High sensitivity, load alleviating load sensor for strut application

Patent metadata

Field	Value
Publication number	US-9459168-B2
Application number	US-201414222061-A
Country	US
Kind code	B2
Filing date	Mar 21, 2014
Priority date	Mar 22, 2013
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A load-sensing strut has a main body ( 26 ) having a longitudinal loading axis (A) along which an applied load is transmitted, and a load sensing member ( 38 ) arranged to carry at least a portion of the applied load when the load is within a predetermined range, wherein the load sensing member ( 38 ) includes at least one load sensor ( 46 ) generating a load signal. The strut also has a load alleviation member ( 36 ) arranged to reduce the portion of the applied load carried by the load sensing member ( 38 ) when the applied load is outside the predetermined loading range. Consequently, the load sensors exhibit greater sensitivity to incremental changes in the applied load within the predetermined range, yet the strut provides high strength and is capable of reacting to very high loads outside of the predetermined range. The strut may be used in actuating aircraft control surfaces in a high-lift system.

First claim

What is claimed is:

1. A load-sensing strut comprising:
a main body having a longitudinal loading axis along which an applied load is transmitted;
a load sensing member arranged to carry at least a portion of the applied load when the applied load is within a predetermined loading range, wherein the load sensing member includes at least one load sensor generating a load signal, wherein the load sensing member includes a cylindrical sleeve aligned on the loading axis; and
a load alleviation member arranged to reduce the portion of the applied load carried by the load sensing member when the applied load is outside the predetermined loading range, wherein the load alleviation member includes an outer tube member surrounding the main body to define first and second longitudinal abutment gaps between the main body and the load alleviation member whereby the load alleviation member is disengaged from transmitting the applied load when the applied load is within the predetermined loading range;
the load alleviation member being engaged to assist the main body and the load sensing member in transmitting the applied load in response to longitudinal deformation of the main body caused by the applied load being outside the predetermined loading range;
wherein the at least one load sensor exhibits greater sensitivity to incremental changes in the applied load when the applied load is within the predetermined loading range than when the applied load is outside the predetermined loading range.

2. The load-sensing strut according to claim 1 , wherein the predetermined loading range includes a tension load and a compression load.

3. The load-sensing strut according to claim 1 , further comprising a preload member operable to apply an axially-directed preload to the load sensing member.

4. The load-sensing strut according to claim 1 , wherein the preload member is a nut threadably adjustable relative to the main body to apply a preload to the load sensing member.

5. The load-sensing strut according to claim 1 , wherein the at least one load sensor comprises a first plurality of load sensors applied to a surface of the cylindrical sleeve and angularly spaced about the loading axis at a first axial location.

6. The load-sensing strut according to claim 5 , wherein the at least one load sensor further comprises a second plurality of load sensors applied to the surface of the cylindrical sleeve and angularly spaced about the loading axis at a second axial location spaced from the first axial location.

7. The load sensing strut according to claim 1 , wherein the load alleviation member is aligned on the loading axis.

8. The load sensing strut according to claim 1 , wherein the load alleviation member is situated between a collar arranged about the main body and an abutment ring arranged about the main body.

9. The load sensing strut according to claim 8 , wherein main body includes a flange opposing the collar to define an annular space between the flange and the collar, and the load alleviation member includes an internal radial step received in the annular space.

10. The load sensing strut according to claim 9 , further comprising an elastically deformable member arranged between the flange and the collar, wherein the elastically deformable member maintains the first gap between the flange and the internal radial step and the second gap between the collar and the internal radial step when the applied load is within the predetermined loading range.

11. The load sensing strut according to claim 10 , wherein at least one of the first gap and the second gap closes when the applied load is outside of the predetermined loading range.

12. The load sensing strut according to claim 1 , wherein the main body includes an intermediate wall extending along the loading axis radially inward from the load alleviation member, and wherein the applied load is transmitted through the load sensing member and the intermediate wall, and not through the load alleviation member, when the applied load is within the predetermined loading range.

13. The load sensing strut according to claim 12 , wherein the applied load is transmitted through the load sensing member, the intermediate wall, and the load alleviation member when the applied load is outside of the predetermined loading range.

Assignees

• Moog Inc

Inventors

• Kohuth Kerry Randall
• Pedersen Derek

Classifications

• B64D2045/0085

  Devices for aircraft health monitoring, e.g. monitoring flutter or vibration · CPC title

• B64C9/20

  by multiple flaps · CPC title

• B64C9/16 Primary

  at the rear of the wing · CPC title

• B64C13/34

  using toothed gearing · CPC title

• G01N3/08

  by applying steady tensile or compressive forces (G01N3/28 takes precedence) · CPC title