Welch Allyn, Inc.

Dean A Bell

Timothy D Russell

Richard A Mechowski

Raymond Alan Dean

John W Harkins

A method of making a unitized tungsten electrode which exhibits superior mechanical and electrical properties which includes providing a length of cylindrical cut stock having a predetermined diameter and length. The stock is ground to form a rough unfinished electrode having an enlarged tip or nose portion at one end integrally connected to an elongated shank section. The unfinished electrode is treated by exposure to a chemical etchant for a time sufficient to form a finished electrode characterized by a smooth nose and shank surface and rounded undercut and ends. The invention includes the electrode formed by the described process.

Unitized chemically etched tungsten electrode

Stable electrode design and method

The invention relates to a tungsten electrode which causes minimal cracking when sealed in a quartz glass envelope. The invention includes forming a substantially uniform oxide coating on a selected portion of the shank of a tungsten electrode followed by reducing the oxide coating to substantially elemental tungsten, wherein the electrode exhibits superior properties when sealed in a lamp having a quartz glass envelope. The invention also includes the electrode made by the process.

Electrode surface treatment process

A method for thermal control of a lamp assembly which includes an arc lamp, fan and an associated reflector enclosed within a sealed module. The method includes providing a predetermined air flow path within said module whereby a continuous flow of ambient air is passed over said lamp during lamp operation which reduces the operating temperature of the lamp and increases lamp life, and further including an opening or vent adjacent to the fan which functions to reduce the fan temperature in operation thereby increasing the operating life of the fan.

Lamp and fan thermal control by directed air flow

Electrode treatment surface process for reduction of a seal cracks in quartz

A method for thermal control of a lamp assembly which includes an arc lamp and an associated reflector enclosed within an outer housing. The method includes providing a predetermined air flow path within said housing whereby a continuous flow of ambient air is passed over the lamp during lamp operation which reduces the operating temperature of the lamp and increases lamp life.

Lamp thermal control by directed air flow

A glass halogen lamp which exhibits improved short wavelength light transmission and emission having a glass envelope which is made of a glass composition of the aluminosilicate system in which the iron content of the composition is between 10 and 100 ppm. The glass envelope of the lamp may optionally contain an area of reduced wall thickness which further enhances short wavelength light transmission and emission.

Tungsten halogen lamp

A miniature two-pin, tungsten-halogen lamp in the shape of a cylindrical envelope formed of high temperature glass having a sealed chamber capable of withstanding internal pressures of between 5 and 20 atmospheres. The diameter of the cylindrical envelope is in the range of 0.250 to 0.313 inches and contains at least one refractory metal filament mounted within the sealed chamber. The metal filament is electrically connected to a pair of leads passing out of the envelope. A fill gas is contained within the sealed chamber and contains an inert gas major constituent and a halide gas minor constituent. The lamp produces an efficacy of up to 26 lumens per watt when operating within a range of from 1.25 to 18 watts.

Miniature two-pin tungsten halogen lamp

A low wattage sub-miniature, tungsten-halogen lamp having high efficacy and long life. The lamp has a cylindrical envelope in the T-1 to T-11/4 range containing a fill gas having a halogen minor constituent and an inert gas major constituent. The lamp operates at high fill gas pressures, and lower halogen gas content.

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Marcellus, NY, United States of America

Dean A Bell