Venting member

Abstract

A venting member includes a fastener and a gas-permeable member positioned at least partially within the fastener to allow movement of a gas through the fastener, but prevent movement of liquids.

Description

The invention was conceived or reduced to practice in the performance of work under U.S. Government contract #N00019-93-C-0196 award by the U.S. Navy.

FIELD OF THE INVENTION

This invention relates generally to venting members, and more particularly to venting members configured to vent enclosures.

BACKGROUND OF THE INVENTION

Enclosures are used in a wide range of applications and generally provide a protective environment for an electrical component housed in the enclosure. Such an electrical component is housed in the enclosure typically because the component may be damaged when it is exposed to environmental agents, such as water or a lubricant.

It is sometimes desirable to vent the sealed enclosure to allow pressure equalization between the gases inside the sealed enclosure and the gases in the environment surrounding the sealed enclosure. Venting the enclosure can prevent damage to its internal components, by preventing excessive pressure or vacuum within the enclosure.

Various methods are currently used to vent an enclosure housing. One such method includes forming a hole or an aperture through the enclosure so that it is not fluid-tight. The aperture allows the passage of gases and liquids between the interior of the enclosure and the enclosure's surroundings, however, the aperture also allows liquids to enter the enclosure. To protect the electrical components, a drain hole is typically formed in the enclosure to allow liquid accumulated in the enclosure to drain. Also, the electrical component is typically potted or encased with an epoxy material to prevent contact with liquid in the enclosure. However, this method is somewhat undesirable because of the costs associated with potting electrical components and because the epoxy tends to retain heat given off by the electrical components, and in many instances the electrical components cannot be potted because the potting material degrades performance or prevents operation.

SUMMARY OF THE INVENTION

The present invention attempts to address the shortcomings of current methods of venting an enclosure by providing a venting member including a fastener and a gas-permeable member positioned at least partially within the fastener to allow movement of a gas through the fastener.

The present invention also provides a vented assembly including a venting member including a fastener and a gas-permeable member positioned at least partially within the fastener to allow movement of a gas through the fastener. The vented assembly also includes at least one wall defining in part an enclosure. The fastener couples to the at least one wall to fluidly connect a space inside the enclosure and a space outside the enclosure.

Further, the present invention provides a venting member including a fastener including a body portion and a head portion. The body portion defines a longitudinal axis. The venting member also includes an aperture formed through the body portion and the head portion, and a gas-permeable member positioned at least partially within the aperture to allow gas to pass through the fastener via the aperture.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, wherein like reference numerals indicate like parts:

FIG. 1 is a perspective cutaway view of a venting member of the present invention;

FIG. 2 is a cross-sectional view of the venting member of FIG. 1 coupled to a wall of an enclosure, illustrating a first configuration of the venting member; and

FIG. 3 is a cross-sectional view of the venting member of FIG. 1 coupled to the wall of the enclosure, illustrating a second configuration of the venting member.

Before at least one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limited.

DETAILED DESCRIPTION

A venting member 10 in the form of a fastener 14 is shown in FIG. 1. The venting member 10 is configured to be coupled to a wall 18 (see FIGS. 2-3) of an enclosure (not shown) to provide a passageway for gases to move between a space inside the enclosure and the environment outside the enclosure. In the illustrated construction, the fastener 14 is in the form of a bolt or a cap screw having a threaded body portion 22 and a head portion 26 configured to be engaged by a tool (not shown). However, in other constructions of the venting member (not shown), the venting member may be in the form of any of a number of different fasteners, such as, but not limited to, a rivet or a nail. Also, depending on the application, the fastener 14 may be made from metal or plastic.

As shown in FIG. 1, an aperture 30 is formed through the fastener 14 along a longitudinal axis 34 defined by the body portion 22 of the fastener 14. A first reduced-diameter portion 38 of the aperture 30 is located at an end of the aperture 30 near the head portion 26 of the fastener 14, and a second reduced-diameter portion 42 of the aperture 30 is located at an opposite end of the aperture 30. A gas-permeable member 46 is supported in the aperture 30 and secured therein between the first and second reduced-diameter portions 38, 42. In the illustrated construction, the gas-permeable member 46 is cylindrical in shape and press-fit within the aperture 30. Also, in the illustrated construction, the gas-permeable member 46 extends substantially along the entire length of the threaded body 15 of fastener 14. Alternatively, the gas-permeable member 46 may be a substantially planar membrane extending across the aperture 30. Further, in yet other constructions of the venting member (not shown), the gas-permeable member 46 may define any of a number of different shapes, and may be configured in any of a number of different lengths along the longitudinal axis 34.

The gas-permeable member 46 allows the passage of gases through the aperture 30, while blocking the passage of liquids through the aperture 30. The press-fit connection between the gas-permeable member 46 and the aperture 30 ensures that substantially no liquids leak through the aperture 30. The gas-permeable member 46 may be made from a single piece of polytetrafluoroethylene (PTFE), otherwise known by the trade name TEFLON®. Alternatively, the gas-permeable member 46 may include a core (not shown) made from another gas-permeable polymeric material and a PTFE coating over the core. In yet other constructions of the venting member (not shown), other polymers or a gas-permeable ceramic material may be used to achieve an acceptable permeability rate for a particular application of the venting member.

As shown in FIG. 1, a screen 50 is also supported in the aperture 30 between the gas-permeable member 46 and the first reduced-diameter portion 38. The screen 50 is configured to protect the gas-permeable member 46 from being damaged by contact with particles, tools, or the like. In the illustrated construction, the screen 50 is made from metal and is compressed between the gas-permeable member 46 and the first reduced-diameter portion 38 of the aperture 30.

The venting member 10 may be manufactured in any of a number of different ways. However, in the illustrated construction, the aperture 30 and first reduced-diameter portion 38 are initially formed in the fastener 14. The screen 50 is then inserted adjacent the first-reduced diameter portion 38, and the gas-permeable member 46 is press-fit into the aperture 30 to compress the screen 50 against the first reduced-diameter portion 38. Further, the second reduced-diameter portion 42 is formed by a crimping process to secure the gas-permeable member 46 and the screen 50 in the aperture 30.

FIGS. 2-3 illustrate respective vented assemblies 54, 56 with each vented assembly 54, 56 including the venting member 10 being coupled to the wall 18 of the enclosure. The threaded body portion 22 of the fastener 14 threadably engages a threaded aperture 58 through the wall 18. As shown in FIG. 2, a first configuration of the venting member 10 includes a seal 62 in the form of an O-ring 66 being preloaded against the wall 18 by the head portion 26 of the fastener 14. The O-ring 66 provides a seal such that leakage of gases and/or liquids through the threaded aperture 58 in the wall 18 is substantially prevented by the O-ring 66. In other constructions of the vented assembly (not shown), the seal 62 may take any of a number of different forms, including, but not limited to, a rubber washer and a paper-based gasket.

FIG. 3 shows a second configuration of the venting member 10 including a thread-locking device 70 coupled to the threaded body portion 22 of the fastener 14 and the threaded aperture 58 in the wall 18. In the illustrated construction, the thread-locking device 70 is in the form of a conventional thread-locking adhesive 74 applied between the threaded body portion 22 of the fastener 14 and the threaded aperture 58 in the wall 18. The thread-locking adhesive 74 provides a seal such that leakage of gases and/or liquids through the threaded aperture 58 in the wall 18 is substantially prevented.

The enclosure may house components (not shown) for use in any of a number of different applications. The venting member 10 of the present invention is especially useful for venting a enclosure housing electrical components. Such electrical components could be damaged if they were to come into contact with liquids. Since the venting member 10 allows the movement of gases between the interior and exterior of the enclosure while blocking the corresponding movement of liquids, the electrical components are protected from the liquid, and do not require additional protective structure (e.g., a potting compound). Some of the different applications whereby the venting member 10 may be used may include, but are not limited to, field electronics enclosures, outdoor lighting enclosures, avionics enclosures subject to altitude-related pressure changes, and marine applications subject to intermittent water exposure.

Claims

1. A venting member, comprising:

a fastener; and

a gas-permeable member positioned at least partially within the fastener to allow movement of a gas through the fastener.

2. The venting member of claim 1, wherein the fastener is at least one of a screw and a bolt.

3. The venting member of claim 1, wherein the fastener defines a longitudinal axis, and wherein the fastener includes an aperture formed therethrough substantially parallel to the longitudinal axis, the aperture receiving the gas-permeable member.

4. The venting member of claim 1, wherein the fastener has an aperture, and wherein the gas-permeable member is positioned at least partially within the aperture.

5. The venting member of claim 1, wherein the fastener has an aperture, and wherein the gas-permeable member is press-fit within the aperture.

6. The venting member of claim 1, wherein the fastener has an aperture with opposite ends, and wherein opposite ends of the gas-permeable member are exposed to the respective opposite ends of the aperture.

7. The venting member of claim 1, further comprising a screen at least partially positioned in the fastener.

8. The venting member of claim 1, wherein the gas-permeable member is configured as a cylinder.

9. The venting member of claim 1, wherein the gas-permeable member is configured to block movement of liquids through the fastener.

10. The venting member of claim 1, wherein the fastener has an aperture, and wherein at least one portion of the aperture has a reduced diameter to retain the gas-permeable member therein.

11. A vented assembly comprising:

a venting member including a fastener, and a gas-permeable member positioned at least partially within the fastener to allow movement of a gas through the fastener; and

at least one wall defining in part an enclosure, the fastener coupling to the at least one wall to fluidly connect a space inside the enclosure and a space outside the enclosure.

12. The vented assembly of claim 11, wherein the fastener defines a longitudinal axis, and wherein the fastener includes an aperture formed therethrough substantially parallel to the longitudinal axis.

13. The vented assembly of claim 11, wherein the fastener has an aperture, and wherein the gas-permeable member is positioned at least partially within the aperture.

14. The vented assembly of claim 11, wherein the fastener has an aperture with opposite ends, and wherein opposite ends of the gas-permeable member are exposed to the respective opposite ends of the aperture.

15. The vented assembly of claim 11, further comprising a screen at least partially positioned in the fastener.

16. The vented assembly of claim 11, wherein the gas-permeable member is configured as a cylinder.

17. The vented assembly of claim 11, wherein the gas-permeable member is configured to block movement of liquids through the fastener.

18. The vented assembly of claim 11, wherein the fastener has an aperture, and wherein at least one portion of the aperture has a reduced diameter to retain the gas-permeable member therein.

19. The vented assembly of claim 11, further comprising a seal preloaded against the at least one wall by the fastener, the seal fluidly sealing the space inside the enclosure from the space outside the enclosure.

20. The vented assembly of claim 11, wherein the at least one wall includes a threaded aperture therethrough, and wherein the fastener is at least one of a screw and a bolt threadably engageable with the threaded aperture.

21. The vented assembly of claim 20, further comprising a thread-locking device coupled to at least one of the fastener and the threaded aperture, wherein the thread-locking device fluidly seals the space inside the enclosure from the space outside the enclosure when the fastener is threadably engaged with the threaded aperture.

22. A venting member comprising:

a fastener including a body portion and a head portion, the body portion defining a longitudinal axis;

an aperture formed through the body portion and the head portion; and

a gas-permeable member positioned at least partially within the aperture to allow gas to pass through the fastener via the aperture.

23. The venting member of claim 22, wherein the fastener is at least one of a screw and a bolt.

24. The venting member of claim 22, further comprising a screen at least partially positioned in the fastener near the head portion of the fastener.

25. The venting member of claim 22, wherein the gas-permeable member is configured as a cylinder.

26. The venting member of claim 22, wherein the gas-permeable member is configured to block movement of liquids through the fastener via the aperture.

27. The venting member of claim 22, wherein at least one portion of the aperture has a reduced diameter to retain the gas-permeable member therein.