Molded case current limiting circuit breaker
US5341191A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1991 |
| Grant date | Aug 23, 1994 |
| Priority date | — |
| Expiry date | Oct 18, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2009/305
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A molded case circuit breaker having current limiting capabilities optimized for relatively smaller frame sizes. More specifically, one aspect of the invention relates to a two-piece carrier assembly for carrying the main and arcing contact arms which allows the main and arcing contacts to be blown open during short circuit conditions. The two-piece carrier assembly includes an inner carrier and an outer carrier pivotally connected together. The contact arms are carried by the inner carrier. When sufficient magnetic repulsion forces are exerted on the contacts due to a short circuit condition, the inner carrier pivots relative to the outer carrier to allow the contact arms to blow open. In order to control the amount of force required for blow open, a compression spring loaded cam assembly is provided. Another important aspect of the invention relates to a contact spring housing which relocates the contact springs away from the separable contacts to protect the springs from damage, for example, from heat due to contact separation. In order to improve the interruption time of the circuit breaker for relatively large overcurrents, such as a short circuit, a reverse current loop is pr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.