| 摘要 |
<p>A suspension damper (10) particularly for use in a helicopter undercarriage comprises a hollow piston (11) having a piston head axially slidable in a cylinder (12) filled with hydraulic fluid, a compression fluid passageway (19) in the piston head through which hydraulic fluid is metered during compression of the damper, and an extension fluid passageway (21) through which hydraulic fluid flows during extension of the damper. A selectively operable valve means (23) is adapted to close the extension fluid passageway (21) to prevent extension of the damper whilst permitting further extension thereof. When used on a helicopter undercarriage, the damper of this invention reduces or eliminates instability of the helicopter when at rest on an unstable platform.</p> |
