Cargo door handle
A flush door latch assembly used to secure a hinged aircraft access door. The assembly comprises a spring-loaded exterior handle, an actuator, an interior handle, and housing pan. During operation, the handles alternatively engage the actuator. When the exterior handle is in the retracted position, it disengages from the actuator. When the exterior handle is in the extended position, the interior handle is disengaged from the actuator. When the exterior handle is in the retracted position, it is stowed in the housing pan.
1. A flush door latch assembly for opening and closing an aircraft access door, said door having an exterior side and an interior side, and said door is adapted to have a rotatable interior handle and a rotatable exterior handle, said latch assembly comprising:
an actuator comprising an outer shaft, the outer shaft having an axis of rotation and fixedly connected to a rotatable interior handle, the actuator further comprising a cam follower adapted for controlling the door latch assembly in order to open and close the aircraft access door via a roller cam and track mechanism;
a rotatable exterior handle, fixedly connected to an inner shaft coaxially disposed within the outer shaft of the actuator the inner shaft having a cam follower pin and an extended position and a retracted position, the inner shaft being maintained in the retracted position by a spring; and
a housing pan, disposed around the rotatable exterior handle and fixedly mounted to the aircraft access door, and having a recess to receive and stow the rotatable exterior handle flush with the exterior side of the access door when the inner shaft is in the retracted position; and
an intermediate shaft fixedly connected to the housing pan and coaxially disposed between the outer and inner shafts, the intermediate shaft having a slot to form a cam lobe profile engaged with the cam follower pin as the inner shaft transitions between the retracted position and the extended position, the cam follower pin being guided by the cam lobe profile as the inner shaft is rotated while in the extended position to engage the cam follower in order to open and close the aircraft access door.
2. The flush door latch assembly according to claim 1 wherein the cam lobe profile provides a straight portion parallel to the access of the intermediate shaft to prevent rotation of the actuator when the external handle is moving to its extended position.
3. The flush door latch assembly according to claim 1 wherein the cam lobe profile is shaped to controllably rotate the inner shaft in response to the travel of the cam follower pin along the cam lobe profile during actuation of the door latch assembly.
4. The flush door latch assembly according to claim 1 wherein the housing pan includes a deepened recess portion disposed below the exterior handle to provide operator access thereto.
5. The flush door latch assembly according to claim 1 wherein the exterior handle automatically retracts into the housing pan if released when the exterior handle is in the extended position.
6. The flush door latch assembly according to claim 4 further including an aerodynamic flapper disposed over the deepened recess portion of the housing pan.