. In this latter case the pulleys 53, 54 may be connected by a crossed belt or chain and a hydraulic jack pivoted at one end to the wing may actuate a crank on the shaft which carries the pulley 53. In a still further modification, the flap 31, Fig. 14, is adjusted on rotation of a pulley 151 through an arm 153, an arm 154 pivoted to a shaft 156, an arm 157 and a link 105. The flap 35 is adjusted, simultaneously with initial operating movement through pulley 158, arm 107, a link 109, a lever 160, a link 127 and a horn 108. An adjustable buffer 159 on the link 109 ensures closing of the flap 35 when the flap 31 is moved to its normal position.


(1939), "Month in the Patent Office", Aircraft Engineering and Aerospace Technology, Vol. 11 No. 9, pp. 371-372.




Copyright © 1939, MCB UP Limited

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