Patent US3819904A successfully refreshed from Google Patents.
US3819904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control circuit for timed food heating device
Assignee: Hoover Co
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Filing: 1973-03-16
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Granted: 1974-06-25
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Expires: 1993-03-16
Abstract
Abstract Control circuit for a timed food heating device such as an electric toaster having a heat-up, cool-down timer. The invention provides for selectively operating the device in a (1) normal, high-heat output mode for an operational cycle, in a (2) lower heat output mode for a somewhat longer operational cycle, or in a (3) low heat output mode during the initial portion of the operational cycle and a high heat output mode during the latter portion of such operational cycle.
Inventors
- 👤 E Novak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:04
CPC Classifications
A; A47; A47J; A47J37/00; A47J37/06; A47J37/08; A47J37/0814
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
134 words
In a timed food heating device having a main heater connectable to a source of electrical energy and a timer for controlling energization of said main heater through an operational cycle, said timer including a heat-responsive member as well as a timer heater and the latter being adapted to heat said member when energized from said source, the improvement comprising first means for selective connection in and disconnection from circuit with said main heater to vary the heat output thereof, second means for selective connection in and disconnection from circuit with said timer heater to vary heat output to said heat-responsive timer member, and switch means selectively connecting and disconnecting said first means from circuit with said main heater and also selectively connecting and disconnecting said second means from circuit with said timer heater.
Claim 2
Dependent Claim
134 words
In a timed food heating device having a main heater connectable to a source of electrical energy and a timer for controlling energization of said main heater through an operational cycle, said timer including a heat-responsive member as well as a timer heater and the latter being adapted to heat said member when energized from said source, the improvement comprising first means for selective connection in and disconnection from circuit with said main heater to vary the heat output thereof, second means for selective connection in and disconnection from circuit with said timer heater to vary heat output to said heat-responsive timer member, and switch means selectively connecting and disconnecting said first means from circuit with said main heater and also selectively connecting and disconnecting said second means from circuit with said timer heater.
Claim 3
Dependent Claim
161 words
The construction of claim 1 wherein an operational cycle of said timer includes an initial heat-up phase during which said timer heater is energized to heat said heat-reponsive member and a subsequent cool-down phase during which said timer heater is de-energized to permit cooling of said heat-responsive member, wherein said switch means has one position in which said first means is connected in circuit with said main heater during both the heat-up and cool-down phases of operation of said timer, wherein said switch means has another position in which said first means is disconnected from circuit with said main heater during both the heat-up and cool-down phases of operation of said timer, and wherein said switch means has still another position in which said first means is connected in circuit with said main heater during the heat-up phase of operation of said timer and is disconnected from circuit with said main heater during the cool-down phase of operation of said timer.
Claim 4
Dependent Claim
54 words
The construction of claim 2 wherein said first means comprises a first resistance selectively connectable in series with said main heater to reduce the heat output of the latter, and wherein said second means comprises a second resistance selectively connectable in shunt with said timer heater to reduce the heat output of the latter.
Claim 5
Dependent Claim
92 words
The construction of claim 1 wherein said first and second means function reduce the heat output of said main and timer heaters respectively when in circuit therewith, wherein said switch means has one position in which said first means is connected in circuit with said main heater and said second means is disconnected from circuit with said timer heater, and wherein said switch means has another position in which said first means is disconnected from circuit with said main heater and said second means is connected in circuit with said timer heater.
Claim 6
Dependent Claim
38 words
The construction of claim 4 wherein said first means comprises a first resistance selectively connectable in series with said main heater, and wherein said second means comprises a second resistance selectively connectable in shunt with said timer heater.
Claim 7
Dependent Claim
26 words
The construction of claim 5 wherein said switch means is in shunt relation with said first resistance and is in series relation with said second resistance.
Claim 8
Dependent Claim
218 words
The construction of claim 1 wherein an operational cycle of said timer includes an initial heat-up phase during which said timer heater is energized to heat said heat-reponsive member and a subsequent cool-down phase during which said timer heater is de-energized to permit cooling of said heat-responsive member, wherein said switch means has one position in which said first means is connected in circuit with said main heater during both the heat-up and cool-down phases of operation of said timer while said second means is disconnected from circuit with said timer heater during both aforesaid phases of operation of said timer, wherein said switch means has another position in which said first means is disconnected from circuit with said main heater during both the heat-up and cool-down phases of operation of said timer while said second means is connected in circuit with said timer heater during both aforesaid phases of operation of said timer, and wherein said swich means has still another position in which said second means is disconnected from circuit with said timer heater while said first means is connectEd in circuit with said main heater during the heat-up phase of operation of said timer and said first means is disconnected from circuit with said main heater during the cool-down phase of operation of said timer.
Claim 9
Dependent Claim
71 words
The construction of claim 7 wherein said first means is selectively connectable in series with said main heater, wherein said second means is selectively connectable in shunt with said timer heater, and wherein said switch means is in shunt relation with said first means and in series relation with said second means to effect connection and disconnection aforesaid of said first and second means with said main and timer heaters respectively.
Claim 10
Dependent Claim
13 words
The construction of claim 8 wherein said first and second means are resistances.
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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |