Patent Application
20080182502
The present invention relates to a system and method for ventilating enclosures. More specifically, the present invention relates to a system and method of ventilating an automotive lighting enclosure.
Automotive lighting enclosures typically are heated by the light sources they enclose. The air in the light enclosure expands when heated by the operation of the light sources and contracts when cooled to ambient temperature by the deactivation of the light sources. The amount of expansion and contraction can be significant and, unless the enclosure is vented, can result in an unsafe overpressure condition in the enclosure. Such an overpressure condition could cause serious injury should the enclosure shatter or break in a collision or because of the overpressure condition.
Accordingly, automotive lighting enclosures are typically vented to the atmosphere to provide pressure relief for expanding and/or contracting gases within the enclosure. However, as automotive lighting systems typically include reflectors, lenses and/or other optical components and various electrical components, it is desired to prevent the ingress of foreign materials, and particularly water, into the enclosure through the vent.
To date, automotive lighting enclosures have typically been provided with vents equipped with filters to prevent the ingress of foreign materials. Most commonly, these filters comprise a sheet of a suitable filter material, such as Goretex™ or a foam, which is affixed over the vent exit.
While such filter-based vents have worked, they do suffer from disadvantages in that the filter must be installed in a separate manufacturing step and the filter material can degrade over time and/or is expensive to purchase.
Other approaches have been to provide a convoluted vent path through which atmosphere can exit and enter the lighting enclosure without the heed for a filter. Ideally, the convoluted path includes one or more turns which utilize gravity to inhibit rain or other sprayed water from entering the lighting enclosure through the vent path. However, such systems are often less than satisfactory as water droplets or other materials in the convoluted path can still be drawn into the lighting enclosure by the decreased pressure in the enclosure when the enclosure cools after use. This decreased pressure acts as a vacuum, relative to the atmospheric pressure surrounding the enclosure, and will draw in water or other foreign materials on the convoluted path.
It is desired to have a ventilation system and method for automotive lighting systems which does not suffer from such disadvantages.
It is an object of the present invention to provide a novel ventilation system and method for automotive lighting systems which obviates or mitigates at least one disadvantage of the prior art.
According to the present invention, there is provided a lighting enclosure having: a body; a lens, the lens being bonded to the body; a vent on the body, the vent including at least two closed tortuous paths, each tortuous path extending between a passage through the body and at least one respective port exposed to the atmosphere outside the body, each tortuous path including a portion over which foreign material is separated by gravity from atmosphere moving into the enclosure and each tortuous path providing a path independent of the other path between the atmosphere and the vent passage to allow atmosphere to enter and exit the enclosure.
Preferably, each tortuous path is formed between upstanding ribs, the body of the enclosure and a cover plate. In one embodiment, the upstanding ribs are integrally formed on the body and the cover plate is affixed to the ribs. In another embodiment, the upstanding ribs are integrally formed on the cover plate and the ribs are affixed to the body.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
An automotive lighting enclosure with a vent in accordance with the present invention is indicated generally at 20 in
To prevent the ingress of foreign material into enclosure 20, lens 28 is bonded to body 24 such that the joint between body 24 and lens 28 is substantially air and water tight. To allow for the expansion and contraction of the air within enclosure 20, a vent 36 in accordance with the present invention, is included on body 24 as illustrated.
As can be best seen in
To prevent the ingress of foreign material, such as water, to the interior of enclosure 20, vent 36 defines two tortuous paths 44 and 48 (indicated by the different hatching patterns in
Air from within enclosure 20 can exit the enclosure through vent passage 40 and through either or both of paths 44 and 48, ultimately exiting enclosure 20 through one or more of ports 52, 56, 60 and 64. Similarly, air can enter enclosure 20 from the surrounding atmosphere via one or more of ports 52, 56, 60 and 64 and then via one or both of paths 44 and 48 to vent passage 40 and then into the interior of enclosure 20.
Each tortuous path 44 and 48 includes path portions which are orientated at least partially vertically, such that gravity assists in separating water or other foreign materials from air moving through the paths. Water or other foreign material entering ports 52 or 60 will move down and exit ports 56 or 64 under the impetuous of gravity. Water or other foreign material entering ports 56 or 64 will not be drawn towards vent passage 40 as air will instead enter through ports 52 or 60.
As should now be apparent, the provision of two separate paths 44 and 48 between the respective ones of ports 52, 56, 60 and 64 and vent passage 40 prevents the ingress of foreign material, and in particular water, into enclosure 20. Specifically, and unlike prior art systems with a convoluted path, by providing two separate paths 44 and 48 between vent passage 40 and ports 52, 56, 60 and 64, if water or other foreign material blocks one of paths 44 or 48, air can still travel into or out of enclosure 20 through the other of paths 44 and 48.
As will be apparent, unlike prior art convoluted path solutions, a reduced pressure within enclosure 20 will not result in foreign material in either path 44 or 48 being “vacuumed” into enclosure 20 as air will instead be drawn through either path 44 or 48 without the foreign material. This is much different than prior art enclosures with convoluted path vents where, if a water droplet or other foreign material was in the path, the water or foreign material could be vacuumed into the enclosure as air was drawn into the enclosure through the convoluted path.
Vent 36 can be molded in place, as illustrated in
It is also contemplated that vent 36 can be fabricated as a separate unit, as shown in
It is also contemplated that vent 36 can be fabricated as a separate unit with cover plate 68 in place, as shown in
While each of the embodiments discussed above only include two tortuous paths 44 and 48, the present invention is not so limited and vents 36 can include three or more paths, if desired. However, it is contemplated that in many circumstances two paths will be sufficient. Further, while each of the embodiments described above preferably includes at least two ports for each path, the present invention is not so limited and can be employed with a single port per path, or with more than two ports per path, if desired.
The present invention provides a ventilation system and method for automotive lighting systems and includes at least two tortuous paths between the interior of the lighting enclosure and the surrounding atmosphere. The two paths include portions which are oriented at least partially vertically and gravity assists in separating foreign material from air drawn through these portions. By providing at least two paths, foreign material in one path will not be drawn into the enclosure as air can still pass through the other path. The ventilation system and method can be integrally formed with the enclosure, or can be separately formed and attached to the enclosure.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
