US3721515A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combustion flash bulb
Assignee: US Philips Corp
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Filing: 1971-11-02
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Granted: 1973-03-20
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Expires: 1991-11-02
Abstract
Abstract A combustion flash bulb ignited by means of a piezo-electric ignition in which, to protect the wall of the envelope, a separate tubular inner envelope is arranged in the envelope, said inner envelope being open at its end facing the lamp base and comprising the metal wool to be burned. In order to attenuate the shock wave occurring during the combustion in the inner envelope, said inner envelope comprises opposite to the open tube end a narrowed end in which an aperture is provided. The inner envelope is thin-walled and manufactured from a soft glass.
Inventors
- 👤 Der Tas J Van
- 👤 C Meulemans
- 👤 A Boekkooi
- 👤 A Hurx
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:12
CPC Classifications
F; F21; F21K; F21K5/00; F21K5/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
A combustion flash bulb which comprises a hermetically sealed light-pervious outer envelope and a tubular inner envelope which is open at its end facing the lamp base, the space in the inner envelope communicating with the space in the outer envelope, a filling of an oxidizable metal and an ignition mechanism being present in the inner envelope, an oxygen-containing atmosphere prevailing inside the outer envelope, wherein the inner envelope, at its narrowed end remote from the lamp base, includes an aperture the cross-section of which calculated at right angles to the longitudinal axis of the lamp, is at most 30 percent of the surface bounded by the inner wall of the inner envelope.
Claim 2
Dependent Claim
113 words
A combustion flash bulb which comprises a hermetically sealed light-pervious outer envelope and a tubular inner envelope which is open at its end facing the lamp base, the space in the inner envelope communicating with the space in the outer envelope, a filling of an oxidizable metal and an ignition mechanism being present in the inner envelope, an oxygen-containing atmosphere prevailing inside the outer envelope, wherein the inner envelope, at its narrowed end remote from the lamp base, includes an aperture the cross-section of which calculated at right angles to the longitudinal axis of the lamp, is at most 30 percent of the surface bounded by the inner wall of the inner envelope.
Claim 3
Dependent Claim
66 words
A combustion flash bulb as claimed in claim 1 of which the length is at least 3 times the inside diameter and in which the ignition mechanism is present near the lamp base, wherein the inner envelope is movable in the outer envelope in the axial direction, the ignition mechanism being surrounded by the inner envelope in the two extreme axial positions of the inner envelope.
Claim 4
Dependent Claim
32 words
A combustion flash bulb as claimed in claim 2, wherein the clearance between the side walls facing each other of the inner envelope and the outer envelope is at most 0.5 mm.
Claim 5
Dependent Claim
35 words
A combustion flash bulb as claimed in claim 1, wherein the oxidizable metal present in the inner envelope is kept spaced apart from the ignition mechanism present near the lamp base by a suitable adhesive.
Claim 6
Dependent Claim
20 words
A combustion flash bulb as claimed in claim 1, wherein the inner envelope is manufactured from a blue-colored vitreous mass.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |