Photoflash lamp construction and method of making same
US4270897A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1978 |
| Grant date | Jun 2, 1981 |
| Priority date | — |
| Expiry date | Dec 21, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21K5/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A high-voltage type photoflash lamp filled with a filamentary combustible material and oxygen and having an ignition structure including a pair of spaced-apart lead-in wires sealed in one end of the glass envelope of the lamp and encapsulated within an interior protruding portion of the envelope glass. The termination of each of the lead-in wires within the envelope is bare of sealing glass and substantially flush with the surrounding glass surface, and a coating of primer material about the inner end of the protruding portion of glass within the envelope covers and bridges the bare terminations of the lead-in wires. Also disclosed is a method of making a lamp including the steps of heating one end of a length of glass tubing to seal it closed, pushing a pair of spaced-apart metal lead-in wires through the heated, closed end of the glass tubing whereby the heated glass thereat is stretched and sealed over the wires to provide a protruding portion of glass within the tubing which encapsulates the termination of the lead-in wires, selectively removing only the glass covering the terminations of the lead-in wires to expose the bare metal thereof, applying a coating of primer material …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.