Patent US3804769A successfully refreshed from Google Patents.
US4486743A
Expired / Lapsed
US
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Creosote buildup detector and annunciator
Assignee: Honeywell Inc
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Filing: 1982-03-05
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Granted: 1984-12-04
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Expires: 2002-03-05
Abstract
Abstract A creosote buildup detector utilizes a change in temperature between two sensors. The temperature between the two sensors changes as the creosote builds up. This change in temperature is established by providing an electric heater to heat one of the sensor supports. A temperature comparator senses the change in relative temperatures between the two sensors and annunciates when a sufficient creosote buildup has occurred to indicate that cleaning the chimney is necessary.
Inventors
- 👤 Peter K. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:12
CPC Classifications
G; G08; G08B; G08B21/00; G08B21/18; G08B21/182
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
166 words
A creosote buildup detector adapted to be mounted in a chimney to detect an unsafe buildup of creosote in said chimney and to annunciate that condition, including: temperature sensing means including first temperature sensor and heat generating means, and a second temperature sensor spaced apart from said first temperature sensor and heat generating means; mounting means including a pair of insulating mounting members with one each of said mounting members to mount said temperature sensor and heat generating means, and said second temperature sensor adjacent each other in said chimney; said heat generating means raising the temperature of said temperature sensors and heat generating means; temperature comparator means connected to said two temperature sensors to compare a relative temperature difference between said sensors caused by said heat generating means; and annunciator means connected to said comparator means to respond to an excess of a set level of temperature difference detected between said temperature sensors to indicate the unsafe buildup of creosote at said pair temperature sensors.
Claim 2
Dependent Claim
166 words
A creosote buildup detector adapted to be mounted in a chimney to detect an unsafe buildup of creosote in said chimney and to annunciate that condition, including: temperature sensing means including first temperature sensor and heat generating means, and a second temperature sensor spaced apart from said first temperature sensor and heat generating means; mounting means including a pair of insulating mounting members with one each of said mounting members to mount said temperature sensor and heat generating means, and said second temperature sensor adjacent each other in said chimney; said heat generating means raising the temperature of said temperature sensors and heat generating means; temperature comparator means connected to said two temperature sensors to compare a relative temperature difference between said sensors caused by said heat generating means; and annunciator means connected to said comparator means to respond to an excess of a set level of temperature difference detected between said temperature sensors to indicate the unsafe buildup of creosote at said pair temperature sensors.
Claim 3
Dependent Claim
30 words
A creosote buildup detector as described in claim 1 wherein said first temperature sensor and heat generating means includes a separate first temperature sensor and a seperate heat generating means.
Claim 4
Dependent Claim
26 words
A creosote buildup detector as described in claim 2 wherein each of said temperature sensors includes a temperature sensitive element mounted within a heat conducting pod.
Claim 5
Dependent Claim
51 words
A creosote buildup detector as described in claim 3 wherein each of said mounting members is a tubular insulating support with said heat conducting pod mounted upon an end of said support; and said tubular support enclosing and protecting circuit means connecting said temperature sensitive element to said temperature comparator means.
Claim 6
Dependent Claim
45 words
A creosote buildup detector as described in claim 4 wherein said heater means mounts upon said first of said mounting members and is insulated from said creosote buildup; and said heater means being of insufficient power to burn off said creosote buildup as it occurs.
Claim 7
Dependent Claim
17 words
A creosote buildup detector as described in claim 5 wherein said heat conducting pods are metallic spheres.
Claim 8
Dependent Claim
31 words
A creosote buildup detector as described in claim 2 wherein said creosote buildup detector is mounted upon a panel that can be readily removed from said chimney for cleaning and inspection.
Claim 9
Dependent Claim
33 words
A creosote buildup detector as described in claim 2 wherein said creosote building detector is mounted in a recess in said chimney to protect said creosote buildup detector upon said chimney being cleaned.
Claim 10
Dependent Claim
26 words
A creosote buildup detector as described in claim 8 wherein each of said temperature sensors includes a temperature sensitive element mounted within a heat conducting pod.
Claim 11
Dependent Claim
51 words
A creosote buildup detector as described in claim 9 wherein each of said mounting members is a tubular insulating support with said heat conducting pod mounted upon an end of said support; and said tubular support enclosing and protecting circuit means connecting said temperature sensitive elements to said temperature comparator means.
Claim 12
Dependent Claim
45 words
A creosote buildup detector as described in claim 10 wherein said heater means mounts upon said first of said insulating members and is insulated from said creosote buildup; and said heater means being of insufficient power to burn off said creosote buildup as it occurs.
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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) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |