US3768957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flash bulb
Assignee: US Philips Corp
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Filing: 1971-09-21
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Granted: 1973-10-30
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Expires: 1991-09-21
Abstract
Abstract A flash bulb of the combustible type in which at least the current conductors within the envelope are surrounded by a separate tubular body which shields the envelope walls from heat and ignition and shields the current conductors from the wire filling.
Inventors
- 👤 Der Tas J Van
- 👤 C Eduard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:44
CPC Classifications
F; F21; F21K; F21K5/00; F21K5/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
180 words
A flashlamp comprising a tubular, transparent envelope having a longitudinal axis, said envelope being closed at one end and secured to a base section at the other end, lead-in wires extending through said base section into said envelope, a bead of non-conductive material secured between said lead-in wires within said envelope, an ignition mass arranged in cooperative relationship with the ends of said lead-in wires positioned within said envelope, an oxidizable metal within said envelope, an oxidizing gas within said envelope, said ignition mass cooperating with said oxidizable metal and said oxidizing gas to produce intense actinic rays from said flashlamp, and a tubular non-combustible open ended shield secured at one end to said base section within said envelope, said shield having a longitudinal axis of said envelope and generally continuous walls surrounding said ignition mass between said ignition mass and said envelope for preventing said ignition mass from spreading burning particles in directions perpendicular to the longitudinal axis of said envelope that can strike and break the envelope, said oxidation metal being located between said envelope and said shield.
Claim 2
Dependent Claim
180 words
A flashlamp comprising a tubular, transparent envelope having a longitudinal axis, said envelope being closed at one end and secured to a base section at the other end, lead-in wires extending through said base section into said envelope, a bead of non-conductive material secured between said lead-in wires within said envelope, an ignition mass arranged in cooperative relationship with the ends of said lead-in wires positioned within said envelope, an oxidizable metal within said envelope, an oxidizing gas within said envelope, said ignition mass cooperating with said oxidizable metal and said oxidizing gas to produce intense actinic rays from said flashlamp, and a tubular non-combustible open ended shield secured at one end to said base section within said envelope, said shield having a longitudinal axis of said envelope and generally continuous walls surrounding said ignition mass between said ignition mass and said envelope for preventing said ignition mass from spreading burning particles in directions perpendicular to the longitudinal axis of said envelope that can strike and break the envelope, said oxidation metal being located between said envelope and said shield.
Claim 3
Dependent Claim
35 words
A flashlamp as claimed in claim 1 wherein said tubular non-combustible shield surrounding said ignition mass shields said ignition mass for a distance at least equal to the internal diameter of said tUbular non-combustible shield.
Claim 4
Dependent Claim
14 words
A flashlamp as claimed in claim 1 wherein said tubular non-combustible shield comprises glass.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |