Koninklijke Philips Corporation N.v.

Joseph P Woods

Eswara Vallabhaneni

Karl Baker

Mary E Fortuna

Winand H A M Friederichs

A lamp has a base and a light-transmitting soft-glass lamp envelope sealed to the base to form a sealed lamp cavity which is filled with a non-oxidizing gas. Current supply leads are connected to the stem feedthroughs and extend into the lamp cavity. A halogen incandescent burner is located in the lamp cavity and has a light-transmitting hard-glass burner envelope which encloses a sealed burner cavity filled with an inert gas containing halogen. The burner envelope has presses at its ends. A tungsten filament coil in the burner has extended legs at its ends that extend out of the burner cavity into the lamp cavity through the burner presses and are connected to the current supply leads in the lamp cavity to act as fuses which open upon breach of the lamp envelope, thus preventing further burner operations.

Fuse and safety switch for halogen incandescent lamps

A hard-glass halogen gas-filled incandescent capsule with a single-end or a double-end has a tungsten filament with a primary coil extending from the barrel into the legs, and a secondary coil forming the barrel. One of the legs of the tungsten filament of the single-ended capsule extends into a pinch or press seal of the glass envelope to result in passive extinction of the electric arc at end-of-life. The end of the filament leg near the press seal may be connected to and/or supported by a molybdenum lead wire of the capsule that is within the pinch or the press seal via a clamp formed on the molybdenum lead wire. The passive extinction occurs when the electric arc is conducted through the filament extending into the press seal. Reliable extinction of the arc within the capsule is achieved with simplicity in construction and minimal materials. The primary coil is preferably stretched out to assume the diameter of the tungsten wire where it is embedded in a pinch seal. This hastens extinction of the arc at end of life and also simplifies manufacture by eliminating close tolerance requirements in the clamp.

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Eindhoven, Netherlands

Joseph P Woods