Patent ID: 6792844
Filing Date: 2004-09-21
Classification: B64C,F15B

Abstract:
A hydraulic system for raising and lowering aircraft landing gear, the system including an actuator which is extendible and retractable to operate the landing gear, the actuator including a movable member in a casing, the movable member being moved relative to the casing in a first direction to extend the actuator when fluid under pressure is supplied to a first side of the movable member while fluid is exhausted from a second side of the movable member, and the movable member being moved in a second direction to retract the actuator when fluid under pressure is supplied to the second side of the movable member while fluid is exhausted from the first side of the movable member, and there being a selector valve selectively to supply pressurized fluid to the first or second side of the movable member, and wherein a valve is provided to permit exhausted fluid from at least one of the first and second sides of the movable member to augment the supplied fluid from the selector valve and thus be directed with the supplied fluid, to the second or first side respectively of the movable member; andwherein a relief device is provided to relieve exhausted fluid which is not recirculated from the at least one of the first and second sides of the movable member as the movable member reaches the end of travel in the casing.