U.S. Philips Corporation

Koninklijke Philips Corporation N.V.

Antonius J Spaapen

Frans J Traksel

Theodorus J Van Gennip

Frank Gerardus Cornelis De Bot

Cornelis J Van Den Broek

Pieter Dirk Melis Van Duivendijk

Johannes Tj Van Haastrecht

An electric lamp has a cap, which is secured to a light-transmitting lamp vessel having an electric element. The lamp cap has a projecting contact pin. An electric conductor is connected to the electric element and the contact pin. The contact pin is unilaterally deformed in an inward direction so as to form an indentation for fixing the electric conductor. The electric conductor in the contact pin does not extend substantially beyond a boundary of the indentation. The indentation has a pinch portion. The pinch portion deepens at an angle a with respect to the axis, where 25&deg;&lE;&agr;&lE;45&deg;. In addition, the indentation has a press portion for fixing the electric conductor in the contact pin.

Capped electric lamp and low-pressure mercury-vapor discharge lamp

A capsule (20) having a glass wall (21) and containing mercury is positioned in a radiation-transmitting discharge vessel, after which the discharge vessel is provided with a rare gas and closed, means for maintaining an electric discharge are arranged in or adjacent the discharge vessel. The capsule is opened by fusion after the discharge vessel has been closed by heating the capsule by irradiation (42) with a parallel beam of radiation through the wall of the discharge vessel. The wall of the capsule has for this radiation an absorption coefficient which amounts at least ten times that of the wall portion of the discharge vessel.

Method of manufacturing a low-pressure mercury discharge lamp

In a method according to the invention, a capsule (20) having a glass wall (21) and containing mercury is positioned in a radiation-transmitting discharge vessel, after which the discharge vessel is provided with a rare gas and closed, means for maintaining an electric discharge are arranged in or adjacent the discharge vessel, and the capsule is opened by fusion after the discharge vessel has been closed in that the capsule is heated by irradiation (42) with a parallel beam of radiation through the wall of the discharge vessel. The wall of the capsule has for this radiation an absorption coefficient which amounts at least ten times that of the wall portion of the discharge vessel. The method according to the invention renders possible a comparatively simple lamp construction. A low-pressure mercury discharge lamp is provided with a radiation-transmitting discharge vessel (10) which is closed in a gastight manner and has an ionizable filling comprising mercury, while a capsule (20) with a glass wall (21) having an opening (24) is arranged in the discharge vessel, and the lamp is in addition provided with means (31A, 31B) for maintaining an electric discharge in a discharge space (13) surrounded by the discharge vessel. The capsule (20) is accessible to radiation of at least a wavelength lying in a range from 100 nm to 5 .mu.m from outside the discharge vessel (10) through a wall portion (11) thereof, and the wall (21) of the capsule (20) has an absorption coefficient for this radiation which amounts at least ten times that of the wall portion (11) of the discharge vessel.

Low-pressure mercury discharge lamp having mercury capsule with a

Electrodeless low-pressure discharge lamp

A method of manufacturing a low-pressure mercury vapor discharge lamp with a discharge vessel comprising two or more substantially parallel co-extending glass discharge tube portions (4 and 5) interconnected through a coupling which extend transversely to the wall of said tube portions. First, the inner wall of an elongate tube is provided with a luminescent material. Then, while heating at least a short zone of the wall, the elongate tube is then divided into two portions. End walls are formed during the division on which the luminescent layer extends the thickness of the tube wall and the temperature of the heated zone are chosen so that no particles of the luminescent material are enclosed in the glass of the end wall during said dividing process and fracture is avoided at least after cooling. At least at the area of the transition from the end wall to the tube wall, the ratio AB/CD is 0.4 to 0.8.

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Roosendaal, Netherlands

Antonius J Spaapen