Cap for forming sealed cavity around fastener

Patent metadata

Field	Value
Publication number	US-9506493-B2
Application number	US-201514952729-A
Country	US
Kind code	B2
Filing date	Nov 25, 2015
Priority date	Feb 10, 2011
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A joint having a structure and a fastener passing through the structure. A cap has a body portion with an annular base terminating at an edge, the body portion forming an enclosure around an end of the fastener. The cap also has an annular flange which extends outwardly from the body portion and is set back from the edge of the base so as to define a pocket between the flange and the base. A sealant is provided in the pocket between the flange and the base, the sealant bonding the cap to the structure via a sealant/cap interface with the cap and a sealant/structure interface with the structure. The surface area of the sealant/cap interface is greater than the surface area of the sealant/structure interface.

First claim

The invention claimed is:

1. A joint comprising:
a. a structure;
b. a fastener passing through the structure;
c. a cap comprising:
i. an inner body portion with an annular base terminating at an edge, the body portion forming an enclosure around an end of the fastener, and
ii. an outer body portion with an annular flange which extends outwardly from the inner body portion and is set back from the edge of the base so as to define a pocket between the flange and the base; and

d. a sealant in the pocket between the flange and the base, the sealant bonding the cap to the structure via a sealant/cap interface with the cap and a sealant/structure interface with the structure,
wherein the surface area of the sealant/cap interface is greater than the surface area of the sealant/structure interface.

2. The joint of claim 1 wherein the ratio between the surface area of the sealant/cap interface and the surface area of the sealant/structure interface is greater than 150%.

3. The joint of claim 1 wherein at least part of the annular flange extends at an angle of less than 90° to the annular base.

4. The joint of claim 3 wherein at least part of the annular flange extends at an acute angle to the annular base, and wherein the acute angle is less than 90° but greater than 0°.

5. The joint of claim 1 wherein the annular flange has an edge which is set back from the structure.

6. The joint of claim 1 wherein the edge of the annular base engages the structure.

7. The joint of claim 1 wherein the annular flange has an edge which is set back from a plane defined by the edge of the annular base.

8. The joint of claim 1 wherein the annular flange begins to extend outwardly from the body portion at a point which is set back from the edge of the annular base.

9. The joint of claim 1 wherein the annular base has inwardly extending lugs which engage the fastener.

10. The joint of claim 1 wherein the inner body portion forms a sealed cavity around the end of the fastener.

11. The joint of claim 1 wherein the ratio between the surface area of the sealant/cap interface and the surface area of the sealant/structure interface is greater than 200%.

12. A cap for forming a sealed cavity around one end of a fastener, the cap comprising an inner cap member with an annular base terminating at an edge which surrounds an opening into a central cavity; and an outer cap member which fits over the inner cap member and has an annular base which forms an annular flange extending outwardly from the inner cap member at a point which is set back from the edge of the annular base of the inner cap member so as to define a pocket between the flange and the base.

13. The cap of claim 12 wherein at least part of the annular flange extends at an angle of less than 90° to the annular base.

14. The cap of claim 12 wherein at least part of the annular flange extends at an acute angle to the annular base of the inner cap member, and wherein the acute angle is less than 90° but greater than 0°.

15. The cap of claim 12 wherein the annular flange has an edge which is set back from a plane defined by the edge of the annular base of the inner cap member.

16. The cap of claim 12 wherein the annular flange begins to extend outwardly from the inner cap member at the point which is set back from the edge of the annular base of the inner cap member.

17. The cap of claim 12 wherein the annular base of the inner cap member has inwardly extending lugs.

18. The cap of claim 12 further comprising a flow channel between the inner cap member and the outer cap member which leads into the pocket.

19. The cap of claim 12 wherein the inner and outer cap members have a curved domed shape.

20. The cap of claim 12 wherein the inner and outer cap members are formed from a polymer.

21. A kit of parts comprising an inner cap member with an annular base terminating at an edge which surrounds an opening into a central cavity; and an outer cap member which is sized to fit over the inner cap member and shaped to form an annular flange which extends outwardly from the inner cap member at a point which is set back from the edge of the base when the outer cap member is fit over the inner cap member.

22. A method of installing a cap to form a sealed cavity around one end of a fastener, the fastener passing through a structure, the cap comprising an inner cap member with an annular base terminating at an edge which surrounds an opening into a central cavity, and an outer cap member which fits over the inner cap member and has an annular base which forms an annular flange extending outwardly from the inner cap member at a point which is set back from the edge of the annular base of the inner cap member so as to define a pocket between the flange and the base of the inner cap member, the method comprising:
a. fitting the inner cap member over the one end of the fastener so that it is enclosed by the inner cap member;
b. providing a flow of sealant material between the inner cap member and the outer cap member into the pocket; and
c. adhering the cap to the structure with the sealant material which flowed into the pocket.

23. A joint comprising:
a. a structure;
b. a fastener passing through the structure;
c. a cap comprising:
i. a body portion with an annular base terminating at an edge, the body portion forming an enclosure around an end of the fastener, and
ii. an annular flange which extends outwardly from the body portion and is set back from the edge of the base so as to define a pocket between the flange and the base; and

d. a sealant in the pocket between the flange and the base, the sealant bonding the cap to the structure via a sealant/cap interface with the cap and a sealant/structure interface with the structure,

wherein the surface area of the sealant/cap interface is greater than the surface area of the sealant/structure interface, and wherein the body portion and the flange are formed integrally as a single piece of material.

24. The joint of claim 23 wherein the ratio between the surface area of the sealant/cap interface and the surface area of the sealant/structure interface is greater than 200%.

25. The joint of claim 23 wherein at least part of the annular flange extends at an angle of less than 90° to the annular base.

26. The joint of claim 23 wherein at least part of the annular flange extends at an acute angle to the annular base, and wherein the acute angle is less than 90° but greater than 0°.

27. The joint of claim 23 wherein the annular flange has an edge which is set back from the structure.

28. The joint of claim 23 wherein the annular flange has an edge which is set back from a plane defined by the edge of the annular base.

29. The joint of claim 23 wherein the annular flange begins to extend outwardly from the body portion at a point which is set back from the edge of the annular base.

30. The joint of claim 23 wherein the annular base has inwardly extending lugs which engage the fastener.

31. The joint of claim 23 wherein the body portion forms a sealed cavity around the end of the fastener.

32. The joint of claim 23 wherein the structure comprises a composite material.

33. The joint of claim 32 wherein the composite material is a laminar fibre-reinforced composite mate

Assignees

• Airbus Operations Ltd

Inventors

• Dobbin Richard

Classifications

• F16B33/004 Primary

  Sealing; Insulation (by means of washers F16B43/001) · CPC title

• F16B37/14

  Cap nuts; Nut caps or bolt caps · CPC title

• B64C1/12

  Construction or attachment of skin panels · CPC title

• B64D45/02

  Lightning protectors; Static dischargers · CPC title

• Y10T29/49948

  Multipart cooperating fastener [e.g., bolt and nut] · CPC title