Patent US2953379A successfully refreshed from Google Patents.
Patent US3139328A successfully refreshed from Google Patents.
US3139328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Indicator paper
Assignee: Sunoco Inc
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Filing: 1960-07-21
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Granted: 1964-06-30
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Expires: 1980-07-21
Abstract
No abstract record available.
Inventors
- 👤 Lawrence N Jacob
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:06
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/221
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
127 words
PAPER FOR INDICATING PH WHICH COMPRISES PAPER IMPREGANATED WITH A PLURALITY OF INDICATORS, EACH IN A DIFFERENT SECTION OF THE PAPER AND EACH ADAPTED TO UNDERGO A COLOR CHANGE FROM COLORLESS TO COLORED IN A DIFFERENT PART OF THE PH RANGE, THE INDICATORS BEING ARRANGED IN ORDER OF INCREASING PH AT WHICH SUCH CHANGE TAKES PLACE, WHEREBY UPON EXPOSURE OF THE PAPER TO A MEDIUM HAVING A GIVEN PH, THE PAPER HAS ONE PORTION COMPOSED OF SECTIONS CONTAINING THE INDICATORS WHICH CHANGE COLOR AT A PH BELOW SAID GIVEN PH, AND ANOTHER PORTION COMPOSED OF SECTIONS CONTAINING THE INDICATORS WHICH CHANGE COLOR AT A PH ABOVE SAID GIVEN PH, THE LOCATION OF THE VISIBLE BOUNDARY BETWEEN THE PORTIONS OF THE PAPER INDICATING THE PH OF THE MEDIUM.
Claim 2
Dependent Claim
127 words
PAPER FOR INDICATING PH WHICH COMPRISES PAPER IMPREGANATED WITH A PLURALITY OF INDICATORS, EACH IN A DIFFERENT SECTION OF THE PAPER AND EACH ADAPTED TO UNDERGO A COLOR CHANGE FROM COLORLESS TO COLORED IN A DIFFERENT PART OF THE PH RANGE, THE INDICATORS BEING ARRANGED IN ORDER OF INCREASING PH AT WHICH SUCH CHANGE TAKES PLACE, WHEREBY UPON EXPOSURE OF THE PAPER TO A MEDIUM HAVING A GIVEN PH, THE PAPER HAS ONE PORTION COMPOSED OF SECTIONS CONTAINING THE INDICATORS WHICH CHANGE COLOR AT A PH BELOW SAID GIVEN PH, AND ANOTHER PORTION COMPOSED OF SECTIONS CONTAINING THE INDICATORS WHICH CHANGE COLOR AT A PH ABOVE SAID GIVEN PH, THE LOCATION OF THE VISIBLE BOUNDARY BETWEEN THE PORTIONS OF THE PAPER INDICATING THE PH OF THE MEDIUM.
References Cited (Backward Citations)
US2167304A
Cited
US2249867A
Cited
US2464155A
Cited
US2643230A
Cited
US2738257A
Cited
US3006736A
Cited
US3011874A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-06-30 | 1967-12-30 | 1968-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-06-30 | 1971-12-30 | 1972-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-06-30 | 1975-12-30 | 1976-06-30 | $7700.00 | Window Closed / Lapsed |