US5077626A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase-failure detectors responsive to unequal bending of bi-metal members
Assignee: Sellafield Ltd
•
Filing: 1990-04-02
•
Granted: 1991-12-31
•
Expires: 2010-04-02
Abstract
Abstract Circuit breakers can be used to replace fuses in plant comprising centrifuge machines driven by small three-phase electric motors. The circuit breakers incorporate three bi-metal strips which bend due to the heat produced by current flow. Loss of current in one phase results in unequal bending of these trips. In one arrangement, a light-emitting diode 5 fitted to a first strip 2 produced light to pass through an aperture 8 in a plate 7 on the second strip 3 to fall on a photo-sensitive detector 6 on the third strip 4. Any unequal bending causes the light to be cut-off and the resulting signal can be used to trip the circuit breaker. In some cases the strips are the strips in the circuit breaker.
Inventors
- 👤 John Barnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:57
CPC Classifications
H; H02; H02H; H02H1/00; H02H1/0061; H02H1/0069; H01; H01H; H01H83/00; H01H83/14; H01H83/142
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
70 words
A phase-failure detector comprising three bi-metal strips, and means mounted on the strips for detecting unequal bending in the strips arising from loss of current in a phase and arranged to provide a signal, in which the detecting means comprises a light source and a light detector respectively mounted on two of the strips, and an apertured plate between the source and the detector and mounted on the third strip.
Claim 2
Dependent Claim
70 words
A phase-failure detector comprising three bi-metal strips, and means mounted on the strips for detecting unequal bending in the strips arising from loss of current in a phase and arranged to provide a signal, in which the detecting means comprises a light source and a light detector respectively mounted on two of the strips, and an apertured plate between the source and the detector and mounted on the third strip.
Claim 3
Dependent Claim
23 words
A detector as claimed in claim 1, in electrical connection with a circuit breaker, the signal being operative to trip the circuit breaker.
Claim 4
Dependent Claim
34 words
A detector as claimed in claim 1, in electrical connection with a circuit breaker having a trip mechanism and, a trip detector circuit electrically connected to receive the signal and energise the trip mechanism.
References Cited (Backward Citations)
US3949219A
Cited
US4379968A
Cited
US4475098A
Cited
US4723190A
Cited
US4979069A
Cited
US4692612A
Cited
US4831253A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |