Heater lamp
AssigneeHarison Toshiba Lighting Corp.
InventorsAkio Watanabe, Tetsuo Ootani, Seiji Sakamoto, Minoru Nishizono
Life of this patent
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Abstract
A halogen lamp including a glass bulb, a filament inserted inside the bulb, a pair of metal foils, and a pair of outer leads. Each metal foil has one end welded to the filament and the other end welded to the outer lead. The metal foils are contained in glass sleeves and they are collectively inserted inside the bulb. The bulb is softened by heating and shrinks because its inside pressure is reduced to seal the metal foils therein. Since the amount of glass of each sealed portion is larger than the other portions of the bulb by the amount of the sleeve, the shape of the sealed portion is stabilized.
Claims14
A halogen lamp, comprising:
- a tungsten filament inserted into a bulb made of heat-resistant glass,
- a pair of metal foils whose one ends are connected to both ends of the filament respectively, and
- outer leads for electric power supply connected to the other ends of the individual metal foils with the bulb portions corresponding to the metal foils sealed by a reduced-pressure sealing method,
- wherein an amount of the glass at the portions corresponding to the metal foils is increased, and a cross section c1 of the bulb portion where the filament is housed and a glass cross section c2 of the portion where the metal foil is sealed by the bulb satisfy a relation of c1<c2.
A method for producing a heater lamp, comprising:
- connecting inner leads, metal foils and outer leads in a series state to both ends of a filament;
- housing heat-resistant glass sleeves in a state positioned at the metal foils;
- supporting the filament and others connected in series in the previous step together with the sleeves in a cylindrical bulb made of heat-resistant glass;
- sealing the metal foils and the sleeves by firing by burners with the bulb interior in a pressure-reduced state;
- and
- cutting the bulb portions located outside of the sealed portions formed in the previous step and the outer leads positioned outside of the bulb to an appropriate length.
A method for producing a heater lamp, comprising:
- connecting inner leads, metal foils and outer leads in a series state to both ends of a filament;
- arranging heat-resistant glass sleeves on the outer circumferential surfaces of a bulb portion at the metal foils;
- sealing the sleeves and the bulb portion at the metal foils by firing by burners with the bulb interior in a pressure-reduced state;
- cutting the bulb portion located outside of the sealed portions formed in the previous step and the outer leads positioned outside of the bulb to an appropriate length;
- and
- inserting sleeves made of the same glass as the bulb onto the portions sealed in the previous step and firing the sleeves and the bulb by burners to obtain sealed portions having a desired outer diameter.
A halogen lamp, comprising:
- a coil-shaped filament housed into a cylindrical bulb made of heat-resistant glass;
- a pair of metal foils electrically connected from both ends of the filament through inner leads;
- externally extended outer leads for electric power supply connected to the other ends of the metal foils;
- and
- reduced-pressure sealed portions having the bulb portions at the metal foil portions sealed by a reduced-pressure sealing method,
- wherein at least one of the outer leads is externally extended from the outer circumferential surfaces of the reduced-pressure sealed portions.
14-30. (canceled)
Dependencies are inferred from the claim text.