US4518913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measuring probes
Assignee: HEME INTERNATIONAL LIMITD A CORP OF GREAT BRITAIN
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Filing: 1982-05-18
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Granted: 1985-05-21
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Expires: 2002-05-18
Abstract
Abstract A "clip-on" probe for measuring electric currents by operation of the Hall effect comprises a ring of magnetizable material, at least part of which is mounted in a set of opposed jaws (4,5). The jaws are movable between an open position in which the jaws can be placed over a conductor and a closed position in which the jaws meet around the conductor and the ring is substantially complete. To facilitate removal of the probe when a heavy current is flowing through a conductor between the jaws, the jaws are provided with an opening mechanism with an actuator (7) so constructed and arranged that initial pressure on the actuator urges the jaws (4,5) apart from the closed position at a first mechanical advantage and, after an initial movement of the actuator, subsequent pressure urges the jaws towards the fully open position at a second lower mechanical advantage.
Inventors
- 👤 Rodney P. Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:49
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/20; G01R15/202; G01R1/00; G01R1/20; G01R1/22; G01R19/00; G01R19/145; G01R19/15
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
173 words
A measuring probe of the kind in which a substantially complete ring or magnetisable material is formed around a conductor, said probe comprising: a set of opposed jaws of magetisable material mounted to be relatively movable between an open position in which the ring is broken and the jaws can be placed over a conductor, and a closed position in which the jaws meet around the conductor and the ring of magnetisable material is at least substantially complete; an opening mechanism for said jaws with an actuator; means coupling said mechanism to at least one of said jaws to actuate said jaws to said open position, said mechanism including leverage means constructed such that initial pressure on said actuator urges said jaws apart from said closed position at a first mechanical advantage and, after initial movement of said actuator, subsequent pressure on said actuator urges said jaws toward said open position at a second lower mechanical advantage, the ratio of said first mechanical advantage to said second mechanical advantage being at least 3:1.
Claim 2
Dependent Claim
173 words
A measuring probe of the kind in which a substantially complete ring or magnetisable material is formed around a conductor, said probe comprising: a set of opposed jaws of magetisable material mounted to be relatively movable between an open position in which the ring is broken and the jaws can be placed over a conductor, and a closed position in which the jaws meet around the conductor and the ring of magnetisable material is at least substantially complete; an opening mechanism for said jaws with an actuator; means coupling said mechanism to at least one of said jaws to actuate said jaws to said open position, said mechanism including leverage means constructed such that initial pressure on said actuator urges said jaws apart from said closed position at a first mechanical advantage and, after initial movement of said actuator, subsequent pressure on said actuator urges said jaws toward said open position at a second lower mechanical advantage, the ratio of said first mechanical advantage to said second mechanical advantage being at least 3:1.
Claim 3
Dependent Claim
27 words
A measuring probe as claimed in claim 1 in which one of the jaws is pivotally mounted for movement between said closed position and said open position.
Claim 4
Dependent Claim
32 words
A measuring probe as claimed in claim 1 in which initial pressure on the actuator is transferred to the said one jaw via a pivotally mounted crank included in said leverage means.
Claim 5
Dependent Claim
64 words
A measuring probe as claimed in claim 1 in which one of the jaws is pivotally mounted for movement between a closed position and an open position and in which initial pressure on the actuator is transferred to the said jaw via a pivotally mounted crank included in said leverage means, the said jaw and crank being mounted to pivot on a common axis.
Claim 6
Dependent Claim
40 words
A measuring probe as claimed in claim 1 in which said actuator bears directly on said one jaw after initial movement of said actuator to urge said one jaw towards the fully open position at said second lower mechanical advantage.
Claim 7
Dependent Claim
27 words
A measuring probe as claimed in claim 5 in which one of said jaws is pivotally mounted for movement between a closed position and an open position.
Claim 8
Dependent Claim
47 words
A measuring probe as claimed in claim 5 in which one of said jaws is pivotally mounted for movement between a closed position and an open position, and in which initial pressure on the actuator is transferred to the said one jaw via a pivotally mounted crank.
Claim 9
Dependent Claim
80 words
A measuring probe as claimed in claim 1 which additionally comprises a Hall generator mounted in a gap in the ring of magnetisable material, first electrical connections for applying a potential difference across the Hall generator in a direction substantially perpendicular to the magnetic field from the ring, and second electrical connections to the Hall generator along a line substantially perpendicular to the direction of said magnetic field and the direction of a potential difference applied between said first connections.
Claim 10
Dependent Claim
44 words
A measuring instrument comprising a measuring probe as claimed in claim 1, means for generating a signal related to the magnetic field in the ring of magnetisable material in the probe, means for measuring the signal generated, and means for displaying the resulting measurement.
Claim 11
Dependent Claim
67 words
A measuring instrument comprising a measuring probe as claimed in claim 1 in which one of the jaws is pivotally mounted for movement between said closed position and said open position, and which further comprises means for generating a signal related to the magnetic field in the ring of magnetisable material in the probe, means for measuring the signal generated, and means for displaying the resulting measurements.
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) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |