GB919153A - Improvements in or relating to aircraft control systems - Google Patents

Abstract

919,153. Controlling aircraft. WESTLAND AIRCRAFT Ltd. Oct. 8, 1960, No. 34555/60. Class 4. A rudder pedal control system has two pedals 1, each pivotally connected to a link 45 joining the ends of substantially parallel arms 2, 25 connected to a torque arm 3 (or 4) which operate a rudder mechanism via means 5, 8 interconnecting the two torque arms 3, 4, the position of each pedal being adjustable relative to its torque arm by changing the geometry of a parallelogram linkage 2, 3 (or 4), 25, and 45. The arms 3, 4 are attached to crown wheels 6, 7, respectively, Fig. 1, and a main control lever 11 is carried by a sleeve 9 connecting wheel 7 and arm 4, Fig. 2, a pinion wheel 17 fast with a sleeve 16 attached to a torsion bar 18, controlling a feel and trim mechanism via a cam, Figs. 4, 5 (not shown); a load can be imposed on torsion rod 18 to change the trim of the system. Adjustment of pedals 1 is obtained by moving a member 28, Fig. 2, to free balls 29 from a grooved plunger 32. The pedals are then depressed to move a piston 43, Fig. 3, against spring 41 to rotate a sleeve 44, via an external helix, which through pinion 36 moves a rack 31, 33, 34 and a plunger 32 to a new position where it is locked by return movement of member 28. Spring 41 is employed to raise the pedals to a new position. A brake master cylinder 26, Fig. 3, is operated by pressure on the top of pedals 1. Depression of one pedal transmits movement via arms 2, 3 (or 4) and gears 5, 8 to rotate tube 16 and adjust the artificial feel and trim mechanism, the racks 33, 34 rotating in opposite direction as permitted by bearings 39.