# US 9,751,620 B2 · Aircraft having landing gear doors and a system for maneuvering the doors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,751,620 B2 - Document ID: US9751620B2 - Status: Granted - Kind: B2 - Application number: 14/847,255 - Filed: 2015-09-08 - Published: 2016-03-10 - Granted: 2017-09-05 - Earliest claimed: 2014-09-05 - Assignees: Airbus Operations GmbH - Applicants: Airbus Operations (S.A.S.) - Inventors: Christophe Casse; Didier Reynes - Web page: https://patentgrep.com/patent/US9751620B2 ## CPC - B64C 25/16: Fairings movable in conjunction with undercarriage elements - B64C 1/1407: {Doors; surrounding frames} - B64C: AEROPLANES; HELICOPTERS ## Abstract An aircraft with a landing gear, a compartment to stow the landing gear and doors for the compartment movable between an open position and a closed position. The movement of the doors is controlled by a maneuvering system having two transmission chains or linkages each connecting one of the doors to an actuation member that includes a rotatable arm and an actuating cylinder. Each transmission chain or linkage has a relay element mounted pivotably on a structural element of the aircraft, a first connection element between the arm and the relay element, and a second connection element between the door and the relay element. ## Claims ### Claim 1 An aircraft comprising a first door, a second door and a maneuvering system configured to move each door between an open position and a closed position, the maneuvering system comprising: an actuation member comprising an arm mounted pivotably on a first structural element of the aircraft and an actuating cylinder mounted on a second structural element of the aircraft, wherein the actuating cylinder is configured to move the arm; and transmission chains or linkages each connecting one of the doors to the actuation member, wherein each transmission chain or linkage comprises: a relay element mounted pivotably on the first structural element of the aircraft a first connection element between the arm and the relay element; and a second connection element between the respective door and the relay element. ### Claim 2 (depends on 1) The aircraft according to claim 1, wherein the actuating cylinder includes one of a pneumatic or hydraulic reservoir or electric motor, which extends and retracts the actuating cylinder to move the arm of the actuation member. ### Claim 3 (depends on 1) The aircraft according to claim 1, wherein the transmission chains or linkages are symmetrical about a longitudinal axis of the aircraft. ### Claim 4 (depends on 1) The aircraft according to claim 1, wherein the first and second doors are flush with a skin of the aircraft while in the closed position and are folded inside a compartment of the aircraft while in an open position. ### Claim 5 (depends on 1) The aircraft according to claim 1, wherein the first and second doors each pivot between the closed position and the open position. ### Claim 6 (depends on 1) The aircraft according to claim 1 wherein: the actuating cylinder is pivotably mounted to the second structural element of the aircraft, the arm and the actuating cylinder are connected by an articulated joint at a connection zone, and each first connection element is connected to the arm at the connection zone. ### Claim 7 (depends on 1) The aircraft according to claim 1, wherein the first structural element is a lower platform of the aircraft and the second structural element is an upper platform of the aircraft. ### Claim 8 (depends on 6) The aircraft according to claim 6 wherein: the arm has a first end mounted pivotably on the first structural element of the aircraft and the actuating cylinder has a first end mounted pivotably to the second structural element of the aircraft, and a second end of the arm is connected by the articulated joint to a second end of the actuating cylinder at the connection zone. ### Claim 9 (depends on 8) The aircraft according to claim 8, wherein the first end of the arm is splayed and the second end of the arm is narrow. ### Claim 10 (depends on 9) The aircraft according to claim 9 wherein: the arm includes non-parallel, longitudinal segments connected to one another by a transverse segment, and at the first end, the longitudinal segments are at a maximum spacing form each other, and at the second end, the longitudinal segments are at a minimal spacing from each other. ### Claim 11 (depends on 8) The aircraft according to claim 8, wherein the first end of the arm and the first end of the actuating cylinder are each mounted pivotably, respectively, on the first structural element and the second structural element of the aircraft about an axis of rotation that is parallel to a transverse axis of the aircraft, and in that the articulation of the connection zone is formed about an axis that is parallel to the transverse axis of the aircraft. ### Claim 12 (depends on 1) The aircraft according to claim 1, wherein the relay element is a rigid part, mounted pivotably about an axis that is parallel to a longitudinal axis of the aircraft, wherein the first connection element and the second connection element are each formed by a connecting rod. ### Claim 13 (depends on 1) The aircraft according to claim 1 wherein: each of the doors is connected to a supporting part which is mounted pivotably on the first structural element of the aircraft to allow the door to pivot between the open position and the closed position, and the second connection element connects the supporting part to the relay element. ### Claim 14 (depends on 1) The aircraft according to claim 1, wherein at least the first or the second connection element forms a force-limiting member for each transmission chain. ### Claim 15 (depends on 14) The aircraft according to claim 14, wherein the force-limiting member is a connecting rod. ### Claim 16 (depends on 15) The aircraft according to claim 15 wherein: the connecting rod either connects the relay element to the arm or connects the relay element to a supporting part, and the connecting rod comprises: a jacket, a rod that is positioned within the jacket, and a spring biasing the rod toward a bottom of the jacket, wherein the rod is displaced along an axis of the jacket to maneuver the doors. ### Claim 17 (depends on 1) The aircraft according to claim 1, wherein the first door and the second door close a compartment of the aircraft configured to stow main landing gears. ### Claim 18 (depends on 1) The aircraft according claim 1, wherein the first door and the second door are separated by a fixed panel of the aircraft, wherein the doors are disposed in continuity with the fixed panel when in the closed position. ### Claim 19 An aircraft comprising: a fuselage having an outer skin and a compartment; doors connected to the fuselage, wherein the doors have a closed position closing the compartment and contiguous with the outer skin and an open position at which the compartment is open through the outer skin; a door maneuvering system comprising: an arm pivotably mounted to a lower platform of the fuselage, wherein the arm pivots within a plane parallel to a longitudinal axis of the fuselage; an actuating cylinder mounted to an upper platform of the fuselage and having an extendible end region connected to the arm, wherein the actuating cylinder extends to pivot the arm; and a transmission chain or linkage for each door, wherein each transmission chain or linkage is connected to a respective one of the doors and to the arm, wherein each transmission chain or linkage comprises: a relay arm with one end mounted pivotably to the lower platform of the fuselage and an opposite end coupled to a middle section of the transmission linkage. ### Claim 20 (depends on 19) The aircraft of claim 19 wherein the transmission chain or linkage for each door is symmetrical with the other transmission chain or linkage about the longitudinal axis. ### Claim 21 (depends on 19) The aircraft of claim 19, wherein the relay arm is mounted pivotably about an axis that is parallel to a longitudinal axis of the aircraft.