Tungsten-fluorine lamp with native retained oxygen therein and method of manufacture

Claim 1

A tungsten halogen lamp comprising a glass bulb having walls defining a sealed cavity, a tungsten filament within said bulb having spaced apart legs, a filament support means on one end of said bulb including metallic current leads and metallic foil means for connecting said metallic current leads to the legs of said tungsten filament, a fill gas mixture in said cavity including an inert gas and a gaseous fluorinated hydrocarbon consisting only of carbon, fluorine and bromine and having a composition of 3.2 × 10.sup. -7 to 8 × 10.sup. -7 gram atoms of carbon, 2.1 × 10.sup. -6 to 5.2 × 10.sup. -6 gram atoms of bromine and 1.5 × 10.sup. -6 to 3.8 × 10.sup. -6 gram atoms of fluorine per cc of cavity volume, said bulb walls, tungsten filament and filament support means having native retained oxygen thereon releasable upon bulb operation to add a further fill gas constituent of free oxygen in the range of 1.3 × 10.sup. -6 to 3.3 × 10.sup. -6 gram atoms per cubic centimeter of cavity volume to balance the gram atom constituent of the fill gas in the form of free fluorine released during bulb operation.

Claim 3

A method for fabricating a tungsten halogen lamp comprising the steps of forming a glass envelope including a tubulation on one end thereof and an open end on the opposite end thereof, preforming a tungsten filament and mount assembly including a filament component having two legs joined to current leads by means of lenticular molybdenum foil members to form a tungsten filament and lead set, locating the current leads, foil components and filament through the open end of the envelope on a lead set mount having a tapered surface thereon facing in the open direction of the envelope, directing a cover gas through the envelope of the tubulation thereon through the open end thereof and across the tapered surface of the lead set mount to maintain a smooth gas flow across the filament lead set, thereafter heating and hermetically press sealing the envelope to the molybdenum foils to produce a hermetic seal of the envelope with respect to the foil to retain a quantity of native oxygen on the lead set releasable upon bulb operation to add a fill gas constituent of free oxygen in the range of 1.3 × 10.sup. -6 to 3.3 × 10.sup. -6 gram atoms per cubic centimeter of a final cavity volume, evacuating the bulb through the tubulation to approximately 1 × 10.sup. -5 torr and thereafter filling the bulb with inert gas of 99.995% purity and a concentration of a gaseous fluorinated hydrocarbon consisting only of carbon, fluorine and bromine having quantities in the range of 3.2 × 10.sup. -7 to 8 × 10.sup. -7 gram atoms of carbon, 2.1 × 10.sup. -6 to 5.2 × 10.sup. -6 gram atoms of bromine and 1.5 × 10.sup. -6 to 3.8 × 10.sup. -6 gram atoms of fluorine (all per cubic centimeter of the total cavity volume), and thereafter sealing the tubulation.

Claim 4

A method for fabricating a tungsten halogen lamp comprising the steps of forming a glass envelope including a tubulation on one end thereof and an open end on the opposite end thereof, preforming a tungsten filament and mount assembly including a filament component having two legs joined to current leads by means of lenticular molybdenum foil members to form a tungsten filament and lead set, locating the current leads, foil components and filament through the open end of the envelope on a lead set mount having a tapered surface thereon facing in the open direction of the envelope, directing a cover gas through the envelope of the tubulation thereon through the open end thereof and across the tapered surface of the lead set mount to maintain a smooth gas flow across the filament lead set, thereafter heating and hermetically press sealing the envelope to the molybdenum foils to produce a hermetic seal of the envelope with respect to the foil to retain a quantity of native oxygen on the lead set releasable upon bulb operation to add a fill gas constituent of free oxygen in the range of 1.3 × 10.sup. -6 to 3.3 × 10.sup. -6 gram atoms per cubic centimeter of a final cavity volume, evacuating the bulb through the tubulation to approximately 1 × 10.sup. -5 torr and thereafter filling the bulb with inert gas of 99.995% purity and a concentration of a gaseous fluorinated hydrocarbon consisting only of carbon, fluorine and bromine having quantities in the range of 3.2 × 10.sup. -7 to 8 × 10.sup. -7 gram atoms of carbon, 2.1 × 10.sup. -6 to 5.2 × 10.sup. -6 gram atoms of bromine and 1.5 × 10.sup. -6 to 3.8 × 10.sup. -6 gram atoms of fluorine (all per cubic centimeter of the total cavity volume), and thereafter sealing the tubulation.