Lamp assembly with ventilation system

#The present invention relates to a ventilation system for a lamp assembly, such as an automotive headlamp, fog lamp, signal light, or taillight. More specifically, it relates to a lamp assembly having an optical and/or non-optical shield coupled to a ventilation air passage, such that a cavity of the lamp assembly may be ventilated to an ambient environment.

#A concern that frequently arises during the design of automotive lighting devices is the need to provide proper ventilation for an interior of a housing or body of the lighting device. While adequate ventilation is important for both lighting device functionality and appearance, the automotive lighting device design should also take into account the prevention of fogging of the lighting device lens. Device design should also take into account the unwanted penetration of water, dirt, dust and other contaminants from a surrounding ambient into the lighting device cavity. These design concerns can be especially important where the lighting device resides on the exterior of an automobile that is subject to high speeds, inclement weather, and high water pressure situations (e.g., a car wash).

#Such design concerns also arise when designing an optical and/or non-optical lighting device to ventilate internally generated heat. For example, during use, a bulb of a typical lamp reaches relatively high temperatures. Heat transferred from the bulb can melt, deform, or otherwise damage the lamp housing surrounding the bulb, especially when the lamp housing is made from an inexpensive plastic material. While any side of the lamp housing may have one or more areas susceptible to heat damage, the top side of the lamp housing above the bulb generally suffers the greatest damage due to heat transfer by free, or natural, convection from the bulb.

#FIG. 1 is a back perspective view of a preferred embodiment of a lamp assembly illustrating one aspect of the present invention;

#FIG. 2 is a cross-sectional view of the lamp assembly of FIG. 1 taken along line A—A;

#FIG. 3 is a perspective view of one embodiment of a bulb shield attachment stem;

#Turning now to the drawings, FIGS. 1-2 show a preferred embodiment of a lamp assembly 5 of the present invention. The lamp assembly 5 comprises a lamp bulb 10, a lamp housing 20, a lens 72, and a bulb shield 90. The bulb shield 90 has a bulb shield insert 80 that acts as an engagement mechanism and is preferably spring compression engaged into a vent passage 29.

#The lamp bulb 10 has a light and heat generating filament portion 12, and a socket 14 opposite the filament portion. It should be understood, however, that the socket 14 may be an integral component of the lamp bulb 10, or alternatively, may be a separate component connected to the lamb bulb 10. Although an incandescent bulb is shown in FIG. 1, it should also be understood that any desirable type of lamp bulb may be used with the lamp assembly of the present invention, depending upon regulatory, manufacturing, and/or consumer preferences.

#As shown in FIG. 2, the lamp housing 20 defines a cavity 21. Preferably, but not necessarily, the lamp housing 20 is made from a plastic, such as polycarbonate or ABS.