Patent US4175255A successfully refreshed from Google Patents.
US4175255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device to protect against flow of current
Assignee: Individual
•
Filing: 1977-09-06
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Granted: 1979-11-20
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Expires: 1997-09-06
Abstract
Abstract A protective device to interrupt the flow of current at a work place when current of a magnitude to endanger life flows through the body of a person whereby at least two electrodes with skin contact are applied on a person which electrodes are connected to a voltage sensor which determines the voltage difference between the electrodes when current flows through the body and is designed to release a signal to a circuit breaking device which interrupts the flow of current when the current passing through the body exceeds the admissible value.
Inventors
- 👤 Sven N. J. Linnman
- 👤 Peter Isoz
- 👤 Nils P. Branderud
- 👤 Per E. C. Udden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:34
CPC Classifications
H; H02; H02H; H02H1/00; H02H1/0061; H02H1/0069; H02H3/00; H02H3/16; H02H5/00; H02H5/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
120 words
A protective device to interrupt the flow of current at a work place when current of a magnitude to endanger life flows through the body of a user comprising: at least two electrodes with skin contact for application to the body of a user; a voltage sensor connected to the electrodes for determining the voltage difference between the electrodes when a current flows through the body of the user and generating a signal when the voltage difference exceeds a given limit value; a circuit breaking device spaced from the voltage sensor and responsive to the signal for interrupting the flow of current; and a test oscillator for emitting intermittent voltage impulses through the electrodes to the body of the user.
Claim 2
Dependent Claim
120 words
A protective device to interrupt the flow of current at a work place when current of a magnitude to endanger life flows through the body of a user comprising: at least two electrodes with skin contact for application to the body of a user; a voltage sensor connected to the electrodes for determining the voltage difference between the electrodes when a current flows through the body of the user and generating a signal when the voltage difference exceeds a given limit value; a circuit breaking device spaced from the voltage sensor and responsive to the signal for interrupting the flow of current; and a test oscillator for emitting intermittent voltage impulses through the electrodes to the body of the user.
Claim 3
Dependent Claim
13 words
A device according to claim 1 wherein the voltage sensor comprises an exclusive-OR-gate.
Claim 4
Dependent Claim
53 words
A device according to claim 1 including: a flash unit connected to the voltage sensor and operated by the voltage sensor for releasing a flash of light; and a photoelectric cell connected between the flash unit and the circuit breaking device for detecting the flash of light to activate the circuit breaking device.
Claim 5
Dependent Claim
15 words
A device according to claim 1 including: in interference filter connected to the voltage sensor.
Claim 6
Dependent Claim
29 words
A device according to claim 1 wherein the signal is transmitted by the voltage sensor to the circuit breaking device by means of a wire, sound or radio connection.
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) | 1982-11-19 | 1983-05-21 | 1983-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-19 | 1987-05-21 | 1987-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-19 | 1991-05-21 | 1991-11-20 | $7700.00 | Window Closed / Lapsed |