Patent ID: 6078136
Filing Date: 2000-06-20
Classification: F21V,F21W,H01J

Abstract:
In a fluorescent lamp with a protective assembly,the lamp having an elongated glass tube and a metal terminal cap at each end of the glass tube and each cap having a flange portion adjacent the glass tube, andthe protective assembly having a protective tube preformed from a semi-rigid non-frangible polymeric transparent or translucent material that is stabilized against ultraviolet radiation, the protective tube being received over the glass tube, being joined at the ends to the flange portions of the terminal caps, having an inner surface substantially uniformly spaced apart from an outer surface of the glass tube to form an air space for insulation of the lamp, and being substantially coextensive with the glass tube lengthwise of the lamp,the improvement whereinthere is a multiplicity of vent holes in portions of the protective tube proximate to the terminal caps of the lamp, the vent holes being of a size such that if the lamp breaks fragments of the glass tube cannot pass through the holes and the number of holes being sufficient to enable the lamp to operate without substantial discoloration and without a substantial reduction in light output at ambient temperatures in the range of from about 50.degree. F. to about -30.degree. F.