Double shell fastener caps

Patent metadata

Field	Value
Publication number	US-11022164-B2
Application number	US-201816209088-A
Country	US
Kind code	B2
Filing date	Dec 4, 2018
Priority date	Sep 11, 2018
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A cover that extends over a fastener and methods of installing the cover over the fastener. The cover includes an open end positioned at a member from which the fastener extends. The cover also includes a closed end that extends over the fastener and shields the fastener from the exterior environment that can be combustible. The cover includes an outer shell with one or more windows. An inner shell is positioned within the outer shell. The inner shell includes one or more windows that are offset from the windows of the outer shell. One or more flow paths extend through the windows for gas, liquid, and/or some particles to flow through the cover while removing the thermal and/or kinetic energy that may ignite the combustible exterior environment.

First claim

What is claimed is:

1. A cover comprising:
an inner shell comprising a first end that is open, a second end, and an interior space sized to extend over a fastener, the inner shell having a window open to the interior space and positioned between the first end and the second end;
an outer shell that shrouds the inner shell, the outer shell comprising a first end that is open and a second end, the outer shell further comprising a window positioned between the open end and the second end, the window of the outer shell being aligned away from the window of the inner shell to prevent a line of sight from an exterior of the outer shell to the interior space of the inner shell;
a gap between the inner shell and the outer shell; and
a flow path that extends between the interior space of the inner shell and the exterior of the outer shell, the flow path extending to and through the window of the inner shell, the window of the outer shell, and the gap.

2. The cover of claim 1 , wherein the outer shell comprises an inner side that faces towards the gap and the inner shell comprises an outer side that faces towards the gap, the outer shell comprising a larger inner width and the inner shell comprising a smaller outer width with the gap formed between the outer side and the inner side.

3. The cover of claim 1 , wherein the outer shell comprises an inner side that faces towards the inner shell and the inner shell comprises an outer side that faces towards the outer shell, the inner side and the outer side being in contact along one or more sections of the cover away from the gap.

4. The cover of claim 1 , wherein the window of the inner shell is a first window of the inner shell and the window of the outer shell is a first window of the outer shell, the cover further comprising a second window that extends through the inner shell and a second window that extends through the outer shell, each of the first and second windows of the outer shell being offset from each of the first and second windows of the inner shell to prevent a line of sight from the exterior of the outer shell to the interior space of the inner shell.

5. The cover of claim 4 , wherein the first and second windows of the inner shell comprises between 0.1%-90% of a surface area of the inner shell and the first and second windows of the outer shell comprises between 0.1%-90% of the surface area of the outer shell.

6. The cover of claim 1 , wherein each of the first ends of the inner shell and the outer shell are aligned on a contact plane, and wherein the window of the outer shell is positioned away from the window of the inner shell to prevent a line of sight from the exterior of the outer shell to the contact plane.

7. The cover of claim 1 , further comprising an extension that extends from one of the inner shell or the outer shell, and further comprising a receptacle that is positioned in the other of the inner shell or the outer shell, the extension engaged with the receptacle to prevent rotation and translation of the inner shell relative to the outer shell.

8. The cover of claim 1 , wherein the cover is attached to the fastener to secure the cover to the fastener.

9. The cover of claim 1 , further comprising a base attached to the inner shell and to the outer shell, and a gasket positioned at an end of the base with the gasket configured to conform between the base and a member.

10. The cover of claim 9 , wherein the interior space of the inner shell is sized to extend over two or more of the fasteners.

11. The cover of claim 10 , wherein the cover is mounted in a fuel cell of an aircraft and configured to quench an ignition event in the fuel cell triggered by an ignition source associated with a fastener.

12. The cover of claim 10 , further comprising a retaining feature in each of the inner shell and the outer shell, the retaining features being engaged together to prevent rotation of the inner shell relative to the outer shell about a longitudinal axis of the cover.

13. A cover comprising:
an inner shell and an outer shell that are nested together in an overlapping arrangement that includes an open end and a closed end, each of the inner shell and the outer shell comprising:
a first end that is open;
an interior space;
at least one window in communication with the respective interior space; and
a second end that opposes the respective first end;

one or more gaps between the outer shell and the inner shell;
at least one flow path that extends outward from the interior space within the inner shell to an exterior of the outer shell, the at least one flow path extending through at least one of the windows of the inner shell, at least one of the windows of the outer shell, and one of the one or more gaps that extend between the windows;
the at least one window of the inner shell is offset from the at least one window of the outer shell to prevent a line of sight from an exterior of the outer shell to the interior space within the inner shell.

14. The cover of claim 13 , wherein each of the at least one flow paths comprises at least one section with a hydraulic diameter that is between 0.1 mm-2.0 mm.

15. The cover of claim 13 , wherein each of the inner shell and the outer shell comprise two or more windows and the cover comprises a plurality of flow paths with each of the flow paths extending from a different one of the windows of the inner shell, a different one of the windows of the outer shell, and a different one of the gaps.

16. A method of installing a cover over a fastener, the method comprising:
positioning a cover over a fastener that extends from a member with the fastener positioned in an interior space of an inner shell and with an outer shell extending over the inner shell and with the inner and outer shells mated together to prevent relative movement;
aligning the cover over the fastener with a window through the outer shell being misaligned with a window of the inner shell and preventing line of sight from an exterior on the outer shell to the interior space of the inner shell and the fastener from being visible from the exterior of the outer shell, the window of the inner shell is positioned between first and second ends of the inner shell and the window of the outer shell is positioned between first and second ends of the outer shell; and
forming a flow path that extends from the interior space of the inner shell to the exterior of the outer shell with the flow path extending through the window of the inner shell, along a gap formed between the inner shell and the outer shell, and through the window of the outer shell.

17. The method of claim 16 , further comprising the flow path having at least one section with a hydraulic diameter between 0.1 mm-2.0 mm.

18. The method of claim 16 , further comprising connecting a base of the cover to the fastener.

19. The method of claim 18 , further comprising positioning the cover over a second one of the fasteners.

20. The method of claim 16 , further comprising attaching the inner shell to the outer shell and preventing movement of the inner shell relative to the outer shell.

Assignees

• Boeing Co

Inventors

• Roper Christopher Stephen
• Schubert Randall Colin
• Kwon Eddie
• Damazo Jason S
• Hansen Darrin M
• O'Masta Mark Randall
• Stilke Morgan A

Classifications

• B29C45/0001

  characterised by the choice of material · CPC title

• B64D37/005 Primary

  Accessories not provided for in the groups B64D37/02 - B64D37/28 · CPC title

• F16B33/004 Primary

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

• B29K2027/18

  PTFE, i.e. polytetrafluoroethylene {, e.g. ePTFE, i.e. expanded polytetrafluoroethylene} · CPC title

• B64D37/32

  Safety measures not otherwise provided for, e.g. preventing explosive conditions · CPC title