Halogen incandescent capsule having filament leg clamped in press seal

摘要

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.