GB697014A - Improvements in or relating to gas turbine engine control systems - Google Patents

Abstract

697,014. Linkwork. ROLLS-ROYCE, Ltd. July 20, 1951 [July 26, 1950], No, 18736/50. Class 80 (iii). [Also in Groups XXVI and XXXIII] A gas turbine engine control system comprising a control lever connected by mechanical linkage to a control valve regulating the fuel supply and to the speed selecting device of a speed governor which controls the rotational speed of the engine by adjustment of the load has means, operated in accordance with the ambient atmospheric temperature, connected to said linkage to effect an additional adjustment of the control valve whilst causing substantially no adjustment of the speed selecting device. The pilot's control lever 12 is connected to the arm 10b of a rocking lever 10 through a link 11. A second arm 10c of the lever 10 is connected through linkage 27 to the actuating lever 14a of a datum speed selecting unit 14 of a constant speed airscrew unit and a third arm 10d is connected to the operating lever 15a of the throttle valve 15. The third arm 10d has at its end a boss 10e carrying a pivot pin 16 on which is mounted a cranked lever 17 comprising a pair of arms 17a, 17b which are at right angles to one another. The arm 17a is connected through a link 18 which extends through the boss 10a of the lever 10 to a mechanism 22. This mechanism, which may be electrically operated, has a lever 21 which may be forced to one end or the other of the slot 23 by operation of the switches 24, 25. When the control lever 12 is in the idling position shown the pivot pin 16 is in a position in which it is substantially parallel or makes only a small angle with the link 26 connected to the operating lever 15a of the throttle valve 15. In this position movements of link 18 will cause no substantial axial movement of the link 26 since the end of the arm 17b to which this link is connected moves along a line substantially at right angles to the link 26. When the control lever 12 is in the maximum speed position the pivot pin 16 is moved to a position, Fig. 4, in which it is substantially at right angles or a large angle with the link 26. In this position, movements of the link 18 will cause axial movement of the link 26 since the end of the arm 17b then moves along a line substantially parallel to the link 26. The movements of the link 18 have no effect on the rocking lever 10 and so will not alter the setting of the constant speed unit 14.