Landing gear mechanism including controlled instroke and rebound damping and stroke overload protection

A landing gear mechanism comprising a main cylinder, a main strut piston axially movable within said main cylinder, restrictor means contained within said cylinder and defining with said cylinder and piston upper and lower chambers, said restrictor means including orifice means providing for the passage of fluid between said upper and lower chambers during relative movement between said piston and cylinder, said orifice means comprising an opening through said restrictor means, and a metering pin attached to said piston for movement therewith, said metering pin extending through said opening in said restrictor means, and relief valve means contained within said metering pin for movement therewith, said relief valve means including means providing for the bypass flow of fluid from said lower chamber to said upper chamber via said relief valve means in response to a pre-set pressure drop from said lower chamber to said upper chamber only during an intermediate portion of the instroke of said landing gear mechanism, and means for blocking bypass flow of fluid from said upper chamber to said lower chamber via said relief valve means during the entire outstroke of said landing gear mechanism.