Patent US5294902A successfully refreshed from Google Patents.
US5294902A
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US
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Fail-safe residential circuit breaker
Assignee: MENELLY RICHARD A ESQ
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Filing: 1993-06-14
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Granted: 1994-03-15
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Expires: 2013-06-14
Abstract
Abstract A molded case circuit breaker for residential use employs an additional safety feature to ensure a fail-safe condition in the event that the circuit breaker is installed within a circuit that may be subjected to an excessive over-current fault that disables the circuit breaker trip unit. The integral bimetal-fuse within the circuit breaker trip unit responds to interrupt circuit current before any damage can occur to the associated electrical wiring system.
Inventors
- 👤 Erich J. Pannenborg
- 👤 Joseph M. Palmieri
- 👤 Raymond K. Seymour
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:17
CPC Classifications
H; H01; H01H; H01H21/00; H01H21/02; H01H21/18; H01H21/20; H01H47/00; H01H47/002; H01H71/00; H01H71/10; H01H71/12; H01H71/40
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
156 words
A molded case circuit breaker having a fail safe thermal-magnetic trip unit comprising: a molded plastic case attached to a molded plastic cover; an operating mechanism arranged within said case for interrupting current through a protected circuit upon the occurrence of an overcurrent condition; a pivotally-mounted operating cradle interacting with said operating mechanism by means of a shaped end; a magnetically-responsive armature latch having an opening receiving said shaped end and retaining said operating mechanism from interrupting current under quiescent current conditions; a thermal-magnetic trip unit within said case arranged for articulating said operating mechanism by moving said cradle away from said latch opening upon occurrence of an overcurrent condition within a range of predetermined values; and a combined bimetal-fuse element within said trip unit, said element having a reduced dimension to provide a region of increased current density whereby said element melts to interrupt current when said overcurrent condition exceeds a range of predetermined values.
Claim 2
Dependent Claim
156 words
A molded case circuit breaker having a fail safe thermal-magnetic trip unit comprising: a molded plastic case attached to a molded plastic cover; an operating mechanism arranged within said case for interrupting current through a protected circuit upon the occurrence of an overcurrent condition; a pivotally-mounted operating cradle interacting with said operating mechanism by means of a shaped end; a magnetically-responsive armature latch having an opening receiving said shaped end and retaining said operating mechanism from interrupting current under quiescent current conditions; a thermal-magnetic trip unit within said case arranged for articulating said operating mechanism by moving said cradle away from said latch opening upon occurrence of an overcurrent condition within a range of predetermined values; and a combined bimetal-fuse element within said trip unit, said element having a reduced dimension to provide a region of increased current density whereby said element melts to interrupt current when said overcurrent condition exceeds a range of predetermined values.
Claim 3
Dependent Claim
37 words
The molded case circuit breaker of claim 1 wherein said element comprises a thermal-responsive plate of a defined length, thickness and width, said width being reduced in one region to provide said region of increased current density.
Claim 4
Dependent Claim
37 words
The molded case circuit breaker of claim 1 wherein said element comprises a thermal-responsive plate of a defined length, thickness and width, said thickness being reduced in one region to provide said region of increased current density.
Claim 5
Dependent Claim
33 words
The molded case circuit breaker of claim 1 wherein said element comprises a thermal-responsive plate having a slot on one edge thereof to provide said region of increased current density proximate said slot.
Claim 6
Dependent Claim
31 words
The molded case circuit breaker of claim 1 wherein said element comprises a thermal-responsive plate having a thru-hole formed therein to provide said region of increased current density proximate said thru-hole.
Claim 7
Dependent Claim
33 words
The molded case circuit breaker of claim 1 wherein said element comprises a thermal-responsive plate having a depression formed on one surface to provide said region of increased current density within said depression.
Claim 8
Dependent Claim
33 words
The molded case circuit breaker of claim 1 wherein said element comprises a thermal-responsive plate having a groove formed therein extending across said plate to thereby provide said region of increased current density.
References Cited (Backward Citations)
US3796930A
Cited
US4513268A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-14 | 1997-09-13 | 1998-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-14 | 2001-09-13 | 2002-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-14 | 2005-09-13 | 2006-03-15 | $7700.00 | Window Closed / Lapsed |