The Boeing Company

Allan W Opsahl

Alex Maraghe

Franklin K Barnes

James R Kasper

A locking device is provided for holding an aircraft door in an open position. The device includes a first member connected to the door which moves in correspondence with door opening and closing. A second member of the device is fixedly connected to aircraft structure that supports the door. A locking pin, connected to the first member, is engaged with a pin receiving opening in the second member when the door is fully open to hold the door in such position. The pin is movable axially by a manually operated lever to disengage the pin when it is desired to close the door.

Hold-open lock

A compact, spring actuated, counterbalance system (10) for relatively large, inwardly opening aircraft bulk cargo doors (11) and similar closures of the type adapted to be pivoted about a horizontal hinge axis (12) oriented along the upper edge of the door (11) which is of the type commonly shifted through angles on the order of about 50.degree. between fully closed and fully opened positions and employing: (i) an overhead conventional type compression spring assembly (15) including a housing (20), a spring actuator (21) movable axially through the housing (20), and an axially compressible spring assembly (19.sub.a -19.sub.d) bottomed at one end on the housing (20) and at its opposite end on the spring actuator (21); (ii) a bell crank assembly (16) having a bell crank (24) pivotally mounted on the overhead aircraft structural frame (18) and having a pair of angularly related crank arms (24.sub.a, 24.sub.b); (iii) a control link (25) pivotally connected at one end to one of the angularly related crank arms (24.sub.b) and pivotally connected at its opposite end to the aircraft door (11); and (iv), a cable (22) coupled at one end to the spring actuator (21) and extending axially through the spring assembly (19.sub.a -19.sub.d) and the spring housing (20) and having its opposite end connected to the other of the crank arms (24.sub.a).

Aircraft door counterbalance system

Counterbalanced hinge assembly

An inboard wing trailing edge flap of an aircraft has a flap carriage mechanism located within the fuselage or a fuselage/wing fairing structure, and the flap is attached to the carriage by a torque tube which penetrates the side of the fuselage. A slot is required in the fuselage through which the torque tube can travel as the flap is extended and retracted. The slot is covered when the flap is fully retracted, but when the flap is fully extended, airflow through the slot toward the upper surface of the flap causes the flap to lose lift. Therefore, airflow blocker doors are provided for closure of the slot when the flap is fully extended. The doors are held in a closed position by a pressure differential across the slot and by spring-loaded hinges; and the doors are adapted to be opened by engagement of a ramp cam member mounted to the flap torque tube, as the flap is retracted.

Flap torque tube slot seal

An outward-opening, plug-type cargo door for an aircraft is movable between a closed position and an open position in which the door is spaced from the cargo bay opening in a canopy orientation above and outboard of the cargo bay opening. The door hinges are directly driven by irreversible rotary actuators such that the weight of the door cannot back-drive the actuators. The door must be powered to the opened and closed positions thereby eliminating the necessity of a strut to prop the door open when cargo is being loaded and unloaded. The rotary actuators are mounted to the aircraft structure independently of the hinge mechanism's attachment to the aircraft structure so that the actuators can be removed and replaced if necessary without disturbing the hinge mechanism or door linkage. The hinge linkage has been simplified to provide fewer parts for the linkage. The door is manually unlatched from either the interior or exterior of the aircraft through a dual handle system. A spring-biased pawl assembly is mounted on the door and coacts with a latch crank to prevent movement of the handle to the latched position when the door is spaced from the cutout opening. The spring-biased pawl cooperates with a cam surface associated with the cutout opening to permit movement of the handle to the latched position once the door is in the cutout opening.

Powered outward-opening cargo door

A compact, spring operated, two-way counterbalance system is disclosed for the hinge assembly of an inwardly/outwardly moveable plug-type aircraft passenger door of the type adapted to pivot about an inwardly canted hinge axis whereby a first convolute clock-type spring member is wound during the final stages of downward door-closing movement to provide an outward biasing force for assisting on-board flight attendants in opening the door during that portion of door movement when it must move in an upward direction; and, a second convolute clock-type spring member is provided which is wound during the latter stages of door opening movement when the door is moving in a downward direction, with the second convolute spring member thus providing a biasing force for assisting the on-board flight attendant in pulling the door upwardly and away from the fuselage during upslope door-closing movement. In the exemplary form of the invention disclosed, this is achieved by providing a pair of compact, coaxial, convolute, clock-type spring members which are oppositely wound and which have their free outer ends secured to the fuselage body structure with the inner ends thereof being separably engageable with radially projecting shoulder defining means formed on the inwardly canted body-mounted torque tube. The compact nature of the spring biasing arrangement of the present invention readily permits the incorporation of more extensive bearing support surfaces for the torque tube and the necessary snubber mechanisms and the like which serve to brake or retard movement of the relatively heavy door during the downward portions of movement when the door is being closed or opened.

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Renton, WA, United States of America

Allan W Opsahl