US3728581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ground fault circuit interrupter
Assignee: Individual
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Filing: 1971-05-27
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Granted: 1973-04-17
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Expires: 1991-05-27
Abstract
Abstract A ground fault circuit interrupter and/or indicator comprising a relay switch and/or indicator lamp connected on one side to the grounded frame of an appliance or other part, and on the other side to the neutral wire or to the grounding wire of the electrical service. Current leaking from the hot line to the appliance frame due to moisture or faulty insulation passes through the relay coil and/or indicator to the neutral line or grounding wire of the service, and this actuates the relay switch to open the hot line circuit to the appliance. In one embodiment, there is an additional circuit breaker in the hot line comprising a relay switch serially connected to the hot line, which is energized by excessive current flow, as in a line-to-line short.
Inventors
- 👤 D Adamo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:42
CPC Classifications
H; H01; H01R; H01R13/00; H01R13/66; H01R13/70; H01R13/713; H01R13/7135; H02; H02H; H02H3/00; H02H3/08; H02H3/10; H02H3/105; H02H3/16; H02H3/162
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
186 words
A device for use with an electrical appliance having a grounded frame and including an electrical connection having a hot wire, neutral wire, and a grounding wire connected to said frame, said electrical connection being connected to an electrical service consisting of a hot conductor, a neutral conductor, and a grounding conductor, said device comprising: a hot line connecting said hot conductor of said electrical service to said hot wire of said appliance electrical connection; a neutral line connecting said neutral conductor of said electrical service to said neutral wire of said appliance electrical connection; a grounding line connected to said grounding wire of said appliance electrical connection and to said grounding conductor of said electrical service; current-flow-interrupting means serially connected to said grounding line for opening the hot line responsive to the flow of leakage current along the grounding line due to the existence of a ground fault in said appliance; said current-flow-interrupting means comprising a normallyclosed relay switch in said hot line, said relay switch being opened by an electromagnet serially connected between said grounding line and said grounding conductor of said electrical service.
Claim 2
Independent Claim
186 words
A device for use with an electrical appliance having a grounded frame and including an electrical connection having a hot wire, neutral wire, and a grounding wire connected to said frame, said electrical connection being connected to an electrical service consisting of a hot conductor, a neutral conductor, and a grounding conductor, said device comprising: a hot line connecting said hot conductor of said electrical service to said hot wire of said appliance electrical connection; a neutral line connecting said neutral conductor of said electrical service to said neutral wire of said appliance electrical connection; a grounding line connected to said grounding wire of said appliance electrical connection and to said grounding conductor of said electrical service; current-flow-interrupting means serially connected to said grounding line for opening the hot line responsive to the flow of leakage current along the grounding line due to the existence of a ground fault in said appliance; said current-flow-interrupting means comprising a normallyclosed relay switch in said hot line, said relay switch being opened by an electromagnet serially connected between said grounding line and said grounding conductor of said electrical service.
Claim 3
Independent Claim
210 words
A device for use with an electrical appliance having a grounded frame and including an electrical connection having a hot wire, neutral wire, and a grounding wire connected to said frame, said electrical connection being connected to an electrical service consisting of a hot conductor and at least one return conductor means, said device comprising: a hot line connecting said hot conductor of said electrical service to said hot wire of said appliance electrical connection; a neutral line connecting said return conductor means of said electrical service to said neutral wire of said appliance electrical connection; a grounding line connected to said grounding wire of said appliance electrical connection and to said return conductor means of said electrical service; current-flow-detecting means serially connected to said grounding line for detecting the flow of leakage along the grounding line due to the existence of an electrical path from said hot wire to said appliance frame; said current-flow-detecting means including a relay switch actuated by the flow of leakage current along said grounding line to open the circuit of said hot line, thereby interrupting the flow of current along said hot line to said appliance; and means actuated by an excessive overload current flow through said hot line to energize said relay switch.
Claim 4
Independent Claim
210 words
A device for use with an electrical appliance having a grounded frame and including an electrical connection having a hot wire, neutral wire, and a grounding wire connected to said frame, said electrical connection being connected to an electrical service consisting of a hot conductor and at least one return conductor means, said device comprising: a hot line connecting said hot conductor of said electrical service to said hot wire of said appliance electrical connection; a neutral line connecting said return conductor means of said electrical service to said neutral wire of said appliance electrical connection; a grounding line connected to said grounding wire of said appliance electrical connection and to said return conductor means of said electrical service; current-flow-detecting means serially connected to said grounding line for detecting the flow of leakage along the grounding line due to the existence of an electrical path from said hot wire to said appliance frame; said current-flow-detecting means including a relay switch actuated by the flow of leakage current along said grounding line to open the circuit of said hot line, thereby interrupting the flow of current along said hot line to said appliance; and means actuated by an excessive overload current flow through said hot line to energize said relay switch.
Claim 5
Dependent Claim
70 words
A device as in claim 2, wherein the last-named means comprises a second relay switch having normally open contacts connected to said hot line and to said first-named relay switch, respectively, said second relay switch being operable to close said normally open contacts and thereby send current from said hot line to said first-named relay switch, so as to actuate the latter and open the hot line to said appliance.
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) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |