Hinge assembly for an aircraft door
A hinge assembly for connecting a door to a fuselage of an aircraft includes a hinge arm having a fuselage fitting pivotably coupled to a fuselage rotatable interface and a door fitting pivotably coupled to a door rotatable interface. The hinge assembly includes a programmable gear assembly coupled to the hinge arm allowing the hinge arm to pivot around the fuselage fitting when the door is moved from a door closed position to a door open position and causing the door to maintain in a generally parallel orientation relative to the fuselage between the door closed position to the door open position. The programmable gear assembly includes a fuselage gear coupled to the fuselage fitting, a door gear coupled to the door fitting, and a rack operably coupled between the fuselage gear and the door gear.
1. A hinge assembly for connecting a door to a fuselage of an aircraft, the hinge assembly comprising:
a hinge arm having a fuselage fitting at a first end and a door fitting at a second end, the fuselage fitting configured to pivotably couple to a fuselage rotatable interface mounted to the fuselage adjacent a door opening of the aircraft, the door fitting configured to pivotably couple to a door rotatable interface of the door; and
a programmable gear assembly coupled to the hinge arm, the programmable gear assembly configured to allow the hinge arm to pivot around the fuselage fitting when the door is moved from a door closed position to a door open position, the programmable gear assembly further configured to cause the door to move along a programed path relative to the fuselage as the door moves from the door closed position to the door open position;
wherein the programmable gear assembly includes a fuselage gear coupled to the fuselage fitting, a door gear coupled to the door fitting, and a rack operably coupled between the fuselage gear and the door gear, the programmable gear assembly including a first gear set at the first end, the first gear set including the fuselage gear, a rack drive gear, and at least one intermediary gear between the fuselage gear and the rack drive gear, wherein at least one intermediary gear transfers relative rotational motion of the fuselage gear to the rack drive gear, the rack drive gear engaging the rack to move the rack between a retracted position and an advanced position, the rack rotating the door gear as the rack moves between the retracted position and the advanced position.
2. The hinge assembly of claim 1 , wherein the hinge arm is configured so that when the door is moved from the door closed position to the door open position the hinge arm is pivoted through the door opening and the door is laterally offset from the door opening.
3. The hinge assembly of claim 1 , further comprising an emergency power assist assembly attached between the programmable gear assembly and the hinge arm so as to drive the door open in an emergency, and to limit the speed of the motion of the hinge arm when the hinge arm is moved between the door closed position to the door open position.
4. The hinge assembly of claim 1 , wherein the fuselage gear is adjustable relative to the rack and the door gear for tensioning the programmable gear assembly.
5. The hinge assembly of claim 1 , wherein the hinge arm includes a main body and an extension extending from the main body at a corner, the fuselage fitting provided at a distal end of the extension, the door fitting provided at a distal end of the main body.
6. The hinge assembly of claim 5 , wherein the rack extends along the main body to the door gear at the distal end of the main body.
7. The hinge assembly of claim 1 , wherein the programmable gear assembly is contained within a footprint of the hinge arm.
8. The hinge assembly of claim 1 , wherein the rack is directly coupled to the door gear to rotate the door gear as the rack moves between the retracted position and the advanced position.
9. The hinge assembly of claim 1 , wherein the first gear set extends along a curved gear path.
10. The hinge assembly of claim 1 , wherein the fuselage gear and the rack drive gear have a common diameter.
11. The hinge assembly of claim 10 , wherein the door gear has a common diameter as the fuselage gear and the rack drive gear.
12. The hinge assembly of claim 1 , wherein the programmable gear assembly includes an upper gear train, a lower gear train, and a shaft between the upper gear train and the lower gear train, the shaft located at the second end of the hinge arm, the rack is an upper rack, the fuselage gear is an upper fuselage gear, and the door gear is an upper door gear, wherein the upper fuselage gear, the upper door gear, and the upper rack form portions of the upper gear train, the lower gear train including a lower fuselage gear coupled to the fuselage fitting, a lower door gear coupled to the door fitting, and a lower rack operably coupled between the lower fuselage gear and the lower door gear, wherein the upper door gear is connected to the lower door gear by the shaft.
13. The hinge assembly of claim 12 , wherein the upper gear train is identical to the lower gear train.
14. The hinge assembly of claim 12 , wherein the upper gear train is coupled to an upper portion of the hinge arm, the lower gear train coupled to a lower portion of the hinge arm and extending parallel to and spaced apart from the upper gear train.
15. The hinge assembly of claim 12 , the lower gear train further comprising a lower rack drive gear and at least one lower intermediary gear between the lower fuselage gear and the lower rack drive gear, the lower rack drive gear engaging the lower rack to move the lower rack between a retracted position and an advanced position, at least one lower intermediary gear transferring relative rotational motion of the lower fuselage gear to the lower rack drive gear.
16. The hinge assembly of claim 12 , wherein the upper fuselage gear is adjustable relative to the upper rack and the upper door gear and the lower fuselage gear is adjustable relative to the lower rack and the lower door gear for to remove gear lash in the programmable gear assembly.
17. The hinge assembly of claim 1 , wherein the programmable gear assembly is configured to cause the door to maintain in a generally parallel orientation relative to a longitudinal axis of the fuselage as the door moves along the programed path between the door closed position and the door open position.
18. A hinge assembly for connecting a door to a fuselage of an aircraft, the hinge assembly comprising:
a hinge arm having a fuselage fitting at a first end and a door fitting at a second end, the fuselage fitting configured to be pivotably couple to a fuselage rotatable interface mounted to the fuselage adjacent a door opening of the aircraft, the door fitting configured to pivotably couple to a door rotatable interface of the door; and
a programmable gear assembly coupled to the hinge arm, the programmable gear assembly configured to allow the hinge arm to pivot around the fuselage fitting when the door is moved from a door closed position to a door open position, the programmable gear assembly further configured to cause the door to move along a programed path relative to the fuselage as the door moves from the door closed position to the door open position;
wherein the programmable gear assembly includes a fuselage gear coupled to the fuselage fitting, a door gear coupled to the door fitting, and a rack operably coupled between the fuselage gear and the door gear, the programmable gear assembly including a first gear set at the first end, the first gear set including the fuselage gear, a rack drive gear, and at least one intermediary gear between the fuselage gear and the rack drive gear, wherein at least one intermediary gear transfers relative rotational motion of the fuselage gear to the rack drive gear, the rack drive gear engaging the rack to move the rack between a retracted position and an advanced position, the rack rotating the door gear as the rack moves between the retracted position and the advanced position; and
wherein the fuselage gear is adjustable relative to the rack and the door gear for tensioning the programmable gear assembly.
19. The hinge assembly of claim 18 , wherein the programmable gear assembly includes a fuselage rack coupled to a fuselage rotatable interface at the fuselage, the fuselage gear coupled to the fuselage rack, the fuselage rack being adjustable relative to the fuselage rotatable interface to adjust the position of the fuselage gear to tension the programmable gear assembly.
20. A hinge assembly for connecting a door to a fuselage of an aircraft, the hinge assembly comprising:
a hinge arm having a fuselage fitting at a first end and a door fitting at a second end, the fuselage fitting configured to be pivotably couple to a fuselage rotatable interface mounted to the fuselage adjacent a door opening of the aircraft, the door fitting configured to pivotably couple to a door rotatable interface of the door;
a programmable gear assembly coupled to the hinge arm, the programmable gear assembly configured to allow the hinge arm to pivot around the fuselage fitting when the door is moved from a door closed position to a door open position, the programmable gear assembly further configured to cause the door to move along a programed path relative to the fuselage as the door moves from the door closed position to the door open position, wherein the programmable gear assembly includes a fuselage gear coupled to the fuselage fitting, a door gear coupled to the door fitting, and a rack operably coupled between the fuselage gear and the door gear, the programmable gear assembly including a first gear set at the first end, the first gear set including the fuselage gear, a rack drive gear, and at least one intermediary gear between the fuselage gear and the rack drive gear, wherein at least one intermediary gear transfers relative rotational motion of the fuselage gear to the rack drive gear, the rack drive gear engaging the rack to move the rack between a retracted position and an advanced position, the rack rotating the door gear as the rack moves between the retracted position and the advanced position; and
an emergency power assist assembly attached between the programmable gear assembly and the hinge arm so as to drive the door open in an emergency, and to limit speed of the motion of the hinge arm when the hinge arm is moved between the door closed position to the door open position.
21. The hinge assembly of claim 20 , wherein the emergency power assist assembly includes an actuator and a piston operably coupled to the actuator, the piston includes a drive rack and a drive gear rotated by the drive rack, the drive gear being coupled to the hinge arm, the actuator being operated to rotate the hinge arm to open the door.