A burnt-out sealed beam, broken open to show internals. When the lamp burns out the whole assembly (reflector, lamp, lens array) must be replaced. The advantage is very good alignment, and being completely impervious to dirt, moisture, etc.
A sealed beam is a type of lamp that includes a reflector and filament as a single assembly, over which a front cover (lens), usually of clear glass, is permanently attached. The previous design was like that of common flashlights (electric torches), which have a separate small bulb which is fitted in front of a parabolic reflector and covered with a transparent cover, which in the case of a headlamp is ribbed to avoid glare from the filament. This cover would be clamped on with a grommet in between to try to seal it; the method’s deficiencies were what prompted the sealed beam system. The subsequent design has the reflector sealed to the […]