US3659155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current sensing apparatus
Assignee: Robertshaw Controls Co
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Filing: 1969-03-03
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Granted: 1972-04-25
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Expires: 1989-03-03
Abstract
Abstract This application relates to a fan control apparatus for actuating a fan to circulate air over a plurality of electric environmental change elements included in a temperature control system. The apparatus includes a fan in circuit with switch means which is operative in response to an electrical signal to actuate the fan. A sensing element is disposed in electrically inductive relationship with the environmental change elements and is responsive to energization of any one of such elements to generate said electrical signal and effect closing of the switch means to actuate the fan. The signal will continue and maintain the fan operative as long as the environmental change elements are energized and will be rendered inoperative when the last change element is de-energized thus discontinuing said signal and deactuating said fan.
Inventors
- 👤 William W Chambers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:41
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/275; G05D23/1906; G05D23/1912
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
156 words
Current sensing control apparatus for operation of an electrical load circuit and comprising: gate controlled switch means for controlling current in said load circuit; a plurality of switches; electrical leads connected with said switches and leading to separate electrical elements; time delay means for actuating said switches at different times; current sensing means inductively coupled to said electrical leads and responsive to current flow in any one of said electrical leads to produce an electrical signal; and amplification means electrically coupled to said sensing means and to the gate of said switch means and operable to receive said electrical signal and amplify it to produce said triggering signal whereby current flowing in any one of said electrical leads will be sensed by said sensing means to produce said electrical signal and said amplification means will amplify said signal to impose said triggering signal on said gate to trigger said switch means and operate said load circuit.
Claim 2
Dependent Claim
156 words
Current sensing control apparatus for operation of an electrical load circuit and comprising: gate controlled switch means for controlling current in said load circuit; a plurality of switches; electrical leads connected with said switches and leading to separate electrical elements; time delay means for actuating said switches at different times; current sensing means inductively coupled to said electrical leads and responsive to current flow in any one of said electrical leads to produce an electrical signal; and amplification means electrically coupled to said sensing means and to the gate of said switch means and operable to receive said electrical signal and amplify it to produce said triggering signal whereby current flowing in any one of said electrical leads will be sensed by said sensing means to produce said electrical signal and said amplification means will amplify said signal to impose said triggering signal on said gate to trigger said switch means and operate said load circuit.
Claim 3
Dependent Claim
29 words
Current sensing control apparatus as set forth in claim 1 wherein: said sensing means includes a ferromagnetic core; and said amplification means includes coil means wound on said core.
Claim 4
Dependent Claim
36 words
Current sensing control apparatus as set forth in claim 1 that includes: capaticance means connected with the gate of said switch means to absorb current surges introduced thereto to prevent accidental actuation of said switching means.
Claim 5
Dependent Claim
22 words
Current sensing control apparatus as set forth in claim 1 wherein: said electrical elements are in the form of resistance heating elements.
Claim 6
Dependent Claim
75 words
Current sensing control apparatus as set forth in claim 1 wherein: said electrical elements are in the form of temperature change element; and said load circuit includes fan means responsive to operation of said load circuit to circulate fluid in heat exchange relationship with said temperature change elements whereby said fan means will be operated whenever any of said temperature change elements is energized to thereby prevent said temperature change elements from reaching excessive temperature.
Claim 7
Dependent Claim
64 words
Current sensing control apparatus as set forth in claim 1 wherein: said electrical elements are in the form of heating elements; and said load circuit includes fan means responsive to operation of said load circuit for circulating fluid in heat exchange relationship with said heating elements whereby said fan means will be actuated whenever current is conducted in any one of said electrical leads.
Claim 8
Dependent Claim
59 words
Current sensing control apparatus as set forth in claim 5 that includes: thermostat means for sensing the temperature of the fluid circulated in heat exchange relationship with said temperature change elements and connected with said temperature change elements, said thermostat being responsive to the temperature of said fluid falling outside a predetermined range to actuate said temperature change elements.
References Cited (Backward Citations)
US3329869A
Cited
US3419756A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |