Patent US3581985A successfully refreshed from Google Patents.
US3581985A
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US
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Method and apparatus for minimum droop or rise and differential thermostatic temperature control of heating equipment
Assignee: Westcan Electrical Manufacturing Inc
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Filing: 1966-02-28
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Granted: 1971-06-01
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Expires: 1986-02-28
Abstract
Abstract Thermostats are provided which are useful both for heating and for cooling equipment having a minimum droop characteristic. The described thermostat includes a snap switch in series with the heating or cooling equipment and the load current flowing through the switch to the equipment develops heat in the switch. Droop is minimized by introducing a shield between the switch and the temperature-sensing bimetal, there being an air space both in front of the shield and behind the shield, and the shield having a bright reflecting surface directed toward the switch. Additionally, a heater is provided that is energized during the time intervals when the load is turned off and heating in the switch stops. The overall heating effect resulting from the switch and the heater can be maintained at an approximate norm without regard to the percentage ''''on'''' time of the switch so that a minimum droop or even a rise characteristic can be realized.
Inventors
- 👤 John Bjarni Thorsteinsson
- 👤 Herbert Torrence Hazleton
- 👤 James Welland Dalzell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:16
CPC Classifications
H; H05; H05B; H05B1/00; H05B1/02; H05B1/0202; H05B1/0213
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
175 words
A Thermostat for ambient-temperature-modifying equipment, the thermostat having a minimum droop, comprising: i. a temperature responsive element in an ambient temperature sensing zone; ii. switching means for said equipment, said switching means being separated by an air space from but coupled to and responsive to said temperature-responsive element to energize and deenergize said equipment, said switching means being adapted to carry the operating current of said equipment and inherently developing heat that tends to modify the temperature in said zone; iii. a heat shield interposed in the air space between said switching means and said temperature responsive element, said heat shield subdividing said space into two separate air spaces opposite sides thereof; and iv. a heating element for developing heat that reaches said zone, said thermostat including switching means for energizing said heating element in alternation with said equipment to raise the temperature control point in effect during periods of energization as compared to the temperature control point in effect during sustained nonenergization of the equipment, thereby to reduce droop or actually produce a rise.
Claim 2
Dependent Claim
175 words
A Thermostat for ambient-temperature-modifying equipment, the thermostat having a minimum droop, comprising: i. a temperature responsive element in an ambient temperature sensing zone; ii. switching means for said equipment, said switching means being separated by an air space from but coupled to and responsive to said temperature-responsive element to energize and deenergize said equipment, said switching means being adapted to carry the operating current of said equipment and inherently developing heat that tends to modify the temperature in said zone; iii. a heat shield interposed in the air space between said switching means and said temperature responsive element, said heat shield subdividing said space into two separate air spaces opposite sides thereof; and iv. a heating element for developing heat that reaches said zone, said thermostat including switching means for energizing said heating element in alternation with said equipment to raise the temperature control point in effect during periods of energization as compared to the temperature control point in effect during sustained nonenergization of the equipment, thereby to reduce droop or actually produce a rise.
Claim 3
Dependent Claim
19 words
A thermostat in accordance with claim 1 wherein said heating element is connected in parallel with said switching means.
Claim 4
Dependent Claim
155 words
A thermostat for controlling the operation of atmospheric-temperature-modifying equipment to give a minimum of droop or rise in the atmospheric ambient temperature comprising: i. a pair of supply lines for feeding load current to said equipment; ii. a temperature-sensing element responsive to the ambient temperature in a temperature-sensing zone; iii. switching means in at least one of said lines, said switching means being coupled and responsive to said element, said switching means alternately supplying and interrupting the supply of current to said equipment, said switching means inherently developing heat due to load current therethrough and the heat thus developed tending to produce droop; and iv. a heating element energized under control of said switching means when the latter interrupts load current to the equipment for inversely supplying heat in the thermostat to complement the effect on the temperature-responsive element of the heat developed in the switching means during the periods when the equipment is energized.
Claim 5
Dependent Claim
155 words
A thermostat for controlling the operation of atmospheric-temperature-modifying equipment to give a minimum of droop or rise in the atmospheric ambient temperature comprising: i. a pair of supply lines for feeding load current to said equipment; ii. a temperature-sensing element responsive to the ambient temperature in a temperature-sensing zone; iii. switching means in at least one of said lines, said switching means being coupled and responsive to said element, said switching means alternately supplying and interrupting the supply of current to said equipment, said switching means inherently developing heat due to load current therethrough and the heat thus developed tending to produce droop; and iv. a heating element energized under control of said switching means when the latter interrupts load current to the equipment for inversely supplying heat in the thermostat to complement the effect on the temperature-responsive element of the heat developed in the switching means during the periods when the equipment is energized.
Claim 6
Dependent Claim
44 words
A thermostat in accordance with claim 3, wherein said heating element is a resistor in parallel with the switching means so as to be shunted by the switching means when the latter is closed and being in operation when the switching means is open.
Claim 7
Dependent Claim
29 words
A thermostat in accordance with claim 3, wherein said switching means comprises a snap switch and wherein said temperature-sensing element comprises a bimetal mechanically coupled to said snap switch.
Claim 8
Dependent Claim
154 words
A thermostat for ambient-temperature-modifying equipment, the thermostat having a minimum droop, comprising: i. a temperature-responsive element in an ambient-temperature-sensing zone; ii. switching means for said equipment, said switching means being separated by an air space from but coupled to and responsive to said temperature-responsive element to energize and deenergize said equipment, said switching means being adapted to carry the operating current of said equipment and inherently developing heat that tends to modify the temperature in said zone; iii. a heat shield interposed in the air space between said switching means and said temperature-responsive element, said heat shield subdividing said space into two separate air spaces at opposite sides thereof, iv. a resistance element in said ambient-temperature-sensing zone, and v. said thermostat including means for selectively energizing said resistance element concurrently with said equipment to reduce the temperature difference in said zone between the prevailing ambient temperature in the zone and a selected ambient temperature.
Claim 9
Dependent Claim
154 words
A thermostat for ambient-temperature-modifying equipment, the thermostat having a minimum droop, comprising: i. a temperature-responsive element in an ambient-temperature-sensing zone; ii. switching means for said equipment, said switching means being separated by an air space from but coupled to and responsive to said temperature-responsive element to energize and deenergize said equipment, said switching means being adapted to carry the operating current of said equipment and inherently developing heat that tends to modify the temperature in said zone; iii. a heat shield interposed in the air space between said switching means and said temperature-responsive element, said heat shield subdividing said space into two separate air spaces at opposite sides thereof, iv. a resistance element in said ambient-temperature-sensing zone, and v. said thermostat including means for selectively energizing said resistance element concurrently with said equipment to reduce the temperature difference in said zone between the prevailing ambient temperature in the zone and a selected ambient temperature.
Claim 10
Dependent Claim
154 words
A thermostat for ambient-temperature-modifying equipment, the thermostat having a minimum droop, comprising: i. a temperature-responsive bimetal in an ambient-temperature-sensing zone; ii. a snap-acting switch for said equipment, said switch being separated by an air space from but coupled to and responsive to said temperature-responsive bimetal to energize and deenergize said equipment, said snap-acting switch being adapted to carry the operating current of said equipment and inherently developing heat that tends to modify the temperature in said ambient-temperature-sensing zone; iii. a heat shield interposed in the air space between said switch and said temperature-responsive bimetal, said heat shield subdividing said space into two separate air spaces at opposite sides thereof, and iv. a resistance element in said ambient-temperature-sensing zone, v. said thermostat including means for selectively energizing said resistance element concurrently with said equipment to reduce the temperature difference in said zone between the prevailing ambient temperature in the zone and a selected ambient temperature.
Claim 11
Dependent Claim
154 words
A thermostat for ambient-temperature-modifying equipment, the thermostat having a minimum droop, comprising: i. a temperature-responsive bimetal in an ambient-temperature-sensing zone; ii. a snap-acting switch for said equipment, said switch being separated by an air space from but coupled to and responsive to said temperature-responsive bimetal to energize and deenergize said equipment, said snap-acting switch being adapted to carry the operating current of said equipment and inherently developing heat that tends to modify the temperature in said ambient-temperature-sensing zone; iii. a heat shield interposed in the air space between said switch and said temperature-responsive bimetal, said heat shield subdividing said space into two separate air spaces at opposite sides thereof, and iv. a resistance element in said ambient-temperature-sensing zone, v. said thermostat including means for selectively energizing said resistance element concurrently with said equipment to reduce the temperature difference in said zone between the prevailing ambient temperature in the zone and a selected ambient temperature.
Claim 12
Dependent Claim
124 words
A thermostat for ambient-temperature-modifying equipment, the thermostat having a minimum droop, comprising: i. a temperature-responsive element in an ambient-temperature-sensing zone; ii. switching means for said equipment, said switching means being separated by an air space from but coupled to and responsive to said temperature-responsive element to energize and deenergize said equipment, said switching means being adapted to carry the operating current of said equipment and inherently developing heat that tends to modify the temperature in said zone; iii. and a heat shield interposed in the air space between said switching means and said temperature responsive element, said heat shield subdividing said space into two separate air spaces at opposite sides thereof, said heat shield having a bright reflecting surface directed toward the switching means.
Claim 13
Dependent Claim
124 words
A thermostat for ambient-temperature-modifying equipment, the thermostat having a minimum droop, comprising: i. a temperature-responsive element in an ambient-temperature-sensing zone; ii. switching means for said equipment, said switching means being separated by an air space from but coupled to and responsive to said temperature-responsive element to energize and deenergize said equipment, said switching means being adapted to carry the operating current of said equipment and inherently developing heat that tends to modify the temperature in said zone; iii. and a heat shield interposed in the air space between said switching means and said temperature responsive element, said heat shield subdividing said space into two separate air spaces at opposite sides thereof, said heat shield having a bright reflecting surface directed toward the switching means.
Claim 14
Independent Claim
155 words
A method of thermostatically controlling the operation of atmospheric-temperature-modifying equipment to give a minimum of droop or a rise in the atmospheric ambient temperature comprising the steps of: i. establishing an ambient-temperature-sensing zone: ii. producing a signal function which is responsive to a difference between the temperature of said zone and a selected ambient temperature; iii. utilizing said signal to energize said equipment when said temperature difference is excessive, said equipment modifying the ambient atmospheric temperature in the appropriate direction to reduce said difference: iv. producing a first heating effect that raises the ambient temperature in said zone incidental to step iii. during energized periods of the equipment and as a result of the load current of such equipment; and v. producing a supplemental heating effect during the full periods of time between said energized periods to raise the ambient temperature in said zone for at least compensating for interruptions of said first heAting effect.
Claim 15
Independent Claim
155 words
A method of thermostatically controlling the operation of atmospheric-temperature-modifying equipment to give a minimum of droop or a rise in the atmospheric ambient temperature comprising the steps of: i. establishing an ambient-temperature-sensing zone: ii. producing a signal function which is responsive to a difference between the temperature of said zone and a selected ambient temperature; iii. utilizing said signal to energize said equipment when said temperature difference is excessive, said equipment modifying the ambient atmospheric temperature in the appropriate direction to reduce said difference: iv. producing a first heating effect that raises the ambient temperature in said zone incidental to step iii. during energized periods of the equipment and as a result of the load current of such equipment; and v. producing a supplemental heating effect during the full periods of time between said energized periods to raise the ambient temperature in said zone for at least compensating for interruptions of said first heAting effect.
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) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |