Patent US5034726A successfully refreshed from Google Patents.
US5034726A
Expired / Lapsed
US
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Portable ground fault detector
Assignee: Valvoline Oil and Chemicals Ltd
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Filing: 1990-03-06
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Granted: 1991-07-23
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Expires: 2010-03-06
Abstract
Abstract A portable ground fault detector for use on tanker trucks to provide visual and audible warning of unsafe conditions. Closing of a grounding circuit operating at low voltage permits energizing of a circuit to show safe grounding conditions and interruption of continuity of the grounding circuit provides visual and audible warning of unsafe conditions.
Inventors
- 👤 Roland R. Blondin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:28
CPC Classifications
H; H02; H02H; H02H5/00; H02H5/10; H02H5/105
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
159 words
A ground fault detecting device comprising, in combination, a first grounding clamp and a relay electrically connected in series to a battery power supply comprised of a pair of batteries in series and a second grounding clamp and a plurality of diodes electrically connected in series to said battery power supply, to form a grounding circuit through an article to be grounded; said relay having double throw switching means with a normally--open contact and a normally--closed contact, said switching means being electrically connected between said batteries; a warning circuit electrically connected in series to the battery power supply through the normally--closed contact of the relay--actuated switching means having signalling means to warn of a ground fault condition; and a safe indicating circuit electrically connected in series to the battery power supply through the normally--open contact of the relay--actuated switching means having signalling means to advise a grounded condition during energization of the relay and closing of said normally--open contact.
Claim 2
Dependent Claim
159 words
A ground fault detecting device comprising, in combination, a first grounding clamp and a relay electrically connected in series to a battery power supply comprised of a pair of batteries in series and a second grounding clamp and a plurality of diodes electrically connected in series to said battery power supply, to form a grounding circuit through an article to be grounded; said relay having double throw switching means with a normally--open contact and a normally--closed contact, said switching means being electrically connected between said batteries; a warning circuit electrically connected in series to the battery power supply through the normally--closed contact of the relay--actuated switching means having signalling means to warn of a ground fault condition; and a safe indicating circuit electrically connected in series to the battery power supply through the normally--open contact of the relay--actuated switching means having signalling means to advise a grounded condition during energization of the relay and closing of said normally--open contact.
Claim 3
Dependent Claim
25 words
A ground fault detecting device as claimed in claim 1 in which the safe indicating circuit has a pair of green light-emitting diodes in parallel.
Claim 4
Dependent Claim
50 words
A ground fault detecting device as claimed in claim 1 or 2 in which the warning circuit has a pair of red light emitting diodes and an audible alarm all connected in parallel with each other, and a diode in series with said red light emitting diodes and audible alarm.
Claim 5
Dependent Claim
27 words
A ground fault detecting device as claimed in claim 1 or 2, said warning and safe indicating circuits having a resistor in series to limit the current.
References Cited (Backward Citations)
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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) | 1994-07-22 | 1995-01-21 | 1995-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-22 | 1999-01-21 | 1999-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-22 | 2003-01-21 | 2003-07-23 | $7700.00 | Window Closed / Lapsed |