AIRCRAFT SPRING ASSEMBLY

• US 20160347444A1
• Filed: 05/17/2016
• Published: 12/01/2016
• Est. Priority Date: 06/01/2015
• Status: Active Grant

• Current Assignee: Safran Landing Systems UK Limited (Safran SA)
• Original Assignee: Messier-Dowty Limited (Safran SA)
• Inventors: Greenwood, Paul, Paddock, Andrew, Vatovec, Andraz
• Granted Patent: US 10,279,896 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64C 25/20 mechanical
• CPC Class Codes: B64C 25/26 Control or locking systems therefor
• CPC Class Codes: B64C 25/62 Spring shock-absorbers; Springs
• CPC Class Codes: B64C 25/64 using rubber or like elements
• CPC Class Codes: F03G 1/10 for producing output movement other than rotary, e.g. vibratory
• CPC Class Codes: F16F 3/04 composed only of wound springs
• CPC Class Codes: F16F 3/10 combined with springs made of steel or other material having low internal friction

Abstract

An aircraft spring assembly having a spring, an end fitting including a spring engagement formation arranged to be mechanically coupled to an end region of the spring and a coupling formation for coupling the spring assembly to an aircraft anchor point. The coupling formation includes a load bearing surface via which loads from the anchor point can be transmitted into the spring assembly. The assembly further includes an integral damping member provided within the load path between the load bearing surface of the coupling formation and the end region of the spring.

Claims

1. An aircraft spring assembly comprising:

a mechanical spring;

an end fitting including;

a spring engagement formation arranged to be mechanically coupled to an end region of the spring; and

a coupling formation for coupling the spring assembly to an aircraft anchor point, the coupling formation including a load bearing surface via which loads from the anchor point can be transmitted into the spring assembly; and

at least one integral damping member provided within the load path between the load bearing surface of the coupling formation and the end region of the spring in order to decrease the amplitude of mechanical waves induced in the spring due to loads applied to the load bearing surface of the coupling formation.

2. An aircraft spring assembly according to claim 1, wherein the spring comprises a helical coil spring.

3. An aircraft spring assembly according to claim 1, wherein the damping member is provided within an axial load path between the load bearing surface of the coupling formation and the end region of the spring in order to decrease the amplitude of longitudinal mechanical waves induced in the spring due to axial loads applied to the load bearing surface of the coupling formation.

4. An aircraft spring assembly according to claim 3, further comprising one or more guards, each being arranged to contain one of the damping members and having first and second side portions arranged on opposite side of the respective damping member, the guard being configured such that the side portions can move relative to one another along the axis of the spring to compress the damping member.

5. An aircraft spring assembly according to any claim 1, wherein the coupling formation comprises a cylindrical internal sidewall defining a hole arranged to receive a bush which defines the load bearing surface, at least one of the damping members being disposed within the hole between the cylindrical internal sidewall and the bush.

6. An aircraft spring assembly according to claim 5, wherein the bush defines one of the side portions of the guard.

7. An aircraft spring assembly according to claim 1, wherein the spring engagement formation comprises an annular fitting having an outer surface arranged to engage the spring and a cylindrical internal sidewall defining an axial hole arranged to slidably house a rod, a first end of the rod defining or being coupled to an end stop of greater diameter than the axial hole, and a second end of the rod defining the coupling formation, at least one of the damping members being mounted between the end stop and annular fitting so as to dampen axial movement of the rod relative to the annular fitting in a first direction.

8. An aircraft spring assembly according to claim 7, comprising a projection extending radially from the rod between the coupling formation and the annular fitting and wherein at least one of the damping members is mounted between the projection and annular fitting so as to dampen axial movement of the rod relative to the annular fitting in a second direction which is opposite to the first direction.

9. An aircraft spring assembly according to claim 1, wherein one or more of the damping members each comprises a generally annular member formed from a resilient material which is relatively soft in comparison to the end fitting and/or the spring.

10. An aircraft spring assembly according to claim 9, wherein the annular member is formed from an elastomer material.

11. An aircraft spring assembly according to claim 1, wherein one or more of the damping members each comprises a second spring which is less stiff than the first spring.

13. An aircraft including one or more spring assemblies according to claim 1.

12. An aircraft landing gear assembly comprising:

an aircraft spring assembly comprising;

a mechanical spring;

a first end fitting including;

a first spring engagement formation arranged to be mechanically coupled to a first end region of the spring, and

a first coupling formation for coupling the spring assembly to an aircraft anchor point, the coupling formation including a load bearing surface via which loads from the anchor point can be transmitted into the spring assembly;

at least one integral damping member provided within the load path between the load bearing surface of the coupling formation and the end region of the spring in order to decrease the amplitude of mechanical waves induced in the spring due to loads applied to the load bearing surface of the coupling formation; and

a second end fitting;

a first part attached to the first end fitting; and

a second part movably mounted with respect to the first part and attached to the second end fitting, wherein the first and second parts comprise elements of a side stay, a lock link or elements of each.

14. An aircraft including one or more aircraft landing gear assemblies according to claim 12.