Patent Grant
7191845
1. Field of the Invention
This invention relates to a fire-rated, self-closing vent for soffits and walls connecting the exterior of a building to its interior. The vent comprises a screen surrounded by a peripheral frame, the combination having no moving parts. The screen comprises cells which are coated with an intumescent. Under normal conditions the cells are open to freely pass air therethrough and serves to ventilate crawl spaces, attics, etc. When subjected to the elevated temperatures of an external fire, the intumescent expands to close the cells, thus preventing flames, heat, and gaseous fumes from entering the building.
2. Description of Related Art
A major problem, especially in Southern California and other dry areas, is the occurrence of wildfires, mainly brush fires and forest fires, and the concomitant damage they do to property in their paths. Homes, offices, and other buildings are constructed and maintained so as to prevent the spread of internal fires from one room to another. Included in this effort is the use of an intumescent coated screen or grill as a self-closing vent in interior walls, floors, ceilings, or ventilation ducts, all of which provide open air-flow between rooms under normal conditions but which close when exposed to high temperatures. The patents of record are representative of the prior use of intumescent coated, self-closing vents for internal walls, ceilings, floors, and ventilation ducts. A close reading, however, reveals that they have not been applied to external walls, soffits, etc. The assumption has been that the fire is internal of the building, i.e., one that has started within the building, and the emphasis has been on containing fires within the interiors of buildings long enough for the inhabitants thereof to make their safe escape. Little attention has been given to vents connecting the exterior with the interior of buildings, probably because protecting the spread of an internal fire to the outside of a building has only a minor influence on occupants' safety. As a consequence, the protection of homes from the entrance of external fires has been largely overlooked, leaving buildings, especially homes, ready prey for an external fire. Firefighters and homeowners attempt to protect the homes in the paths of a wildfire by hosing down the roof and exterior walls with water, but all their efforts are in vain, when the fire enters through vents in the external walls and guts the building from the inside.
The present invention overcomes the difficulties described above by providing a self-closing vent designed to replace existing vents which connect the exterior of a building with its interior.
The present invention accomplishes the above by providing a self-closing vent coated with an intumescent, said self-closing vent being added to an external wall or soffit either as original equipment or as a replacement for existing vents.
It is an object of the invention to provide a self-closing vent which prevents an external fire from entering a building through vents which connect the exterior of a building with its interior.
The foregoing and other objects, aspects, uses, and advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when viewed in conjunction with the accompanying drawings, in which:
Referring to
Vents opening externally of the building are usually designed to freely promote circulation, and no thought has been given to closing them. Soffit vents 22 and 38 are often just holes formed in external siding, since being beneath the eaves 24 and 40 of an overhanging second story 26 and roof 42, respectively, they are not directly exposed to the weather. Attic vents 44 usually comprise either an open-mesh screen covering an opening into attic 36 or a plurality of fixed, overlapping louvers, if it is anticipated that the vent will be exposed to wind-blown rain or snow. All of these vents are permanently open. Crawl space vents 20 are the exception, especially in colder climates where it is desirable to have them closed during the winter months to prevent the loss of heat through floor 50. Vents 20 usually comprise vanes journalled in perimetrical frames, the vanes being rotatable from horizontally spaced to vertically overlapping. Some vents 20 comprise a pair of apertured plates, one of which is fixed while the other slides relative thereto to align or to close the apertures. Both are opened and closed mechanically, usually by hand by direct action of a human being. In the event of fires, external or internal, no one takes the time to close vents 20, and, of course, soffit vents 28 and 30 and attic vents 42 cannot be closed.
The inventor recognized that exterior vents provide unintended entries of external fires and should be automatically closed when exposed to an approaching wildfire. (Hot gasses produced by internal fires also should not be allowed to exit through the vents, for this draws fresh air into the building which feeds the fire, but that is not the primary object of this invention.) The invention is therefore directed toward vents which are designed to allow free passage of airflow through external walls under normal circumstances but to close when subjected to high temperatures as would be experienced from an external wildfire.
Turning to
In one preferred embodiment, the peripheral edge 72 of screen 58 is rigidly secured within hollow interior 70 of body 56 by any convenient means, such as by welding, brazing, or by an epoxy adhesive. In this preferred embodiment, there is no relative movement of screen 58 and frame 60, so self-closing vent 52 can be literally characterized as a rigid, integral structure with no moving parts.
Other embodiments will also fall within the scope of the disclosed invention. For instance, frame 60 could be constructed without leg 66 and with screen 58 secured either to leg 64 or web 68, or both. So long as flange 54 of frame 60 can be fastened to the external surface of wall 46 and holds screen 58 such that it covers the vent opening (not shown) in the wall, the desired results of the invention will be effected.
In the simplest construction, screen 50 is cut to shape, and frame 60 is assembled around it. In this most preferred embodiment, screen 58 is not integral with frame 60, but rather peripheral edge 72 fits loosely within hollow interior 70 of body 56 and is completely contained therein. Even though slight movement is possible between screen 58 and frame 60, vent 52 is considered for patent purposes as having no moving parts, inasmuch as any relative movement is inconsequential, producing neither a useful function nor any ill effects. Peripheral edge 72 follows the contours of frame 60 very close to web 68, so it will be appreciated that screen 58 entirely covers central opening 62 (
Screen 58 preferably comprises a honeycomb structure having hexagonal cells 74 which are open through screen 58 from front 76 to back 78. Screen 58 is about ⅝th inches thick and is preferably comprised of walls 80 formed of 3 mil stock aluminum. Cells 74 are preferably substantially ¼ inch in cross-section. U-shaped body 56 completely encloses any sharp edges that peripheral edge 72 may have suffered during construction of screen 58. With frame 60 having a reasonably smooth exterior itself, vent 52 is without sharp edges, a feature which facilitates the handling, storage, and transporting thereof.
Vent 52 is coated in its entirety with an intumescent material. The coating is preferably about 10 mils thick, so it is apparent that virtually the entire width of each cell 74 is open under ambient conditions for free flow of air. When exposed to high temperatures, such as those associated with a fire, however, the intumescent material expands and carbonizes to form a solid barrier which is impenetrable by heat or by gasses.
The shape and dimensions of vent 52 will vary depending upon the intended location of use. A typical set of dimensions for vent 52 is as follows: (1) The outside dimensions of flange 54 are approximately 7.25 inches by 15.25 inches. (2) The outside dimensions of U-shaped body 56 are approximately 5.75 inches by 11.75 inches. (3) The thickness of screen 58 is approximately 0.63 inches. (4) The width of web 68 is approximately 0.69 inches. And, (5) the width of legs 64 and 66 of U-shaped body 56 is approximately 0.50 inches.
In use, for new building constructions, a vent opening is formed whereever appropriate in the external walls (the term “external wall” as used herein and in the claims incorporates any externally exposed structure, including first or second story wall 46, eaves 24 and 40, and the wall surrounding crawl space 18), and body 56 of self-closing vent 52 is fit therein. Flange 54 of frame 60 is attached to the outside surface of wall 46 around the vent opening. To retrofit self-closing vent 52 to an existing building, the building's external vents are removed, and each are replaced with a self-closing vent 52 mounted on the exterior wall or eave as before. Flange 54 is pressed flat upon wall 46 with U-shaped body 56 extending inwardly therefrom into a vent opening through the exterior wall or eave. Vent 52 is either shaped to fit an existing aperture, or a new aperture is formed having a dimension such that a standard body 56 fits snugly therewithin. Flange 54 is then fixed to the exterior wall 58 by suitable fasteners, e.g., screws, nails, etc. As is apparent from
It is clear from the above that the objects of the invention have been fulfilled.
Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention as defined in the appended claims.
Further, the purpose of the foregoing Abstract is to enable the U.S. Patent and Trademark Office, and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of the application, which is measured solely by the claims, nor is intended to be limiting as to the scope of the invention in any way.
It can be seen from the above that an invention has been disclosed which fulfills all the objects of the invention. It is to be understood, however, that the disclosure is by way of illustration only and that the scope of the invention is to be limited solely by the following claims:
| Number | Name | Date | Kind |
|---|---|---|---|
| 2279791 | Lamb | Apr 1942 | A |
| 3976825 | Anderberg | Aug 1976 | A |
| 4093818 | Thwaites et al. | Jun 1978 | A |
| 4722158 | Urdaneta | Feb 1988 | A |
| 5957211 | Geuken et al. | Sep 1999 | A |
| 6256948 | Van Dreumel | Jul 2001 | B1 |
| Number | Date | Country |
|---|---|---|
| 1500913 | Feb 1974 | GB |
| 2107183 | Aug 1982 | GB |
| Number | Date | Country | |
|---|---|---|---|
| 20040069506 A1 | Apr 2004 | US |
