Abstract: A door latching and lifting mechanism for use on an aircraft as an escape hatch. The door (10) is an upwardly opening plug-type door. Its latching mechanism (12) consists of a torque tube (80) and handle (90), both of which are carried by the door (10). Pulling on the handle (90) rotates the tube (80) and causes door latch pins (113) to retract, thus releasing the door (10). A preloaded lift spring (48), connected to the door (10) by an overhead cable (18), automatically pulls the door upwardly as soon as the pins (113) retract.

Abstract: A passenger door is connected to an aircraft fuselage by a hinge mechanism having an elongated goose-neck hinge member. One end of the hinge-member is pivotally connected to an idler crank arm that is pivotally connected to the fuselage. The other end of the goose-neck member is pivotally connected to the door. A guide arm connected to the door and carried by the idler crank arm controls door movement. An end of the guide arm has a pin that follows a groove in an "S"-shaped guide track. The shape of the track causes the guide arm to initially pivot and translate the door partially inwardly into the fuselage during opening movement, and then swing the door outwardly until it is parallel with the fuselage's outer surface.

Abstract: 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.

Abstract: A compact, cam operated, counterbalance system (30) is provided for the torque tube assembly (25) associated with a moveable hinged structural member (20) of the type hingedly connected to a fixed structural member and adapted to pivot about an inclined hinge axis in which the counterbalance system includes: (i) a cylindrical cam (31) surrounding a torque tube (38) and defining an axially presented continuous cylindrical cam surface (32) formed by a plurality of axially presented curved ramps (32a, 32b); (ii) cam follower means (34, 35, 36) mounted concentrically about the torque tube (38); (iii) a compression spring (42) mounted concentrically about the torque tube (38) for continuously biasing one of the cylindrical cam (31) or the cam follower means (34, 35, 36) axially towards the other; (iv) one of the cylindrical cam (31) and the cam follower means (34, 35, 36) being rigidly mounted on the fixed structural member (22); (v) the other of the cylindrical cam (31) and the cam follower means (34, 35, 36) bei