US2687968A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reflex-reflector lens elements
Assignee: 3M Co
•
Filing: 1950-07-26
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Granted: 1954-08-31
•
Expires: 1970-07-26
Abstract
No abstract record available.
Inventors
- 👤 Warren R Beck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:50
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/089
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
128 words
CLEAR, TRANSPARENT, SUBSTANTIALLY COLORLESS, WEATHER-RESISTANT, STRONG AND TOUGH SMALL GLASS BEADS OF SPHERICLES HAVING A REFRACTIVE INDEX OF ABOUT 1.6 AND SUITABLE FOR INCORPORATION AS REFLEXRELECTIVE LENS ELEMENTS IN PAINTED HIGHWAY CENTERLINES, AND HAVING A COMPOSITION IN PERCENT BY WEIGHT, AS CALCULATED FROM THE BATCH, ESSENTIALLY AS FOLLOWS: SAID COMPOSITION TOTALING SUBSTANTIALLY 100 PERCENT; WHEREIN THE TOTAL OF NA2O, F2, AND B2O3 IS ABOUT 10-24; SUBJECT TO THE FURTHER CONDITION THAT THE TOTAL OF NA2O AND F2 MUST BE AT LEAST EQUAL TO ABOUT ONE-TENTH OF THE TOTAL OF SIO2 AND AL2O3 WHEN THE TOTAL OF SIO2 AND AL2O3 IS AT LEAST ABOUT 40 PERCENT OF THE GLASS COMPOSITION; SAID OTHER COMPONENTS CONSISTING OF AT LEAST ONE OF THE OXIDES ZNO, PBO, ZRO2, BAO, SRO, LI2O, AND P2O5.
References Cited (Backward Citations)
US2010836A
Cited
US2610922A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-08-30 | 1958-03-01 | 1958-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-08-30 | 1962-03-01 | 1962-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-08-30 | 1966-03-01 | 1966-08-31 | $7700.00 | Window Closed / Lapsed |