End-of-life protection for compact fluorescent lamps
View Patent ↗A self-ballasted fluorescent lamp ( 10 ) that comprises a housing ( 12 ) formed to contain a ballast. The housing ( 12 ) has a top surface ( 14 ) with openings ( 16 ) leading from the exterior of the housing ( 12 ) to the interior. The openings ( 16 ) can be in the form of raised bosses having upstanding walls ( 16 a ). A restricted portion ( 18 ), which can take the form of a flange, is formed with the opening ( 16 ) and a safe end-of-life enabling device ( 20 ) is positioned in the opening ( 16 ) and in contact with the restricted portion ( 18 ). The safe end-of-life device ( 20 ) is tubular, has low thermal conductivity and in preferred forms of the invention is a glass such as quartz or a ceramic such as aluminum oxide. The ends ( 22 ) of a fluorescent lamp ( 24 ) penetrate the tubular end-of-life device ( 20 ) and extend into the interior of the housing for suitable connection to an enclosed electronic ballast. A retainer ( 26 ) is positioned opposite the restricted portion for maintaining the end-of-life device within the opening. The retainer ( 26 ) is a typical compact fluorescent cement that is used to fix the lamp to the housing. Alternatively, the retainer can be an adhesive silicone or a threaded washer.
1. A self-ballasted fluorescent lamp comprising:
a housing formed to contain a ballast;
a top surface for said housing;
an opening in said top surface leading from an exterior of said housing to an interior of said housing;
a restricted portion formed with said opening;
a safe end-of-life enabling device positioned in said opening and in contact with said restricted portion;
ends of a fluorescent lamp penetrating said end-of-life enabling device; and
a retainer positioned opposite said restricted portion for maintaining said end-of-life enabling device within said opening.
2. The self-ballasted fluorescent lamp of claim 1 wherein said safe end-of-life enabling device has low thermal conductivity.
3. The self-ballasted fluorescent lamp of claim 2 wherein said safe end-of-life enabling device is constructed from a glass or ceramic.
4. The self-ballasted fluorescent lamp of claim 3 wherein said glass is quartz.
5. The self-ballasted fluorescent lamp of claim 3 wherein said ceramic is aluminum oxide.
6. The self-ballasted fluorescent lamp of claim 1 wherein said lamp is of a double spiral tube type.
7. The self-ballasted fluorescent lamp of claim 1 wherein said retainer is a fluorescent lamp cement.