Aircraft landing gear assembly

Patent metadata

Field	Value
Publication number	US-9878780-B2
Application number	US-201615072974-A
Country	US
Kind code	B2
Filing date	Mar 17, 2016
Priority date	Mar 20, 2015
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

An aircraft landing gear assembly includes a bi-stable, split line tube biased to assume a tubular condition to serve in place of a lock link or side stay and an actuator configured to radially enlarge the tube at a region for folding.

First claim

The invention claimed is:

1. An aircraft landing gear assembly comprising:
a main shock absorbing strut arranged to be movably coupled to an aircraft so as to movable between a deployed condition, for take-off and landing, and a stowed condition for flight;
a support linkage coupled at a first anchor point to the main shock absorbing strut and having a second anchor point arranged to be coupled to the aircraft, the support linkage having a locked condition in which it is arranged to inhibit movement of the main shock absorbing strut from the deployed condition in one or more planes of movement and an unlocked condition in which it permits the main shock absorbing strut to move from the deployed condition to the retracted condition,
the support linkage comprising a split tube spring having a longitudinal slot the spring being biased to assume a tubular condition in which it can react axial loading thereof, and an actuator operable to radially enlarge a region of the tube for the tube to fold at the enlarged region, the support linkage being in the locked condition when the tube is in the tubular condition and being in the unlocked condition when the tube is folded.

2. The aircraft landing gear assembly according to claim 1 , wherein the ends of the split tube spring are coupled to components of the landing gear assembly by fittings which hold the ends of the tube in the tubular condition.

3. The aircraft landing gear assembly according to claim 2 , wherein the end fittings of the tube spring are rigid.

4. The aircraft landing gear assembly according to claim 3 , wherein the end fittings are longer than the length of the split tube spring when in the tubular condition, such that the spring defines a relatively short flexible elbow region between the rigid fittings.

5. The aircraft landing gear assembly according to claim 3 , wherein the end fittings are shorter than the length of the split tube spring when in the tubular condition.

6. The aircraft landing gear assembly according to claim 1 , wherein the support linkage includes a folding stay arm which defines the first and second anchor points, a first end of the split tube spring being coupled to the stay and a second end of the split tube spring being coupled to another part of the landing gear assembly.

7. The aircraft landing gear assembly according to claim 6 , wherein the end fittings of the split tube spring are pivotally coupled to the specified parts of the landing gear assembly.

8. The aircraft landing gear assembly according to claim 1 , wherein the end fittings of the split tube spring define the first and second anchor points.

9. The aircraft landing gear assembly according to claim 8 , wherein the end fittings are rigidly coupled to main strut and airframe respectively.

10. The aircraft landing gear assembly according to claim 8 , further comprising a second bi-stable split line tube coupled at a third anchor point to the main shock absorbing strut and having a fourth anchor point arranged to be coupled to the aircraft, the split tube spring having a tubular, locked condition in which it is arranged to inhibit movement of the main shock absorbing strut from the deployed condition in a plane of movement and an unlocked, folded condition in which it permits the main shock absorbing strut to move from the deployed condition to the retracted condition, the landing gear assembly further including a second actuator operable to radially enlarge a region of the second tube for the second tube to fold at the enlarged region.

11. The aircraft landing gear assembly according to claim 10 , wherein the first and second split tube springs are held within their end fittings such that their split lines are orientated away from one another when the tubes are in the tubular conditions.

12. The aircraft landing gear assembly according to claim 11 , wherein each split tube spring is held within its end fittings such that split line of the split tube spring is can be orientated towards the main strut or the aircraft.

13. An aircraft landing gear assembly according to claim 1 , wherein the split tube spring is held within its end fittings such that split line of the split tube spring is can be orientated towards the main strut or the aircraft.

14. An aircraft landing gear assembly according to claim 1 , wherein the split tube spring is formed from metal or a fibre composite material.

15. An aircraft landing gear assembly including a split tube spring having a longitudinal slot, the spring being coupled to a foldable stay arm and being biased to assume a tubular condition in which it can react axial loading thereof, and an actuator operable to radially enlarge a region of the tube for the tube to fold at the enlarged region, wherein, the split tube spring is configured to lock the stay arm in a generally aligned condition when it is in the tubular condition and is configured to permit folding of the stay arm when it is folded.

16. An aircraft landing gear assembly according to claim 15 , wherein the split tube spring is formed from metal or a fibre composite material.

17. An aircraft landing gear assembly including a split tube spring having a longitudinal slot, the spring being coupled at a first anchor point to the landing gear assembly and having a second anchor point arranged to be coupled to the aircraft, the split tube spring being biased to assume a tubular condition in which it can react axial loading thereof, and an actuator operable to radially enlarge a region of the tube for the tube to fold at the enlarged region, wherein the split tube spring is configured in the tubular condition inhibit movement of the landing gear assembly from a deployed condition to retracted condition and configured permit such movement when folded.

18. An aircraft landing gear assembly according to claim 17 , wherein the split tube spring is formed from metal or a fibre composite material.

19. An aircraft including one or more aircraft landing gear assemblies each comprising:
a main shock absorbing strut arranged to be movably coupled to an aircraft so as to movable between a deployed condition, for take-off and landing, and a stowed condition for flight;
a support linkage coupled at a first anchor point to the main shock absorbing strut and having a second anchor point arranged to be coupled to the aircraft, the support linkage having a locked condition in which it is arranged to inhibit movement of the main shock absorbing strut from the deployed condition in one or more planes of movement and an unlocked condition in which it permits the main shock absorbing strut to move from the deployed condition to the retracted condition,
the support linkage comprising a split tube spring having a longitudinal slot the spring being biased to assume a tubular condition in which it can react axial loading thereof, and an actuator operable to radially enlarge a region of the tube for the tube to fold at the enlarged region, the support linkage being in the locked condition when the tube is in the tubular condition and being in the unlocked condition when the tube is folded.

Assignees

• Safran Landing Systems Uk Ltd
• Safran Landing Systems Uk Ltd

Inventors

• Schmidt Robert Kyle

Classifications

• B64C25/20 Primary

  mechanical · CPC title

• B64C25/34

  wheeled type, e.g. multi-wheeled bogies · CPC title

• B64C25/26 Primary

  Control or locking systems therefor · CPC title

• B64C25/58

  Arrangements or adaptations of shock-absorbers or springs (shimmy-dampers B64C25/50) · CPC title