Landing gear mechanism including bypass valve assembly for reducing

Abstract

Landing gear mechanism includes a restrictor assembly containing a main orifice for controlling the rate of instroke of the landing gear mechanism during landing and a taxi instroke bypass valve which provides for increased flow of hydraulic fluid within the landing gear mechanism whenever the landing gear mechanism engages a bump during taxiing to reduce the damping loads that would otherwise occur if all of the hydraulic fluid were required to flow through the main orifice. The taxi instroke bypass valve assembly includes a slide member axially movable relative to the restrictor assembly for opening and closing one or more bypass orifices in the restrictor assembly. The slide member is held in the closed position whenever the landing gear mechanism is in a specified stroke range from fully extended by a secondary piston which is acted upon by the pressure in a precharged secondary chamber urging the secondary piston into engagement with a probe connected to the slide member. At some point in the strut stroke, the pressure within the upper piston chamber of the landing gear mechanism will rise to that of the precharged secondary chamber, whereby the secondary piston will be stroked along with the main strut piston and the slide member will move to the open position allowing fluid to bypass the main orifice, thereby reducing the damping loads as the landing gear mechanism negotiates bumps during taxiing.