US3869619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contactless electrical thermostat employing a bimetallic strip
Assignee: Illinois Tool Works Inc
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Filing: 1973-11-16
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Granted: 1975-03-04
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Expires: 1993-11-16
Abstract
Abstract A thermostat employing a bimetallic strip carrying a permanent magnet and a saturable magnetic core positioned at an adjacent fixed location is disclosed. The magnetic core has a primary winding that is supplied with electrical pulses and a secondary winding which is coupled to an output circuit, preferably including a Schmitt trigger circuit. When the bimetallic strip is bent due to the environmental temperature so that the permanent magnet is closely magnetically coupled to the magnetic core, the core approaches saturation and the pulse output signal decreases in magnitude. The output circuit is constructed to have electrical hysteresis so that the ''''turn on'''' and ''''turn off'''' levels of the circuit are different.
Inventors
- 👤 Charles Carl Camillo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:13
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1919; G05D23/275
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
142 words
An electrical thermostat comprising a saturable magnetic element, a bimetallic strip movable with respect to said magnetic element in response to environmental temperature, a permanent magnet affixed to said bimetallic strip which is movable to a first position in close magnetic coupling with said magnetic element so that said magnetic element will be relatively magnetically saturated when the environmental temperature is at a first value and is movable to a second position wherein said magnetic element will be relatively magnetically unsaturated and the environmental temperature is at a second value, a primary winding and a secondary winding associated with said magnetic element, means for supplying electrical time-varying signals to said primary winding and output means coupled to said secondary winding for receiving time-varying output voltage signals the magnitude of which varies inversely with the degree of magnetic saturation of said magnetic element.
Claim 2
Dependent Claim
142 words
An electrical thermostat comprising a saturable magnetic element, a bimetallic strip movable with respect to said magnetic element in response to environmental temperature, a permanent magnet affixed to said bimetallic strip which is movable to a first position in close magnetic coupling with said magnetic element so that said magnetic element will be relatively magnetically saturated when the environmental temperature is at a first value and is movable to a second position wherein said magnetic element will be relatively magnetically unsaturated and the environmental temperature is at a second value, a primary winding and a secondary winding associated with said magnetic element, means for supplying electrical time-varying signals to said primary winding and output means coupled to said secondary winding for receiving time-varying output voltage signals the magnitude of which varies inversely with the degree of magnetic saturation of said magnetic element.
Claim 3
Dependent Claim
20 words
A thermostat as claimed in claim 1 wherein said saturable magnEtic element is a magnetic core of a torroidal shape.
Claim 4
Dependent Claim
16 words
A thermostat as claimed in claim 1 wherein said time-varying output voltage signals are pulse signals.
Claim 5
Dependent Claim
36 words
A thermostat as claimed in claim 1 comprising mechanical calibration means for adjusting the orientation of said bimetallic strip and electrical adjustment means coupled to said output means for adjusting the temperature response of said thermostat.
Claim 6
Dependent Claim
16 words
A thermostat as claimed in claim 4 wherein said time-varying output voltage signals are pulse signals.
Claim 7
Dependent Claim
20 words
A thermostat as claimed in claim 5 wherein said saturable magnetic element is a magnetic core of a torroidal shape.
Claim 8
Dependent Claim
144 words
An electrical thermostat comprising a saturable magnetic element, a bimetallic strip movable with respect to said magnetic element in response to environmental temperature, a permanent magnet affixed to said bimetallic strip which is movable to a first position in close magnetic coupling with said magnetic element so that said magnetic element will be relatively magnetically saturated when the environmental temperature is at a first value and is movable to a second position wherein said magnetic element will be relatively magnetically unsaturated and the environmental temperature is at a second value, a primary winding and a secondary winding associated with said magnetic element, means for supplying electrical time-varying signals to said primary winding and a Schmitt trigger circuit coupled to said secondary winding for receiving time-varying output voltage signals the magnitude of which varies inversely with the degree of magnetic saturation of said magnetic element.
Claim 9
Dependent Claim
144 words
An electrical thermostat comprising a saturable magnetic element, a bimetallic strip movable with respect to said magnetic element in response to environmental temperature, a permanent magnet affixed to said bimetallic strip which is movable to a first position in close magnetic coupling with said magnetic element so that said magnetic element will be relatively magnetically saturated when the environmental temperature is at a first value and is movable to a second position wherein said magnetic element will be relatively magnetically unsaturated and the environmental temperature is at a second value, a primary winding and a secondary winding associated with said magnetic element, means for supplying electrical time-varying signals to said primary winding and a Schmitt trigger circuit coupled to said secondary winding for receiving time-varying output voltage signals the magnitude of which varies inversely with the degree of magnetic saturation of said magnetic element.
Claim 10
Dependent Claim
20 words
A thermostat as claimed in claim 7 wherein said saturable magnetic element is a magnetic core of a torroidal shape.
Claim 11
Dependent Claim
16 words
A thermostat as claimed in claim 7 wherein said time-varying output voltage signals are pulse signals.
Claim 12
Dependent Claim
37 words
A thermostat as claimed in claim 7 comprising mechanical calibration means for adjusting the orientation of said bemetallic strip and electrical adjustment means coupled to said Schmitt trigger circuit for adjusting the temperature response of said thermostat.
Claim 13
Dependent Claim
16 words
A thermostat as claimed in claim 10 wherein said time-varying output voltage signals are pulse signals.
Claim 14
Dependent Claim
20 words
A thermostat as claimed in claim 11 wherein said saturable magnetic element is a magnetic core of a torroidal shape.
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) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |