Patent US2044345A successfully refreshed from Google Patents.
Patent US3123133A successfully refreshed from Google Patents.
US3123133A
Expired / Lapsed
US
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Duplex tubes
Assignee: —
•
Filing: —
•
Granted: 1964-03-03
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Expires: 1981-03-03
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:09
CPC Classifications
F; F28; F28F; F28F21/00; F28F21/08; F22; F22D; F22D1/00; F22D1/02; F28F1/00; F28F1/003; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49885; Y10T29/49908; Y10T29/49925; Y10T29/49927; Y10T29/49929
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
60 words
A DUPLEX TUBE INCLUDING TWO TUBES RESPECTIVELY OF DIFFERING GAS PERMEABILITIES AND TELESCOPED TOGETHER WITH THEIR OPPOSED SURFACES SEPARABLY PRESSED TOGETHER AND HAVING END PORTIONS FOR RADIAL EXPANSION IN TUBE SHEET HOLES, AND A GAS-PERMEABLE LAYER LOCATED BETWEEN SAID SURFACES FOR THE EXTENT OF AT LEAST ONE OF SAID PORTIONS, SAID LAYER COMPRISING A SUBSTANTIALLY UNIFORM DISTRIBUTION OF HARD PARTICLES.
Claim 2
Dependent Claim
60 words
A DUPLEX TUBE INCLUDING TWO TUBES RESPECTIVELY OF DIFFERING GAS PERMEABILITIES AND TELESCOPED TOGETHER WITH THEIR OPPOSED SURFACES SEPARABLY PRESSED TOGETHER AND HAVING END PORTIONS FOR RADIAL EXPANSION IN TUBE SHEET HOLES, AND A GAS-PERMEABLE LAYER LOCATED BETWEEN SAID SURFACES FOR THE EXTENT OF AT LEAST ONE OF SAID PORTIONS, SAID LAYER COMPRISING A SUBSTANTIALLY UNIFORM DISTRIBUTION OF HARD PARTICLES.
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) | 1967-03-03 | 1967-09-02 | 1968-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-03-03 | 1971-09-02 | 1972-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-03-03 | 1975-09-02 | 1976-03-03 | $7700.00 | Window Closed / Lapsed |