| 摘要 |
<p>A helicopter has main rotor blades (22) foldable over its tail cone (12) and a tail rotor pylon (14) which is foldable about a tail cone vertical hinge (24) from its fore-and-aft flight position through an angle approaching 180 to lie alongside the tail cone. An arrangement to allow the tail rotor pitch controls to accomodate the folding of the tail rotor pylon comprises a tail rotor pitch control mechanism (26) including a cable (28) which extends across the foldable hinged members, direction change pulleys (30, 32, 34) for the cable and an improved 4- bar linkage system which controls the movement of the pulleys within a small envelope circle and maintains a constant tension on the cable throughout the full fold cycle. </p> |
