Lamp with a bulb made of a high silica content glass
AssigneePatent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH
InventorWerner Weiss
Life of this patent
Estimating the term…
Abstract
To improve tightness of a pinch or press seal (2a; 13a, 13b) between a modenum foil and quartz or similar hard glass of an electric lamp, typically a halogen incandescent lamp or metal halide discharge lamp, an intermediate melt glass layer in form of a strip is applied to the sealing foil, which has the following main components: SiO.sub.2 : 60-70% Al.sub.2 O.sub.3 : 3-20% K.sub.2 O: 12-18, all percentages by weight, the glass being, except for trace contaminants, free from Na.sub.2 O. In a preferred form, the main components are: SiO.sub.2 : 66% Al.sub.2 O.sub.3 : 18% K.sub.2 O: 15%, all percentages by weight.
Claims18
Electric lamp (1, 12) having
- a bulb (2, 13) of a glass which has a silicon oxide content of at least 96%;
- current supply leads (4, 5, 8, 9;
- 16, 17, 20, 21) extending, respectively, within the bulb and outwardly from the bulb;
- foil connections including two foils (6, 7;
- 18, 19) each having two sides located between the current supply leads extending inwardly and outwardly, respectively, from the bulb;
- a solder glass layer located between the glass of the bulb and the respective side of the foil;
- and
- a melt connection, vacuum-tightly melting the foil connections into an end portion of the bulb,
- wherein, in accordance with the invention,
- the solder glass has the characteristic of high wetting and adhesion capability with respect to the foil connection quartz glass system to prevent oxidation of the foils,
- said solder glass being, except for trace contaminants, free from Na.sub.2 O, and having the following main components:
- SiO.sub.2 :
- 60-70%
- A1.sub.2 O.sub.3 :
- 3-20%
- K.sub.2 O:
- 12-18%,
- all percentages by weight.
Electric lamp (1, 12) having
- a bulb (2, 13) of a glass which has a silicon oxide content of at least 96%;
- current supply leads (4, 5, 8, 9;
- 16, 17, 20, 21) extending, respectively, within the bulb and outwardly from the bulb;
- foil connections including two foils (6, 7;
- 18, 19) each having two sides located between the current supply leads extending inwardly and outwardly, respectively, from the bulb;
- a solder glass located between the glass of the bulb and the respective side of the foil;
- and
- a melt connection, vacuum-tightly melting the foil connections into an end portion of the bulb,
- wherein, in accordance with the invention,
- the solder glass has the characteristic of high wetting and adhesion capability with respect to the foil connection quartz glass system to prevent oxidation of the foils,
- said solder glass being, except for trace contaminants, free from Na.sub.2 O, and consisting essentially of the following main components:
- SiO.sub.2 :
- 60-70%
- A1.sub.2 O.sub.3 :
- 3-20%
- K.sub.2 O :
- 12-18%,
- all percentages by weight.
Dependencies are inferred from the claim text.