US3087408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Factory-built chimney
Assignee: DURA VENT CORP
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Filing: 1960-10-24
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Granted: 1963-04-30
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Expires: 1980-10-24
Abstract
No abstract record available.
Inventors
- 👤 John H Carr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:51
CPC Classifications
F; F23; F23J; F23J13/00; F23J13/02; F23J13/025; F23L; F23L17/00; F23L17/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A PIPE SECTION ADAPTED FOR USE IN A PREFABRICATED, FACTORY BUILT CHIMNEY COMPRISING AN INNER PIPE AND AN OUTER PIPE CONCENTRIC THEREWITH, FLAT PERFORATED RINGS AT EACH END OF SAID PIPE SECTION HOLDING THE INNER AND OUTER PIPES CONCENTRIC, AT LEAST ONE ADDITIONAL PIPE DISPOSED BETWEEN SAID INNER AND OUTER PIPES, SAID ADDITIONAL PIPE BEING CONCENTRIC THEREWITH, FASTENING MEANS ON EACH OF SAID RINGS TO HOLD SAID ADDITIONAL PIPE IN SPACED RELATIONSHIP TO THE INNER AND OUTER PIPES, ONE OF SAID RINGS FORMING A MALE CONNECTION AT ONE END OF SAID PIPE SECTION AND AT THE OPPOSITE END OF SAID PIPE SECTION A FEMALE CONNECTION FORMED BY THE OUTER PIPE.
Claim 2
Dependent Claim
110 words
A PIPE SECTION ADAPTED FOR USE IN A PREFABRICATED, FACTORY BUILT CHIMNEY COMPRISING AN INNER PIPE AND AN OUTER PIPE CONCENTRIC THEREWITH, FLAT PERFORATED RINGS AT EACH END OF SAID PIPE SECTION HOLDING THE INNER AND OUTER PIPES CONCENTRIC, AT LEAST ONE ADDITIONAL PIPE DISPOSED BETWEEN SAID INNER AND OUTER PIPES, SAID ADDITIONAL PIPE BEING CONCENTRIC THEREWITH, FASTENING MEANS ON EACH OF SAID RINGS TO HOLD SAID ADDITIONAL PIPE IN SPACED RELATIONSHIP TO THE INNER AND OUTER PIPES, ONE OF SAID RINGS FORMING A MALE CONNECTION AT ONE END OF SAID PIPE SECTION AND AT THE OPPOSITE END OF SAID PIPE SECTION A FEMALE CONNECTION FORMED BY THE OUTER PIPE.
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) | 1966-04-29 | 1966-10-29 | 1967-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-04-29 | 1970-10-29 | 1971-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-04-29 | 1974-10-29 | 1975-04-30 | $7700.00 | Window Closed / Lapsed |