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Patent US3966440A successfully refreshed from Google Patents.
US3966440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Colorimetric vinyl chloride indicator
Assignee: Catalyst Research Corp
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Filing: 1975-06-03
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Granted: 1976-06-29
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Expires: 1995-06-03
Abstract
Abstract A colorimetric indicator for use in indicating the impending exhaustion of a vinyl organo filtering device. The colorimetric indicator material consists of activated alumina impregnated with between 0.5 to 5.0% by weight potassium permanganate and is positioned immediately behind a window in a canister or cartridge used in filtering vinyl organo materials.
Inventors
- 👤 Charles Clifton Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:53
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; Y; Y10; Y10S; Y10S55/00; Y10S55/33; Y10S55/34; Y10T; Y10T436/00; Y10T436/19; Y10T436/196666
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
104 words
In a canister for removing airborne vinyl organo material from the atmosphere having an inlet and an outlet port and an inner chamber substantially filled with an active particulate material positioned between said inlet and outlet port for removing said airborne vinyl organo material and including an indicator window positioned for viewing into said inner chamber and adjacent to said outlet port, the improvement comprising a solid vinyl organo colorimetric indicating material positioned immediately behind said indicator window and extending into said active material, said vinyl organo colorimetric indicating material consisting of activated alumina impregnated with between 0.5 and 5.0% by weight potassium permanganate.
Claim 2
Dependent Claim
104 words
In a canister for removing airborne vinyl organo material from the atmosphere having an inlet and an outlet port and an inner chamber substantially filled with an active particulate material positioned between said inlet and outlet port for removing said airborne vinyl organo material and including an indicator window positioned for viewing into said inner chamber and adjacent to said outlet port, the improvement comprising a solid vinyl organo colorimetric indicating material positioned immediately behind said indicator window and extending into said active material, said vinyl organo colorimetric indicating material consisting of activated alumina impregnated with between 0.5 and 5.0% by weight potassium permanganate.
Claim 3
Dependent Claim
22 words
In a canister as set forth in claim 1 wherein said potassium permanganate is present in an amount of 3.0% by weight.
Claim 4
Dependent Claim
21 words
In a canister as set forth in claim 1 wherein said colorimetric indicating material is contained within a gas permeable container.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-29 | 1979-12-29 | 1980-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-29 | 1983-12-29 | 1984-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-29 | 1987-12-29 | 1988-06-29 | $7700.00 | Window Closed / Lapsed |