Patent US4797649A successfully refreshed from Google Patents.
US4797649A
Expired / Lapsed
US
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Circuit breaker actuated by shape memory alloy
Assignee: Individual
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Filing: 1987-11-17
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Granted: 1989-01-10
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Expires: 2007-11-17
Abstract
Abstract A circuit breaker includes first and second contactors having connecting/disconnecting means which normally keeps the two contactors in contact with each other. A shape memory alloy is mechanically connected to a predetermined portion of one of the connecting/disconnecting means of one contactor is electrically connected in parallel with a device to be protected, e.g. an electric circuit or an electric element. When a voltage of a predetermined value or more is applied to the device being protected, a current of a predetermined value or more passes through the shape memory alloy, whereby the alloy is heated to produce its shape memory effect. A shape recovering force is applied to the connecting/disconnecting means of the on contactor in a predetermined direction to separate the contactors.
Inventors
- 👤 Dai Homma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:34
CPC Classifications
H; H01; H01H; H01H71/00; H01H71/10; H01H71/12; H01H71/14; H01H71/145; H01H83/00; H01H83/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
100 words
A circuit breaker for protecting an electrical device comprising: a first and a second contactor having respective connecting/disconnecting means for normally keeping said first and second contactors in contact with each other, and for continuously separating said first and second contactors from each other when a mechanical force of a predetermined value is applied to said means in a predetermined direction; and a shape memory alloy electrically connected in parallel with said device being protected, said alloy further being mechanically coupled to said means for applying said force in said predetermined direction when the shape memory effect is generated therein.
Claim 2
Dependent Claim
100 words
A circuit breaker for protecting an electrical device comprising: a first and a second contactor having respective connecting/disconnecting means for normally keeping said first and second contactors in contact with each other, and for continuously separating said first and second contactors from each other when a mechanical force of a predetermined value is applied to said means in a predetermined direction; and a shape memory alloy electrically connected in parallel with said device being protected, said alloy further being mechanically coupled to said means for applying said force in said predetermined direction when the shape memory effect is generated therein.
Claim 3
Dependent Claim
43 words
A circuit breaker as recited in claim 1, wherein said shape memory alloy is of a wire shape, and when said first and second contactors are in contact with each other, said shape memory alloy receives an elongation from an original memory length.
Claim 4
Dependent Claim
134 words
A circuit breaker as recited in claim 1, wherein: said connecting/disconnecting means of said first contactor comprises a leaf spring member, and wherein one end portion thereof forms a free end curved to form a hook portion; said connecting/disconnecting means of said second contactor comprises another leaf spring member, one end portion thereof forming a free end including an engageable slot thereat, said engageable slot being engageable with said hook portion of said first contactor in a state where said first and second contactors are elastically deformed; and when said engageable slot is engaged with said hook portion, if said force in said predetermined direction is applied to said leaf spring member of said first contactor by said shape memory alloy, then said engageable slot and said hook portion are disengaged from each other.
Claim 5
Dependent Claim
67 words
A circuit breaker as recited in claim 3, wherein: said shape memory alloy is of a wire shape, one end of which is mechanically and electrically connected to said leaf spring member of said first contactor; and when the hook portion of said first contactor is engaged with said engageable slot of said second contactor, said shape memory alloy receives an elongation from an original memory length.
Claim 6
Dependent Claim
31 words
A circuit breaker as recited in claim 1, wherein an impedance of said shape memory alloy is set at a value relatively higher than an impedance of said device being protected.
Claim 7
Dependent Claim
17 words
A circuit breaker as recited in claim 1, wherein said subject to be protected is a fuse.
Claim 8
Dependent Claim
19 words
A circuit breaker as recited in claim 1, wherein said shape memory alloy is formed of a Ti--Ni alloy.
References Cited (Backward Citations)
US3858141A
Cited
US4544988A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-10 | 1992-07-11 | 1993-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-10 | 1996-07-11 | 1997-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-10 | 2000-07-11 | 2001-01-10 | $7700.00 | Window Closed / Lapsed |