US3569879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit breaker trip unit assembly with auxiliary time delay armature
Assignee: ITE Imperial Corp
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Filing: 1969-12-08
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Granted: 1971-03-09
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Expires: 1989-12-08
Abstract
Abstract A circuit breaker magnetic trip unit assembly including a magnet core adjacent a conductor in the circuit being protected; a main armature which is separated by a predetermined air gap from the pole faces of the magnet core; the pole faces magnetically attract the main armature when the magnetic flux across the air gap elevates sufficiently; a separately movable auxiliary armature spaced away from the pole faces of the magnet and movable toward the pole faces upon the occurrence of magnetic attraction insufficient to move the main armature but sufficient to move the auxiliary armature; the auxiliary armature including an abutment for engaging and shifting the main armature toward the pole faces as the auxiliary armature moves until the magnetic attraction on the main armature is sufficient to pull the main armature to the pole faces; and a time delay device slowing the movement of the auxiliary armature thereby delaying tripping caused by shifting of the auxiliary armature.
Inventors
- 👤 Carl E Gryctko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:24
CPC Classifications
H; H01; H01H; H01H71/00; H01H71/10; H01H71/12; H01H71/44
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
253 words
A circuit breaker trip unit assembly comprising: a magnet core comprised of material which concentrates magnetic flux in its vicinity, said core having pole faces; said core being positioned near a conductor in the circuit being protected by said trip unit assembly, whereby said core concentrates in its vicinity magnet flux surrounding the conductor; a main armature comprised of material which is attracted toward said magnet pole faces by magnetic flux in the vicinity of said core; said main armature being normally spaced away from said pole faces by a magnetic reluctance gap; a biasing means for normally biasing said main armature away from said pole faces and for permitting said main armature to move across said reluctance gap toward said pole faces upon the occurrence of a first fault current in the conductor of sufficient magnitude to attract said armature to said pole faces; means connected with said main armature to be moved by movement of said armature to bring about tripping of a circuit breaker connected with said trip unit assembly; magnetic reluctance adjustment means moving at a lower fault current than said first fault current with respect to said magnetic reluctance gap independently of said main armature to gradually reduce the reluctance of said gap until said main armature is attracted by said magnet core toward said pole faces; and a time delay device connected with said magnetic reluctance adjustment means for slowing the movement thereof thereby to provide a time delay in the operation of said trip unit assembly.
Claim 2
Dependent Claim
253 words
A circuit breaker trip unit assembly comprising: a magnet core comprised of material which concentrates magnetic flux in its vicinity, said core having pole faces; said core being positioned near a conductor in the circuit being protected by said trip unit assembly, whereby said core concentrates in its vicinity magnet flux surrounding the conductor; a main armature comprised of material which is attracted toward said magnet pole faces by magnetic flux in the vicinity of said core; said main armature being normally spaced away from said pole faces by a magnetic reluctance gap; a biasing means for normally biasing said main armature away from said pole faces and for permitting said main armature to move across said reluctance gap toward said pole faces upon the occurrence of a first fault current in the conductor of sufficient magnitude to attract said armature to said pole faces; means connected with said main armature to be moved by movement of said armature to bring about tripping of a circuit breaker connected with said trip unit assembly; magnetic reluctance adjustment means moving at a lower fault current than said first fault current with respect to said magnetic reluctance gap independently of said main armature to gradually reduce the reluctance of said gap until said main armature is attracted by said magnet core toward said pole faces; and a time delay device connected with said magnetic reluctance adjustment means for slowing the movement thereof thereby to provide a time delay in the operation of said trip unit assembly.
Claim 3
Dependent Claim
195 words
In the circuit breaker trip unit assembly of claim 1, the improvement furtHer comprising: said magnetic reluctance adjustment means comprising an auxiliary armature which is comprised of material that is attracted by magnetic flux concentrated in the vicinity of said magnet; said auxiliary armature being movable separately from said main armature; said auxiliary armature being normally spaced away from said pole faces; second biasing means for biasing said auxiliary armature away from said pole faces and for permitting said auxiliary armature to move toward said pole faces upon the occurrence of a fault current of sufficient magnitude in the conductor in the circuit being protected; both said auxiliary armature and said second biasing means for said auxiliary armature being chosen so that said auxiliary armature moves towards said pole faces at a lower fault current than would cause said main armature so to move; and said auxiliary armature being so positioned with respect to said main armature and said pole faces that the movement of said auxiliary armature toward said pole faces causes said auxiliary armature to so move with respect to said magnetic reluctance gap as to increasingly reduce the reluctance of said gap.
Claim 4
Dependent Claim
74 words
In the circuit breaker trip unit assembly of claim 2, the improvement further comprising; said auxiliary armature including abutment means for abutting said main armature upon said auxiliary armature moving toward said main armature, and once abutting, for causing said main armature to move toward said pole faces until the magnetic attraction on said main armature is sufficient to draw same to said pole faces independently of the force applied by said auxiliary armature.
Claim 5
Dependent Claim
46 words
In the circuit breaker trip unit assembly of claim 3, the improvement further comprising; first spacing means for establishing the initial spacing between said main and said auxiliary armatures and for holding them at their original spacing until said auxiliary armature moves toward said main armature.
Claim 6
Dependent Claim
46 words
In the circuit breaker trip unit assembly of claim 4, the improvement further comprising; said abutment means being adjustable in length such that said abutment means will contact said main armature only after said auxiliary armature has traveled a preselected adjustable distance toward said main armature.
Claim 7
Dependent Claim
70 words
In the circuit breaker trip unit assembly of claim 3, said magnet body being U-shaped and having a pole face at the end of each leg of the U; said auxiliary armature being U-shaped, having two arms extending toward said pole faces; said arms of said auxiliary armature extending sideways beyond the ends of said main armature, so as not to physically interfere with the movement of said main armature.
Claim 8
Dependent Claim
85 words
In combination with the trip unit assembly of claim 2, the improvement comprising: a circuit breaker, said circuit breaker having an electric circuit therethrough, cooperating contacts in said electric circuit, and an operating mechanism connected to said contacts for separating said contacts; said main armature of said trip unit assembly being connected to said circuit breaker operating mechanism for causing separation of said circuit breaker contacts as a result of movement of said main armature toward said magnet pole faces of said trip unit assembly.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |