Patent US3112243A successfully refreshed from Google Patents.
US3112243A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for making hardboard
Assignee: Superwood Corp
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Filing: 1961-09-18
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Granted: 1963-11-26
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Expires: 1981-09-18
Abstract
No abstract record available.
Inventors
- 👤 Lennart N Egerstrand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:31
CPC Classifications
B; B30; B30B; B30B15/00; B30B15/06; B30B15/062; D; D21; D21J; D21J1/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
96 words
THE METHOD OF MANUFACTURING HARDBOARD CONSISTING IN COMPRESSING A LAYER OF WET PULP WHILE SIMULTANEOUSLY APPLYING HEAT THERETO, AND PRIOR THERETO INSERTING A PERFORATED PLATE HAVING A SUITABLE NUMBER AND SIZE AND ARRANGEMENT OF PERFORATIONS THEREIN OF A COMBINED AREA WITHIN THE RANGE OF ABOUT 4% TO ABOUT 17% OF THE TOTAL AREA OF THE PLATE AGAINST THE LAYER OF WET PULP FOR CONTROLLABLY RESTRICTING UNIFORMLY ACROSS THE LAYER THE DRAINAGE OF WATER THEREFROM WHILE THE LAYER IS SO COMPRESSED AND HEATED, THUS PROVIDING A BOARD OF UNIFORM DENSITY AND STRENGTH THROUGHOUT THE ENTIRE AREA THEREOF.
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) | 1966-11-25 | 1967-05-27 | 1967-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-11-25 | 1971-05-27 | 1971-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-11-25 | 1975-05-27 | 1975-11-26 | $7700.00 | Window Closed / Lapsed |