Landing gear assembly and methods

Patent metadata

Field	Value
Publication number	US-9764826-B2
Application number	US-201314647586-A
Country	US
Kind code	B2
Filing date	Nov 19, 2013
Priority date	Nov 27, 2012
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A landing gear assembly having a first part movable relative to a second part, and a spring coupled to the first and second parts via first and second anchor points. A lost motion assembly is provided to enable one of the anchor points to translate along one of the parts. As such, the spring extends less as the first part moves relative to the second part than it would if each anchor point was fixed to a respective part.

First claim

The invention claimed is:

1. A landing gear assembly comprising:
a first elongate member;
a second elongate member movably coupled to the first elongate member; and
a spring coupled to the first elongate member via an anchor at a first end region of the spring, and movably coupled to the second elongate member via a lost motion assembly at a second end region of the spring, the lost motion assembly comprising:
a rod coupled to the second elongate member so as to move with the second elongate member;
a shackle connected between the spring and the rod and arranged to clasp the rod so as to be slidably coupled thereto; and
first and second end stops arranged to limit travel of the shackle along the rod, thereby defining respective first and second travel limit points on a longitudinal axis of the rod,

wherein the lost motion assembly is arranged such that:
with the first elongate member at a first angular position with respect to the second elongate member, the distance between the first travel limit point and the anchor is less than the distance between the second travel limit point and the anchor; and
with the first elongate member at a second angular position with respect to the second elongate member that is distinct from the first angular position, the distance between the first travel limit point and the anchor is greater than the distance between the second travel limit point and the anchor.

2. A landing gear assembly according to claim 1 , wherein the rod extends generally parallel with respect to the portion of the surface of the second elongate member to which it is coupled.

3. A landing gear according to claim 1 , wherein the rod is arranged such that its longitudinal axis is non-orthogonal with respect to the longitudinal axis of the second elongate member.

4. A landing gear assembly according to claim 1 , wherein the longitudinal axis of the rod and longitudinal axis of the second member are orientated at an angle of at least 10 degrees with respect to one another.

5. A landing gear assembly according to claim 1 , wherein the shackle surrounds the rod.

6. A landing gear assembly according to claim 1 , wherein the first angular position is at least 5 degrees from the second angular position.

7. A landing gear assembly according to claim 1 , wherein angular spacing between the first and second angular positions is less than 120 degrees.

8. A landing gear assembly according to claim 1 , wherein the first angular position corresponds to the landing gear assembly being in, or close to, the deployed condition.

9. A landing gear assembly according to claim 1 , wherein the second angular position corresponds to the landing gear assembly being in, or close to being in, the stowed condition.

10. A landing gear assembly according to claim 1 , wherein the first member comprises a stay arm and the second member comprises a lock link.

11. A landing gear assembly according to claim 1 , wherein the rod is attached to the second elongate member by a pair of brackets that define the respective limit points.

12. A landing gear assembly according to claim 1 , wherein the spring comprises a down lock spring.

13. An aircraft including a landing gear assembly according to claim 1 .

14. A method of moving a landing gear assembly between a retracted condition and a deployed condition, the method comprising:
moving a first elongate member relative to a second elongate member to which the first elongate member is coupled, said movement changing the extension state of a spring that is coupled to the first elongate member via an anchor at a first end region of the spring, and that is movably coupled to the second elongate member via a lost motion assembly at a second end region of the spring, the lost motion assembly comprising:
a rod coupled to the second elongate member so as to move with the second elongate member;
a shackle connected between the spring and the rod and arranged to clasp the rod so as to be slidably coupled thereto; and
first and second end stops arranged to limit travel of the shackle along the rod, thereby defining respective first and second travel limit points on the longitudinal axis of the rod,
whereby said movement changes the orientation of the rod relative to the second elongate member such that:
with the first elongate member at a first angular position with respect to the second elongate member, the distance between the first travel limit point and the anchor is less than the distance between the second travel limit point and the anchor; and
with the first elongate member at a second angular position with respect to the second elongate member that is distinct from the first angular position, the distance between the first travel limit point and the anchor is greater than the distance between the second travel limit point and the anchor.

Assignees

• Safran Landing Systems Uk Ltd

Inventors

• Paddock Andrew
• Empson Paul

Classifications

• B64C25/26 Primary

  Control or locking systems therefor · CPC title