GB541588A - Improvements in control limiting devices on aircraft - Google Patents

Abstract

541,588. Controlling aircraft. ROUANET, R. L. M. F., and REY, F. V. A. J. Feb. 21, 1940, No. 3300. Convention date, Feb. 22, 1939. [Class 4] The overloads on an aeroplane exceeding a given value brought about by gusts of wind &c. are automatically corrected or limited for aircraft of the type comprising pivoted wings 1 held in equilibrium by elastic connections 4, by correcting or limiting the movement of the control surfaces or their operaring mechanism, such as the control stick 20, by means of a mechanical connection between these parts and the wings operated by the rotation of the latter. In the form shown under such conditions for an upward overload, the movement of the control stick is corrected or limited for the elevator control by a stop 18 on an arm 17 rigidly secured to a rotatable sleeve 12, the sleeve being rotated in the direction of the arrow f<SP>1</SP> by the pressure of the wing extension 3 on one end of a bell-crank lever 7, 8 which is interconnected to the sleeve by a link 10 and a crank-arm 11 keyed thereto. In the inoperative position, the stop is held away by a spring 19, the end 7 of the bellcrank lever being applied against a stop 8a. The action of the stop may be greater or less than that which can be effected by the pilot; in the latter case the stop merely forms a warning and may in addition be combined with a warning signal. The stop 18 is sufficiently wide to enable it to contact with the control-stick whatever the position of the latter may be due to its rotation about a longitudinal axis 23 for effecting lateral control. In a modification, excessive overloads in the downward direction may also be allowed for by replacing the bell-crank lever by a pair of linked pivoted levers, one above and one below the wing extension 3, and forming the stop 18 as a square ring encircling the control stick; the movement of the latter can then be corrected or limited in either its fore or aft position according as the overload is downward or upward.