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US3712701A Expired / Lapsed US ⏱️ 0.0 years remaining

Electric incandescent lamps

Assignee: British Lighting Industries Ltd
•
Filing: 1971-08-27
•
Granted: 1973-01-23
•
Expires: 1991-08-27
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Abstract

Abstract A tungsten-halogen cycle electric incandescent lamp has a fill including a phosphonitrilic halide. Mixtures of more than one of the halides may be employed. The halide can be introduced into the lamp envelope in solution, the solvent being evaporated thereafter to leave the halide as residue.

Inventors

  • 👤 R Johnston
  • 👤 J Rees

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 17:08
CPC Classifications
H; H01; H01K; H01K1/00; H01K1/50; Y; Y02; Y02B; Y02B20/00

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 20 words
A method according to claim 1 in which said solution contains a mixture of (PNBr2)3 and (PNBr2)4 as said halide.
Claim 2
Dependent Claim 21 words
A method according to claim 2 in which said solution contains 0.15 g of said mixture per 100 c.c.s of solution.
Claim 3
Dependent Claim 12 words
A method according to claim 3 in which said solvent is benzene.
Claim 4
Dependent Claim 30 words
A method according to claim 1 in which said solution contains a mixture of (PNC lambda 2)4, (PNC lambda 2)5, (PNC lambda 2)6 and (PNC lambda 2)7 as said halide.
Claim 5
Dependent Claim 21 words
A method according to claim 5 in which said solution contains 0.05 g of said mixture per 100 c.c.s of solution.
Claim 6
Dependent Claim 13 words
A method according to claim 6 in which said solvent is petroleum ether.

References Cited (Backward Citations)

CA763062A Cited
US1246118A Cited
US1944825A Cited
US3465193A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-01-23 1976-07-24 1977-01-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-01-23 1980-07-24 1981-01-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-01-23 1984-07-24 1985-01-23 $7700.00 Window Closed / Lapsed

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