Patent US4821473A successfully refreshed from Google Patents.
US4821473A
Expired / Lapsed
US
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Chimney by-pass
Assignee: Individual
•
Filing: 1988-03-31
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Granted: 1989-04-18
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Expires: 2008-03-31
Abstract
Abstract A chimney by-pass is disclosed for use with a main chimney. In case of a chimney fire, a movable damper closes off the main chimney, substantially reducing the severity of the chimney fire. The movable damper also opens an auxiliary chimney, allowing smoke to exit, uninterrupted through the auxiliary chimney, and may include a fan to assist the exit of smoke into the atmosphere. The movable damper may be actuated manually or automatically in case of a chimney fire.
Inventors
- 👤 Ernest E. Cowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:37
CPC Classifications
A; A62; A62C; A62C4/00; A62C4/04; E; E04; E04F; E04F17/00; E04F17/02; F; F23; F23J; F23J11/00; F23L; F23L11/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
39 words
A chimney by-pass for use with a main chimney to reduce chimney fires and handle smoke, comprising; an auxiliary chimney; a movable damper; means for moving said movable damper, thereby closing said main chimney and opening said auxiliary chimney.
Claim 2
Dependent Claim
39 words
A chimney by-pass for use with a main chimney to reduce chimney fires and handle smoke, comprising; an auxiliary chimney; a movable damper; means for moving said movable damper, thereby closing said main chimney and opening said auxiliary chimney.
Claim 3
Dependent Claim
47 words
The chimney by-pass of claim 1, wherein; said auxiliary chimney includes one end defining a first aperture into said main chimney, whereby smoke may exit said main chimney through said first aperture into said auxiliary chimney; and said auxiliary chimney including another end open to the atmosphere.
Claim 4
Dependent Claim
46 words
The chimney by-pass of claim 1, wherein; said movable damper is shiftable between two operational positions, whereby in a first operational position said movable damper closes said auxiliary chimney and a second operational position said movable damper closes said main chimney and opens said auxiliary chimney.
Claim 5
Dependent Claim
57 words
The chimney by-pass of claim 1, wherein: said auxiliary chimney includes a container having one side defining a first aperture into said main chimney, said container having another side defining a second aperture open to the atmosphere; and a fan disposed in said second aperture of said container to urge smoke within said container into the atmosphere.
Claim 6
Dependent Claim
27 words
The chimney by-pass of claim 1, including; a layer of insulating material attached to said movable damper to protect said movable damper from heat and smoke buildup.
Claim 7
Dependent Claim
26 words
The chimney by-pass of claim 1, including; means for sensing a fire in said main chimney; and indicating means operable upon actuation of said sensing means.
Claim 8
Dependent Claim
22 words
The chimney by-pass of claim 6, including; automatic means for actuating said movable damper in response to actuation of said sensing means.
References Cited (Backward Citations)
US538976A
Cited
US1439925A
Cited
US1480488A
Cited
FR524029A
Cited
US2713301A
Cited
FR2499215A1
Cited
US4487137A
Cited
US4434784A
Cited
US4519458A
Cited
US4646847A
Cited
US4616457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-17 | 1992-10-17 | 1993-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-17 | 1996-10-17 | 1997-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-17 | 2000-10-17 | 2001-04-18 | $7700.00 | Window Closed / Lapsed |