U.S. Philips Corporation

Josephus J Timmermans

Robert J Pet

Joannes Terheijden

Gijsbert L Von Morgen

Gerardus H A M Van Der Steen

The electric lamp comprises a lamp vessel ( ) in which an electric element ( ) is arranged. The electric element ( ) is connected to feedthroughs ( ) that extend through the wall of the lamp vessel ( ). The respective feedthroughs ( ) comprise a metal shell ( ) and an internal current conductor ( ) connected thereto. The metal shell ( ), which has no knife edge, clamps around the neck-shaped end portion ( ) of the lamp vessel ( ), hence realizing the gastightness of the feedthrough.

Electric lamp with metal shell

The electric incandescent lamp has a quartz glass lamp vessel (1) or envelope (4') around the lamp vessel, which has a red coloured dope in the area at the side of the incandescent body (3). The quartz glass with red dope contains samarium.sup.II oxide, aluminium oxide, titanium dioxide, and silicon dioxide, the analysis of the glass in its oxidized form being Sm.sub.2 O.sub.3 1 to 3% by weight, Al.sub.2 O.sub.3 up to 3% by weight, TiO.sub.2, rest SiO.sub.2, the molar ratio Al/Sm being at least about 2 and the molar ratio Sm/Ti being from 2 to 8.

Method of manufacturing quartz glass for a lamp vessel

An electric lamp has a light source which has an envelope of doped quartz glass. The quartz glass including silicon, cerium, titanium, europium and aluminium in oxidic form. Cerium accounts for 0.1-0.2, titanium for 0.01-0.04, europium for 0.03-0.2 and aluminium for at most 0.8 at % of the cationogenous elements. The aluminium/europium atomic ratio lies in the region from 3 to 8. The doped quartz glass is at least substantially transparent to visible radiation and at least substantially impervious to UV radiation.

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Eindhoven, Netherlands

Josephus J Timmermans