Patent GB-129781-A (GB)
Title: Improvements in Control Devices for Aircraft.
IPC: B64C13/00
Filed: 1918-07-12
Abstract: 129,781. Boulton & Paul, and North, J. D. July 12, 1918. Steering and balancing. -An aeroplane control column, of the kind in which the elevator and ailerons are respectively operated by longitudinal swing- ing movements of the column and by turning movements of a handwheel at its upper end, is provided with means for disconnecting the hand-wheel from the aileron control and coupling it to the rudder control, the ailerons becoming automatically locked in the position they occupy at the moment; and the column also carries means for resiliently locking the rudder in any position. Fig. 1 shows one form of control column mounted on a shaft 2 which operates the elevators. Fixed to the column is a shaft 4, preferably with its axis intersecting that of the shaft 2, on which is mounted a rotary and sliding sleeve 10 having a sprocket-wheel 9 geared to a sprocket-wheel 7 on the hand-wheel shaft t 5. Loosely mounted on the shaft 4 is a drum 11 around which cords 13 from the rudder-bar are wound in opposite directions and are connected at their ends to springs 14, 15 which in turn are connected by rods 16 to a chain 17 passed around a sprocketwheel 18 secured to a sleeve 19 at the upper part of the column. A worm-wheel 22 secured to the sleeve 19 is geared to a worm on a shaft 24 having a hand-wheel 25 so that one or other of the springs 14, 15 'can be tensioned to hold the rudder in a set position. The slack of the relaxed cable is taken up by a light spring 26 arranged within each spring 14, 15. One end of the shaft 24 is supported in a bearing carried by a lever 27 provided with a spring catch 28, so that the worm can be quickly withdrawn from engagement with the worm-wheel. The aileron cables are connected to a drum 12 loosely mounted on the shaft 4 and having clutch teeth normally engaged by a clutch on the sleeve 10. Movement of a lever 31 slides the sleeve 10 out of engagement with the drum 12 and into engagement with the drum 11. At the same time, a clutch 34 keyed to the shaft 4 is pressed axially by a spring 35 into engagement the clutch teeth of the drum 11 and locks it to the shaft 4. Fig. 5 shows a modification in which the worm-wheel 22 and sprocket-wheel 18 are carried by a sleeve loosely mounted on an extension of the shaft 5, and the worm shaft 24 is mounted in a frame 37 pivoted at 38 and supported at its opposite edge by a collar on a spring-pressed lever 41 when the worm is in engagement with the wheel 22. The front and rear members 1, 1<x> of the column are .secured to a bracket mounted on two transverse tubes 46 which are connected by end brackets to co-axial shafts which operate the elevator. The drums 11, 12 are freely mounted on fixed sleeves 51, 50, and the sprocket-wheel 9 is mounted on a sleeve which can rotate, but not slide, on a sliding sleeve 52 extending through the sleeves 50, 51. Movement of the lever 31 moves the sleeve 52 and brings one or other of the clutch members 29, 30 on the sprocket-wheel sleeve into engagement with one of the adjacent drums 12, 11. As the drum 12 is disengaged from the sprocket-wheel, a bolt 53 simultaneously locks it against rotation, as shown.