US3971344A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety device for instant water heater
Assignee: Saunier Duval SA
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Filing: 1975-01-08
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Granted: 1976-07-27
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Expires: 1995-01-08
Abstract
Abstract The safety device disclosed herein is adapted for use with low power gas burning water heaters which are unvented. In order to limit the duty cycle of the heater, a thermal mass having a preselected thermal inertia is heated from the burner through a probe of limited heat conductivity so that the temperature of the thermal mass rises relatively slowly during operation of the heater and cools relatively slowly in the intervals between operation. If the thermal mass reaches a predetermined threshold temperature, the heater is turned off or sharply throttled back so as to limit the emission of combustion products into the atmosphere.
Inventors
- 👤 Jacques Gouyou-Beauchamps
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:06
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/02; F23N5/022; F23N2223/00; F23N2223/12; F23N2225/00; F23N2225/08; F23N2225/10; F23N2225/16; F23N5/10; F23N5/24
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
151 words
A safety device for a gas water heater of the type in which combustion products from a gas burner are vented into the room in which the heater is installed, said device comprising: a thermal mass having a preselected thermal capacity, said mass being positioned away from the heating zone of said heater: a probe of preselected thermal conductivity extending from said mass into the heating zone of said heater, thereby to cause the temperature of said mass to increase at an essentially predetermined rate during operation of said burner; the cooling of said mass occuring at an essentially predetermined rate between operations of said burner; selectively operable throttling means for said burner; and a temperature sensing means which is responsive to the temperature of said mass and which is interconnected with said throttling means for substantially throttling said burner when the temperature of said mass reaches a preselected threshold temperature.
Claim 2
Dependent Claim
151 words
A safety device for a gas water heater of the type in which combustion products from a gas burner are vented into the room in which the heater is installed, said device comprising: a thermal mass having a preselected thermal capacity, said mass being positioned away from the heating zone of said heater: a probe of preselected thermal conductivity extending from said mass into the heating zone of said heater, thereby to cause the temperature of said mass to increase at an essentially predetermined rate during operation of said burner; the cooling of said mass occuring at an essentially predetermined rate between operations of said burner; selectively operable throttling means for said burner; and a temperature sensing means which is responsive to the temperature of said mass and which is interconnected with said throttling means for substantially throttling said burner when the temperature of said mass reaches a preselected threshold temperature.
Claim 3
Dependent Claim
20 words
A safety device as set forth in claim 1 wherein said sensing means is a thermoswitch contacting said thermal mass.
Claim 4
Dependent Claim
19 words
A safety device as set forth in claim 2 wherein said throttling means is an electrically operated safety valve.
Claim 5
Dependent Claim
35 words
A safety device as set forth in claim 3 wherein said burner is provided with a pilot light and a thermocouple safety switching device for de-energizing said safety valve when said pilot light is extinguished.
Claim 6
Dependent Claim
25 words
A safety device as set forth in claim 4 wherein said thermoswitch and said thermocouple safety switching device are connected in series with said valve.
Claim 7
Dependent Claim
40 words
A safety device as set forth in claim 1 wherein said sensing means is a thermo-mechanical device, wherein said throttling means is a valve in the gas supply to said burner, and wherein said sensing means directly operates said valve.
Claim 8
Dependent Claim
27 words
A safety device as set forth in claim 6 wherein said valve completely shuts off the gas to said burner when said mass reaches said threshold temperature.
Claim 9
Dependent Claim
38 words
A safety device as set forth in claim 6 wherein said valve operates to substantially reduce the flow of gas to said burner to a preselected, relatively low level when said thermal mass reaches said preselected threshold temperature.
Claim 10
Dependent Claim
37 words
A safety device as set forth in claim 1 wherein said burner is provided with a diaphragm operated control valve, the diaphragm being biased by spring means and wherein said sensing means operates to alter the bias.
Claim 11
Dependent Claim
191 words
A safety device for a gas water heater of the type in which combustion products from a gas burner are vented into the room in which the heater is installed, said burner being provided with a diaphragm operated control valve, the diaphragm being biased by spring means through a lever, said safety device comprising: a thermal mass having a preselected thermal capacity, said mass being positioned away from the heating zone of said heater; a probe of preselected thermal conductivity extending from said mass into the heating zone of said heater, thereby to cause the temperature of said mass to increase at an essentially predetermined rate during operation of said burner; the cooling of said mass occurring at an essentially predetermined rate between operations of said burner; selectively operable throttling means for said burner; and a temperature sensing means comprising a temperature sensitive expanding device which is responsive to the temperature of said mass and which is interconnected with said throttling means to lift the biasing lever from the diaphragm as the thermal mass heats for substantially throttling said burner when the temperature of said mass reaches a preselected threshold temperature.
Claim 12
Dependent Claim
191 words
A safety device for a gas water heater of the type in which combustion products from a gas burner are vented into the room in which the heater is installed, said burner being provided with a diaphragm operated control valve, the diaphragm being biased by spring means through a lever, said safety device comprising: a thermal mass having a preselected thermal capacity, said mass being positioned away from the heating zone of said heater; a probe of preselected thermal conductivity extending from said mass into the heating zone of said heater, thereby to cause the temperature of said mass to increase at an essentially predetermined rate during operation of said burner; the cooling of said mass occurring at an essentially predetermined rate between operations of said burner; selectively operable throttling means for said burner; and a temperature sensing means comprising a temperature sensitive expanding device which is responsive to the temperature of said mass and which is interconnected with said throttling means to lift the biasing lever from the diaphragm as the thermal mass heats for substantially throttling said burner when the temperature of said mass reaches a preselected threshold temperature.
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) | 1979-07-27 | 1980-01-26 | 1980-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-27 | 1984-01-26 | 1984-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-27 | 1988-01-26 | 1988-07-27 | $7700.00 | Window Closed / Lapsed |