Patent US3849690A successfully refreshed from Google Patents.
US3849690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flash tube having improved cathode
Assignee: GTE Sylvania Inc
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Filing: 1973-11-05
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Granted: 1974-11-19
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Expires: 1993-11-05
Abstract
Abstract An injection-triggered xenon flash tube having an elongated glass envelope with anode and cathode electrodes sealed in the ends thereof. The cathode comprises a pressed and sintered pellet of powdered tantalum and barium aluminate with a 100 percent pitched tungsten coil wound about the cylindrical sidewall of the pellet.
Inventors
- 👤 R Cosco
- 👤 J Pappas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:39
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/30; H01J61/00; H01J61/02; H01J61/04; H01J61/06; H01J61/067
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
107 words
AN ELECTRIC DISCHARGE LAMP COMPRISING: AN HERMETICALLY SEALED, LIGHT TRANSMITTING ENVELOPE; A RARE GAS IN SAID ENVELOPE; AND A PAIR OF ELECTRODES IN SAID ENVELOPE, ONE DISPOSED AT EACH END THEREOF, BETWEEN WHICH AN ARC DISCHARGE PATH IS DEFINED DURING OPERATION OF SAID LAMP; AT LEAST ONE OF SAID ELECTRODES COMPRISING A PRESSED AND SINTER PELLET HAVING A SUBSTANTIALLY CYLINDRICAL SIDEWALL AND COMPOSED OF A SUBSTATIALLY HOMOGENEOUS MIXTURE INCLUDING A POWDERED REFRACTORY METAL AND AN ELECTRON-EMITTING MATERIAL SAID CYLINDRICAL PELLET BEING AXIALLY ALIGNED WITH SAID ARC DISCHARGE PATH, AND A 100 PERCENT PITCHED COIL OF REFRACTORY METAL WIRE SECURELY WOUND ABOUT THE CYLINDRICAL SIDEWALL OF SAID PELLET.
Claim 2
Dependent Claim
107 words
AN ELECTRIC DISCHARGE LAMP COMPRISING: AN HERMETICALLY SEALED, LIGHT TRANSMITTING ENVELOPE; A RARE GAS IN SAID ENVELOPE; AND A PAIR OF ELECTRODES IN SAID ENVELOPE, ONE DISPOSED AT EACH END THEREOF, BETWEEN WHICH AN ARC DISCHARGE PATH IS DEFINED DURING OPERATION OF SAID LAMP; AT LEAST ONE OF SAID ELECTRODES COMPRISING A PRESSED AND SINTER PELLET HAVING A SUBSTANTIALLY CYLINDRICAL SIDEWALL AND COMPOSED OF A SUBSTATIALLY HOMOGENEOUS MIXTURE INCLUDING A POWDERED REFRACTORY METAL AND AN ELECTRON-EMITTING MATERIAL SAID CYLINDRICAL PELLET BEING AXIALLY ALIGNED WITH SAID ARC DISCHARGE PATH, AND A 100 PERCENT PITCHED COIL OF REFRACTORY METAL WIRE SECURELY WOUND ABOUT THE CYLINDRICAL SIDEWALL OF SAID PELLET.
Claim 3
Dependent Claim
18 words
A lamp according to claim 1 wherein the electron-emitting material in said pellet comprises an alkaline earth compound.
Claim 4
Dependent Claim
18 words
A lamp according to claim 2 wherein said coil about the pellet is a winding of tungsten wire.
Claim 5
Dependent Claim
23 words
A lamp according to claim 3 wherein the composition of said pellet comprises a substantially homogeneous mixture of powdered tantalum and barium aluminate.
Claim 6
Dependent Claim
50 words
A lamp according to claim 4 wherein the composition of said pellet prior to sintering consists essentially of from about 75 percent to 95 percent by weight of tantalum, about 5 percent to 25 percent by weight of Ba3Al2O6 and about 0 percent to 1 percent by weight of nickel.
Claim 7
Dependent Claim
36 words
The device of claim 1 wherein said lamp is an injection-triggered flash tube, said rare gas is xenon, and the electrode comprising said pellet with said coil wound thereabout is the cathode of said flash tube.
Claim 8
Dependent Claim
36 words
The flash tube of claim 6 wherein the electron-emitting material in said pellet comprises an alkaline earth compound, and said coil of refractory metal wire is wound about substantially the entire cylindrical sidewall of said pellet.
Claim 9
Dependent Claim
58 words
The flash tube of claim 7 wherein said coil is wound of tungsten wire, said pellet has a tapered end pointing toward the inside of said flash tube and providing one terminus of said arc discharge path, the composition of said pellet comprises a substantially homogeneous mixture of powdered tantalum and barium aluminate, and said cathOde is activated.
References Cited (Backward Citations)
US3463958A
Cited
US3753028A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |