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US 5,294,902 AGranted
Fail-safe residential circuit breaker
AssigneeGeneral Electric Company
InventorsErich J. Pannenborg, Joseph M. Palmieri, Raymond K. Seymour
Life of this patent
Estimating the term…
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.
Claims7
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.
4 more elements
Dependencies are inferred from the claim text.