Accession Number : ADD006703

Title :   Three Actuator Steering System.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Bowdy,Fredrick E

Report Date : 30 Oct 1979

Pagination or Media Count : 5

Abstract : The invention concerns a three actuator steering mechanism for rotating a strut type forward landing gear of an aircraft particularly adapted for use in ground steering. The actuators are of a linear push-pull construction and are mounted at both ends by rotatable joints. At one end the joints attach the actuators to a nonrotating segment of the landing gear structure, while at the opposite ends the joints connect the actuators to a steering collar through which the landing gear is actually rotated. With the landing gear aligned in the forward direction, the two laterally mounted acuators form moment arms with the steering collar about the vertical rotational axis of the landing gear, in the conventional fashion. The center actuator is attached with an orientation such that it contributes no steering torque with the landing gear facing forward but increasingly supplements the two lateral actuators as the steering angle of the steering collar diverges in either direction from forward. The push-pull control of all three actuators is regulated by means of crossover valves responsive to the angular alignment of the rotatable steering collar. The torque output of the steering collar is the cumulative effect of the three actuators working in concert. When appropriately oriented, not only is the available steering torque symmetric about the forward direction but increases substantially as the steering angle rises, thereby providing the additional torque necessary to offset concurrent increases in demand created by effects such as tire scuffing, aircraft weight shifts and landing gear caster angle.

Descriptors :   *Patents, *Actuators, *Steering, *Landing gear, Aircraft, Inventions, Struts, Telescoping structures

Subject Categories : Aircraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE