US3813630A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermostat
Assignee: Individual
•
Filing: 1973-05-21
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Granted: 1974-05-28
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Expires: 1993-05-21
Abstract
Abstract An ON, OFF switch for a load is controlled by a primary bimetallic plate or other temperature sensor, such as an hydraulic bulb. In addition to sensing the temperature of the controlled space, the primary sensor receives heat from a heater in series with the load or from the switch during the ON condition. A mechanical transmission interconnects the primary sensor and the switch. Connected in such transmission so as to be able to vary its effective length, is a secondary bimetallic plate or other temperature sensor. This secondary sensor receives from the switch some of the heat generated therein by passage of the load current. In this way the secondary sensor at least in part compensates for the effect on the switch of the heating of the primary sensor. The advantage of this arrangement is reduction of ''''droop''''. There is a heater for heating the secondary sensor in the OFF condition of the switch. The combined effect of the two heaters and the two sensors is to enable a relatively high cycle rate and small ''''room swing'''' to be obtained at the same time as a relatively small ''''droop''''.
Inventors
- 👤 J Dalzell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:18
CPC Classifications
H; H05; H05B; H05B1/00; H05B1/02; H05B1/0227; H05B1/0252; H01; H01H; H01H37/00; H01H37/02; H01H37/12; H01H37/14
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
181 words
A thermostat for controlling the temperature of a space, comprising a. a switch having an ON and an OFF condition, b. means for connecting said switch in the ON condition in series with a load, c. primary temperature sensor means for sensing the temperature of said space, d. a transmission connected between said primary sensor means and said switch for actuating the latter upon movement of the former. e. means for applying heat proportional to load current through the switch to said primary sensor means during the ON condition of said switch, f. secondary temperature sensor means located adjacent the switch to receive heat generated in the switch by load current during the ON condition, g. said secondary sensor means being connected in said transmission to vary the effective length thereof in accordance with the temperature sensed by said secondary sensor means whereby at least in part to compensate for the effect on the switch of said primary sensor means, h. a heater located for heating said secondary sensor means, i. and means for energising and heater during the OFF condition.
Claim 2
Dependent Claim
181 words
A thermostat for controlling the temperature of a space, comprising a. a switch having an ON and an OFF condition, b. means for connecting said switch in the ON condition in series with a load, c. primary temperature sensor means for sensing the temperature of said space, d. a transmission connected between said primary sensor means and said switch for actuating the latter upon movement of the former. e. means for applying heat proportional to load current through the switch to said primary sensor means during the ON condition of said switch, f. secondary temperature sensor means located adjacent the switch to receive heat generated in the switch by load current during the ON condition, g. said secondary sensor means being connected in said transmission to vary the effective length thereof in accordance with the temperature sensed by said secondary sensor means whereby at least in part to compensate for the effect on the switch of said primary sensor means, h. a heater located for heating said secondary sensor means, i. and means for energising and heater during the OFF condition.
Claim 3
Dependent Claim
39 words
A thermostat according to claim 1, wherein said means for applying heat to said primary sensor means comprises a further heater located adjacent said primary sensor means, and means for connecting said further heater in series with the load.
Claim 4
Dependent Claim
15 words
A thermostat according to claim 2, wherein said primary sensor means comprises a bimetallic plate.
Claim 5
Dependent Claim
33 words
A thermostat according to claim 1, wherein said secondary sensor means comprises a U-shaped bimetallic plate having a pair of legs forming a cavity between them, said heater being located in said cavity.
Claim 6
Dependent Claim
44 words
A thermostat according to claim 4, wherein said transmission comprises a first pin extending from the primary sensor means to one leg of the secondary sensor means and a second pin extending from the other leg of the secondary sensor means to the switch.
Claim 7
Dependent Claim
20 words
A thermostat according to claim 1, wherein said primary sensor means comprises an assembly of an hydraulic bulb and bellows.
Claim 8
Dependent Claim
37 words
A thermostat according to claim 6, wherein said means for applying heat to said primary sensor means comprises a further heater located adjacent said bulb, and means for connecting said further heater in series with the load.
Claim 9
Dependent Claim
46 words
A thermostat according to claim 6, wherein said means for applying heat to said primary sensor means comprises a subsidiary hydraulic bulb connected to said bellows, a further heater located adjacent said subsidiary bulb, and means for connecting said further heater in series with the load.
Claim 10
Dependent Claim
49 words
A thermostat according to claim 6, wherein said means for applying heat to said primary sensor means comprises a subsidiary hydraulic bulb connected to said bellows, said subsidiary bulb being located adjacent the switch to receive heat generated in the switch by the load current during the ON condition.
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) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |