US3870985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermostatic switch with solid state heater
Assignee: Fasco Controls Corp
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Filing: 1973-10-01
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Granted: 1975-03-11
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Expires: 1993-10-01
Abstract
Abstract The switch has a base, a cover, and three, spaced terminals that are secured intermediate their ends in the base to extend at opposite ends beneath the base, and into the cover, respectively. An electrical heater element is secured at opposite ends to two of the terminals to extend therebetween within the cover. A bimetallic, temperature-responsive switch arm is secured at one end to a tab which projects laterally from one of said two terminals, and normally is releasably engaged at its opposite end with the third terminal. The switch arm can be calibrated after assembly electrically by adjusting the power supplied to the heater element, or mechanically by inserting an instrument through a hole in the base to bend said tab to increase or decrease the tension in said arm when closed.
Inventors
- 👤 Charles John Hire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:46
CPC Classifications
H; H01; H01H; H01H37/00; H01H37/02; H01H37/12; H01H37/20; H01H37/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
198 words
A thermostatic switch, comprising a housing having therein a chamber and a hole connecting the chamber to the exterior of the housing, three spaced electrically conductive terminals secured to said housing, each having its opposite Ends, respectively, projecting into said housing and extending exteriorly of said housing, an electrically operable heater element mounted in said chamber and connected at opposite ends to two of said terminals, a metal tab secured to and projecting from one of said two terminals and registering with said hole, a flexible, bi-metallic switch arm mounted in said housing adjacent said heater element and having a free end overlying the third of said three terminals, an electrical contact secured on said free end of said arm, and means securing the opposite end of said arm to said tab for pivotal movement, upon predetermined changes in its ambient temperature, between a position in which the contact on the free end of said arm is in engagement with said third terminal and a position in which said contact is disengaged from said third terminal, said tab being bendable manually by an instrument insertable through said hole in said housing to vary the tension in said arm.
Claim 2
Dependent Claim
198 words
A thermostatic switch, comprising a housing having therein a chamber and a hole connecting the chamber to the exterior of the housing, three spaced electrically conductive terminals secured to said housing, each having its opposite Ends, respectively, projecting into said housing and extending exteriorly of said housing, an electrically operable heater element mounted in said chamber and connected at opposite ends to two of said terminals, a metal tab secured to and projecting from one of said two terminals and registering with said hole, a flexible, bi-metallic switch arm mounted in said housing adjacent said heater element and having a free end overlying the third of said three terminals, an electrical contact secured on said free end of said arm, and means securing the opposite end of said arm to said tab for pivotal movement, upon predetermined changes in its ambient temperature, between a position in which the contact on the free end of said arm is in engagement with said third terminal and a position in which said contact is disengaged from said third terminal, said tab being bendable manually by an instrument insertable through said hole in said housing to vary the tension in said arm.
Claim 3
Dependent Claim
198 words
A thermostatic switch, comprising a housing having therein a chamber and a hole connecting the chamber to the exterior of the housing, three spaced electrically conductive terminals secured to said housing, each having its opposite Ends, respectively, projecting into said housing and extending exteriorly of said housing, an electrically operable heater element mounted in said chamber and connected at opposite ends to two of said terminals, a metal tab secured to and projecting from one of said two terminals and registering with said hole, a flexible, bi-metallic switch arm mounted in said housing adjacent said heater element and having a free end overlying the third of said three terminals, an electrical contact secured on said free end of said arm, and means securing the opposite end of said arm to said tab for pivotal movement, upon predetermined changes in its ambient temperature, between a position in which the contact on the free end of said arm is in engagement with said third terminal and a position in which said contact is disengaged from said third terminal, said tab being bendable manually by an instrument insertable through said hole in said housing to vary the tension in said arm.
Claim 4
Dependent Claim
198 words
A thermostatic switch, comprising a housing having therein a chamber and a hole connecting the chamber to the exterior of the housing, three spaced electrically conductive terminals secured to said housing, each having its opposite Ends, respectively, projecting into said housing and extending exteriorly of said housing, an electrically operable heater element mounted in said chamber and connected at opposite ends to two of said terminals, a metal tab secured to and projecting from one of said two terminals and registering with said hole, a flexible, bi-metallic switch arm mounted in said housing adjacent said heater element and having a free end overlying the third of said three terminals, an electrical contact secured on said free end of said arm, and means securing the opposite end of said arm to said tab for pivotal movement, upon predetermined changes in its ambient temperature, between a position in which the contact on the free end of said arm is in engagement with said third terminal and a position in which said contact is disengaged from said third terminal, said tab being bendable manually by an instrument insertable through said hole in said housing to vary the tension in said arm.
Claim 5
Dependent Claim
88 words
A thermostatic switch as defined in claim 1, wherein said two terminals project at their inner ends into said chamber in spaced, parallel relation, said heater element extends transversely between said inner ends of said two terminals adjacent one side of said chamber, said remaining terminal has its inner end located adjacent the opposite side of said chamber in spaced relation to said heater element, and said free end of said arm is pivotal in the space between said element and said inner end of said remaining terminal.
Claim 6
Dependent Claim
35 words
A thermostatic switch as defined in claim 2, including a magnet mounted on said free end of said switch arm and operative to resist movement of said contact from its closed to its open position.
Claim 7
Dependent Claim
52 words
A thermostatic switch as defined in claim 2, wherein said tab is struck from said one terminal to project into said chamber between said heater element and said opening, and said one end of said arm is fastened to said tab adjacent the end thereof that is integral with said one terminal.
Claim 8
Dependent Claim
59 words
A thermostatic switch as defined in claim 2, wherein said tab projects from said one terminal at a point offset from said heater element, said switch arm is generally U-shaped in configuration and has one leg thereof secured to said tab and the opposite leg thereof extending between said heater element and said inner end of said third terminal.
Claim 9
Dependent Claim
47 words
In combination with a thermostatic switch as defined in claim 11, a power supply and a variable resistance connected in series with said heater element through a pair of said terminals, whereby said switch may be calibrated selectively by varying said resistance and by bending said tab.
Claim 10
Dependent Claim
173 words
A thermostat switch, comprising a housing having therein a chamber, three spaced electrically-conductive terminals secured to said housing, and each having its opposite ends projecting, respectively, into said chamber and exteriorly of said housing, an electrically operable heater element secured at opposite ends thereof in said chamber to the inner ends of two of said terminals and extending transversely therebetween in spaced relation to the inner end of the third terminal, a flexible, bi-metallic switch arm secured at one end to one of said two terminals and having its opposite, free end extending into the space between said heater element and said inner end of said third terminal, an electrical contact secured to said free end of said switch arm and registering with said inner end of said third terminal for selective engagement therewith upon predetermined changes in the ambient temperature about said arm, and means for adjusting the resilient force statically exerted on said free end of said arm when said contact is engaged with said inner end of said third terminal.
Claim 11
Dependent Claim
173 words
A thermostat switch, comprising a housing having therein a chamber, three spaced electrically-conductive terminals secured to said housing, and each having its opposite ends projecting, respectively, into said chamber and exteriorly of said housing, an electrically operable heater element secured at opposite ends thereof in said chamber to the inner ends of two of said terminals and extending transversely therebetween in spaced relation to the inner end of the third terminal, a flexible, bi-metallic switch arm secured at one end to one of said two terminals and having its opposite, free end extending into the space between said heater element and said inner end of said third terminal, an electrical contact secured to said free end of said switch arm and registering with said inner end of said third terminal for selective engagement therewith upon predetermined changes in the ambient temperature about said arm, and means for adjusting the resilient force statically exerted on said free end of said arm when said contact is engaged with said inner end of said third terminal.
Claim 12
Dependent Claim
41 words
In combination with a thermostatic switch as defined in claim 7, means for applying an adjustable voltage drop across opposite ends of said heater element adjustably to elevate the ambient Temperature about said arm by the heat emitted by said element.
Claim 13
Dependent Claim
38 words
A thermostatic switch as defined in claim 7, wherein said adjusting means comprises means in said housing operable manually from the exterior of said housing to bend said free end of said arm relative to said one terminal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |