Molded case circuit breaker with a movable electrical contact positioned by a camming leaf spring
US4645890A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1985 |
| Grant date | Feb 24, 1987 |
| Priority date | — |
| Expiry date | Jul 19, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H77/104
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A molded case circuit breaker includes a movable upper electrical contact carried by a contact member having an end portion with an arcuate cam surface formed thereon for engaging an outwardly projecting cam surface of a leaf spring. The leaf spring is secured to and disposed around an enlarged portion of a rotatable cross-bar of the operating mechanism of the circuit breaker. The leaf spring has an outwardly protruding cam surface and is mechanically configured to provide sufficient biasing force to the end portion of the movable upper electrical contact member to enable the upper electrical contact member and upper contact to move in unison with the cross-bar during normal operation of the breaker. Upon the occurrence of a high level short circuit or fault current of sufficient magnitude, the upper electrical contact rotate member and upper and the arcuate cam surface thereof is moved against the then stationary cam surface of the leaf spring. The arcuate cam surface of the leaf spring and the arcuate cam surface of the end portion of the contact member are configured to provide decreased biasing force as the upper electrical contact member rotates to its BLOWN-OPEN position. A d…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.