US5136456A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Faulted current indicator with protection against temporary overloads and transients
Assignee: Pacific Scientific Co
•
Filing: 1989-11-17
•
Granted: 1992-08-04
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Expires: 2009-11-17
Abstract
Abstract The disclosed faulted current indicator ignores temporary overloads and transients by inhibiting any trip resulting from an overcurrent signal until a disabling circuit senses that a fuse or circuit breaker has reduced the line current to zero.
Inventors
- 👤 Thomas Yeh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:44
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/02; H02H3/04; H02H3/042; H02H1/00; H02H1/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
94 words
A faulted current indicator, comprising: reset means for producing a reset signal in response to a first current value in a cable; trip means for producing a trip signal in response to a second current value higher than the first current value in the cable; disabling means coupled to said trip means for producing a signal to enable said trip means to produce the trip signal when the current in the cable drops below the first current value within a given time after reaching the second current value and disable the trip signal otherwise.
Claim 2
Dependent Claim
94 words
A faulted current indicator, comprising: reset means for producing a reset signal in response to a first current value in a cable; trip means for producing a trip signal in response to a second current value higher than the first current value in the cable; disabling means coupled to said trip means for producing a signal to enable said trip means to produce the trip signal when the current in the cable drops below the first current value within a given time after reaching the second current value and disable the trip signal otherwise.
Claim 3
Dependent Claim
36 words
An indicator as in claim 1, wherein: said trip means includes means to maintain the trip signal longer than the time the current drops from above the second current value to below the first current value.
Claim 4
Dependent Claim
39 words
An indicator as in claim 1, wherein: said disabling means enables said trip means to produce the trip signal when the current in the cable drops from the second value to a value substantially zero within the given time.
Claim 5
Dependent Claim
26 words
A faulted current indicator as in claim 1, wherein: said disabling means includes inrush restraint means for disabling said trip means in response to current inrushes.
Claim 6
Dependent Claim
143 words
A faulted current indicator, comprising: reset means for producing a reset signal in response to a first current value in a cable; signal producing means for producing a signal in response to the cable exceeding a second current value higher than the first current value in the cable; distinguishing means coupled to said indicting means and current in the cable for distinguishing between the indications followed by current in the cable dropping below the first current value within a given time and indications followed by current in the cable failing to drop below the first current value within the given time; and trip signal means responsive to said distinguishing means for producing trip signals only in response to indications followed by cable currents dropping below the first current value within the given time, and for disabling the trip signals at all other times.
Claim 7
Dependent Claim
143 words
A faulted current indicator, comprising: reset means for producing a reset signal in response to a first current value in a cable; signal producing means for producing a signal in response to the cable exceeding a second current value higher than the first current value in the cable; distinguishing means coupled to said indicting means and current in the cable for distinguishing between the indications followed by current in the cable dropping below the first current value within a given time and indications followed by current in the cable failing to drop below the first current value within the given time; and trip signal means responsive to said distinguishing means for producing trip signals only in response to indications followed by cable currents dropping below the first current value within the given time, and for disabling the trip signals at all other times.
Claim 8
Dependent Claim
36 words
A faulted current indicator as in claim 5 wherein: said distinguishing means further includes inrush restraint means for preventing said trip signal means from producing a trip signal when said indicating means responds to current inrushes.
Claim 9
Dependent Claim
35 words
An indicator as in claim 5, wherein: said indicating means includes means to maintain the indication longer than the time the current drops from above the second current value to below the first current value.
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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) | 1995-08-04 | 1996-02-03 | 1996-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-04 | 2000-02-03 | 2000-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-04 | 2004-02-03 | 2004-08-04 | $7700.00 | Window Closed / Lapsed |