Fastener systems that provide EME protection

Patent metadata

Field	Value
Publication number	US-9611052-B2
Application number	US-201314073806-A
Country	US
Kind code	B2
Filing date	Nov 6, 2013
Priority date	Mar 29, 2012
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

Fasteners are inserted into a stack of members and terminated with parts having at least one of a dry dielectric coating and an inner dry dielectric seal at select locations to protect against electromagnetic effects (EME).

First claim

The invention claimed is:

1. A method comprising inserting fasteners into a stack of members and terminating the fasteners with parts having at least one of a dry dielectric coating and an inner dry dielectric seal at select locations to protect against electromagnetic effects (EME).

2. The method of claim 1 , wherein the seal is used to protect against arcing, sparking and hot particle ejection; and wherein the coating is used to protect against arcing and sparking.

3. The method of claim 1 , wherein the members are aircraft members, at least one of which is made of composite material.

4. The method of claim 1 , wherein the members include aircraft skin and a metal member.

5. The method of claim 1 , wherein at least one of the fasteners is interference-fitted into a through hole in the stack.

6. The method of claim 1 , wherein terminating the fasteners includes using at least one part having a central opening and at least one EME protective feature including a dry dielectric coating and a dry inner dielectric seal, the seal secured to and protruding axially from the central opening.

7. The method of claim 1 , wherein at least some of the fasteners are terminated with a combination of a washer and nut, the washer having an inner proximal seal and an outer surface coated with a dielectric coating, the nut having an outer proximal seal, an inner proximal seal, and an inner distal dielectric coating.

8. The method of claim 1 , wherein at least some of the fasteners are terminated with a combination of a washer and nut, the washer having an inner proximal seal, the nut having an inner proximal seal, an inner distal dielectric coating, and an exterior dielectric coating.

9. The method of claim 1 , wherein at least some of the fasteners are terminated with a combination of a washer and nut, the washer having an inner proximal seal and a concentric ridge at a periphery of the washer, the nut having an inner proximal seal, an inner distal seal, and an exterior dielectric coating.

10. The method of claim 1 , wherein at least some of the fasteners are terminated with a combination of a washer and nut, the washer having outer and inner proximal seals, the nut having an exterior dielectric coating and an inner proximal coating.

11. The method of claim 1 , wherein at least some of the fasteners are terminated with nuts having a counterbore, height of the counterbore being between about 3.1% to 59.0% of nut height, diameter of the counterbore being between about 51.4% and 79.05% of nut diameter.

12. The method of claim 1 , wherein at least some of the fasteners are terminated with a nut having an outer dielectric seal at a proximal location, the seal having a thickness between about 2.0% to 15.0% of nut diameter, and a height between about 2.2% and 22.3% of nut height.

13. A method comprising inserting fasteners into a stack of members and terminating the fasteners with parts having a combination of dry dielectric coating and a dry dielectric seal at select locations to protect against electromagnetic effects (EME) without using sealant.

14. A part for terminating a fastener, the part comprising:
a fastener termination body having a central opening; and
at least one feature for protecting against EME effects, the at least one feature including at least one of a dry dielectric coating and a dielectric seal partially covering the central opening at a select location, the seal secured to the body, the coating and the seal having a thickness and composition for inhibiting lightning current, the select location including at least one of a distal location and a proximal location.

15. The part of claim 14 , wherein the seal protrudes axially at least 7 mils from the body.

16. The part of claim 14 , further comprising a dielectric coating completely covering an exterior surface of the body.

17. The part of claim 14 , wherein the part is a collar.

18. The part of claim 17 , wherein the dielectric seal is at a distal location on the collar.

19. The part of claim 17 , wherein collar's body further has counterbore, height of the counterbore being between about 3.1% to 59.0% of collar height, diameter of the counterbore being between about 51.4% and 79.05% of collar diameter.

20. The part of claim 17 , further comprising an outer dielectric seal on the body at a proximal location, the seal having a thickness between about 2.0% to 15.0% of collar diameter, and a height between about 2.2% and 22.3% of collar height.

21. The part of claim 20 , wherein the collar has a retention channel for retaining the outer proximal seal, and a metal backing outboard of the seal.

22. The part of claim 17 , wherein the at least one feature includes both the dielectric coating and the dielectric seal.

23. The part of claim 14 , wherein the part is a washer.

24. The part of claim 23 , wherein the at least one feature includes the dielectric seal partially covering the central opening at a proximal location of the washer.

25. The part of claim 24 , wherein the at least one feature further includes a second seal covering the central opening at a distal location of the washer, the seals separated by a gap.

26. The part of claim 25 , further comprising a dielectric coating on an exterior surface of the washer.

27. The part of claim 24 , further comprising a concentric ridge protruding from at least one face of the washer.

28. A fastening system comprising a fastener, at least one fastener termination part, and EME protective features for the fastener and each fastener termination part, the EME protective features taken from the group consisting of:
a conductive resin coating on a shaft of the fastener;
an interlocked dielectric cover on a head of the fastener;
an inner dielectric seal on a proximal location of the fastener head;
a dielectric seal on a distal location of the termination part;
a dielectric seal on a proximal location of the termination part;
a dielectric coating on a distal location of the termination part; and
a dielectric coating on a proximal location of the termination part.

29. The fastening system of claim 28 , wherein the dielectric seal is used to protect against arcing, sparking and hot particle ejection; and wherein the dielectric coating is used to protect against arcing and sparking.

Assignees

• Boeing Co

Inventors

• Whitlock Richard P
• Coronado Peter A
• Morden Sean D
• Rogers Randall A

Classifications

• F16B33/004

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

• Y10T29/49888

  Subsequently coating · CPC title

• F16B33/06

  Surface treatment of parts furnished with screw-thread, e.g. for preventing seizure {or fretting (corrosion preventing means F16B33/008; settable coatings for locking threaded members F16B39/225; deformable coatings for locking threaded members F16B39/34)} · CPC title

• B64D45/02 Primary

  Lightning protectors; Static dischargers · CPC title