Patent US2521073A successfully refreshed from Google Patents.
US2521073A
Expired / Lapsed
US
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Cement for lightweight concrete and method of making
Assignee: Universal Atlas Cement Co
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Filing: 1948-03-17
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Granted: 1950-09-05
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Expires: 1968-03-17
Abstract
No abstract record available.
Inventors
- 👤 Norman C Ludwig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:51
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/04; Y; Y10; Y10S; Y10S106/00; Y10S106/03
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
54 words
IN A METHOD OF MAKING POROUS CONCRETE, THE STEPS INCLUDING ADDING TO PORTLAND CEMENT FROM 1 TO 2% WHEAT FLOUR BY WEIGHT AND FROM .0625% TO .40% BY WEIGHT OF THE NEUTRALIZED FRACTION OF THE COAL-TAR-HYDROCARBON EXTRACT OF PINE WOOD WHICH IS INSOLUBLE IN PETROLEUM HYDROCARBONS AND ADDING WATER TO PRODUCE A WET MIX.
Claim 2
Dependent Claim
54 words
IN A METHOD OF MAKING POROUS CONCRETE, THE STEPS INCLUDING ADDING TO PORTLAND CEMENT FROM 1 TO 2% WHEAT FLOUR BY WEIGHT AND FROM .0625% TO .40% BY WEIGHT OF THE NEUTRALIZED FRACTION OF THE COAL-TAR-HYDROCARBON EXTRACT OF PINE WOOD WHICH IS INSOLUBLE IN PETROLEUM HYDROCARBONS AND ADDING WATER TO PRODUCE A WET MIX.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-09-04 | 1954-03-06 | 1954-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-09-04 | 1958-03-06 | 1958-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-09-04 | 1962-03-06 | 1962-09-05 | $7700.00 | Window Closed / Lapsed |