Patent US3665152A successfully refreshed from Google Patents.
US3665152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Iron with overtemperature protection means
Assignee: General Electric Co
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Filing: 1971-05-20
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Granted: 1972-05-23
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Expires: 1991-05-20
Abstract
Abstract A flatiron having an overtemperature protection means operating in conjunction with a thermostat to prevent an excessive soleplate temperature in the event of failure of the thermostat.
Inventors
- 👤 Harold S Foster
- 👤 Wendell C Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:10
CPC Classifications
D; D06; D06F; D06F75/00; D06F75/08; D06F75/26
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
293 words
In an electric flatiron with a soleplate and an associated electric heater circuit of sufficient wattage to achieve abnormally high soleplate temperatures upon continuous heater operation, a thermostat limiting soleplate temperature to a normal maximum selected operating temperature by switching of the electric power supply to the electric heater, that improvement comprising, an overtemperature protection assembly to disconnect said electric heater from electric power before abnormally high soleplate tempeRatures occur in the event of any failure of the thermostat to switch off the power, said assembly comprising: first and second circuit members in electrical conducting relationship and in said electric heater circuit while being electrically isolated from said soleplate; an alloy sensor having essentially eutectic composition and a melting point at least as high as said normal maximum temperature and less than any abnormally high temperature, with said alloy physically maintaining said first and second circuit members in electrical conducting relationship without being an essential electric circuit element; means providing a bias to separate said circuit members when said alloy melts; means to heat said circuit members and said alloy sensor by limited heat transfer from said soleplate resulting in an alloy temperature below soleplate temperature during normal operation at the maximum normal operating temperature; and electric resistance means including at least one of said circuit members through which heater current flows to supply an additional increment of heat to said alloy sensor, said increment being insufficient to increase the temperature of said alloy sensor to its melting point at normal maximum operating temperature over an extended time under thermostat control, and sufficient to increase alloy sensor temperature to its selected melting point and open the heater circuit if said thermostat does not open the circuit before an abnormally high soleplate temperature occurs.
Claim 2
Dependent Claim
293 words
In an electric flatiron with a soleplate and an associated electric heater circuit of sufficient wattage to achieve abnormally high soleplate temperatures upon continuous heater operation, a thermostat limiting soleplate temperature to a normal maximum selected operating temperature by switching of the electric power supply to the electric heater, that improvement comprising, an overtemperature protection assembly to disconnect said electric heater from electric power before abnormally high soleplate tempeRatures occur in the event of any failure of the thermostat to switch off the power, said assembly comprising: first and second circuit members in electrical conducting relationship and in said electric heater circuit while being electrically isolated from said soleplate; an alloy sensor having essentially eutectic composition and a melting point at least as high as said normal maximum temperature and less than any abnormally high temperature, with said alloy physically maintaining said first and second circuit members in electrical conducting relationship without being an essential electric circuit element; means providing a bias to separate said circuit members when said alloy melts; means to heat said circuit members and said alloy sensor by limited heat transfer from said soleplate resulting in an alloy temperature below soleplate temperature during normal operation at the maximum normal operating temperature; and electric resistance means including at least one of said circuit members through which heater current flows to supply an additional increment of heat to said alloy sensor, said increment being insufficient to increase the temperature of said alloy sensor to its melting point at normal maximum operating temperature over an extended time under thermostat control, and sufficient to increase alloy sensor temperature to its selected melting point and open the heater circuit if said thermostat does not open the circuit before an abnormally high soleplate temperature occurs.
Claim 3
Dependent Claim
15 words
Apparatus as described in claim 1 wherein said normal maximum temperature is around 550* F.
Claim 4
Dependent Claim
28 words
Apparatus as described in claim 2 having resilient means in said circuit members to separate said members and break said circuit prior to a 950* F. soleplate temperature.
Claim 5
Dependent Claim
43 words
Apparatus as described in claim 2 wherein said circuit members are connected in series with one another and at least one of said circuit members has an electrical resistance to substantially generate the increment of heat by the current flow to said heater.
Claim 6
Dependent Claim
18 words
Apparatus as described in claim 4 wherein one of said circuit members is formed of a spring member.
Claim 7
Dependent Claim
16 words
Apparatus as described in claim 4 wherein said heat generating circuit member is said spring member.
Claim 8
Dependent Claim
19 words
Apparatus as described in claim 4 wherein the other circuit member is a wire connected to said heating element.
Claim 9
Dependent Claim
15 words
Apparatus as described in claim 5 wherein said spring member is connected to said thermostat.
Claim 10
Dependent Claim
25 words
Apparatus as described in claim 5 wherein said resistance spring member and wire are partially overlapping and are loop-connected at the overlap by said alloy.
Claim 11
Dependent Claim
28 words
Apparatus as described in claim 9 wherein said spring member is flat and is under tension and biased to separate sharply from said wire when said alloy melts.
Claim 12
Dependent Claim
22 words
Apparatus as described in claim 10 wherein said wire is also formed in a loop between said spring and said heating member.
Claim 13
Dependent Claim
218 words
In an electric flatiron with a soleplate and an associated electric heater circuit with a heater member in the soleplate and thermostat means for normally controlling the soleplate to a normal maximum selected operating temperature, an overtemperature protection assembly comprising; two circuit members in the electric circuit in electrical conducting relationship with each other, eutectic sensor means bonding said members together to ensure said electrical relationship, said eutectic being a material not meltable in its operating environment with a soleplate temperature at or below its normal maximum operating temperature and meltable in its operating environment prior to soleplate melting temperature, said circuit members being electrically isolated from said soleplate and positioned in the iron to receive heat in said environment by conduction, convection, and radiation, at least one of said members being self-heating to provide supplemental I2R heat to increase the temperature of said sensor so that a curve of sensor versus soleplate temperature under no self-heat conditions is raised by a range of 125* -250* F. during a condition of continuous heat up and by a range of 75* - 90* F. in a soak condition of the iron whereby the sensor temperature more closely follows the soleplate temperature and protects the iron from overtemperature conditions, and means to separate said members upon melting of the eutectic.
Claim 14
Dependent Claim
218 words
In an electric flatiron with a soleplate and an associated electric heater circuit with a heater member in the soleplate and thermostat means for normally controlling the soleplate to a normal maximum selected operating temperature, an overtemperature protection assembly comprising; two circuit members in the electric circuit in electrical conducting relationship with each other, eutectic sensor means bonding said members together to ensure said electrical relationship, said eutectic being a material not meltable in its operating environment with a soleplate temperature at or below its normal maximum operating temperature and meltable in its operating environment prior to soleplate melting temperature, said circuit members being electrically isolated from said soleplate and positioned in the iron to receive heat in said environment by conduction, convection, and radiation, at least one of said members being self-heating to provide supplemental I2R heat to increase the temperature of said sensor so that a curve of sensor versus soleplate temperature under no self-heat conditions is raised by a range of 125* -250* F. during a condition of continuous heat up and by a range of 75* - 90* F. in a soak condition of the iron whereby the sensor temperature more closely follows the soleplate temperature and protects the iron from overtemperature conditions, and means to separate said members upon melting of the eutectic.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |