Blade fold restraint system
AssigneeUnited Technologies Corporation
InventorDonald L. Ferris
Life of this patent
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Abstract
In a fully articulated helicopter rotor head, utilizing an elastomeric bearing to support each rotor blade and react centrifugal flight loads, a blade restraint, effective in three axes is provided for use during blade folding for aircraft stowage purposes. The restraint allows the blade to be folded through a predetermined fold plane, and held there while preventing or minimizing deflection of the elastomeric bearing.
Claims7
In a helicopter rotor wherein each blade is independently supported from a hub arm for full articulated flight motions by an elastomeric bearing establishing blade pitch, flapping, and lead/lag axes all intersecting at the focal point of the bearing, and having flight control linkage including a blade mounted pitch control horn, and further having a blade fold system including a substantially vertical blade fold hinge for each blade, located outboard of and independently of the elastomeric bearing;
- an improved three axis blade restraint mechanism for said fold system characterized by a lock assembly mounted on the hub arm and including a retractable pin adapted to engage the radial extremity of the pitch control horn, wherein the pin axis is offset from the blade pitch, flapping, and lead/lag axes and also intersects the focal point of the elastomeric bearing.
Dependencies are inferred from the claim text.