Load break switch with safety mechanism
US4645888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1985 |
| Grant date | Feb 24, 1987 |
| Priority date | — |
| Expiry date | Dec 17, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H33/56
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A single-phase ground enclosed load break switch for distribution voltages has a hermetically sealed cylindrical metal housing of from 2 to 6 inches diameter which contains an insulating gas under pressure. The switch has a movable contact assembly to contact a pair of opposed stationary coaxial conductors within the housing. A rocking bellows at the fulcrum of a crank actuator provides a compact hermetic seal for the actuator without excessive strain of the bellows. A safety interlock with a visual indicator locks the contact assembly in case of a loss of pressure. Excessive pressure in the switch causes the bellows to be punctured with consequent locking of the contact assembly. The switch is small enough to be mounted directly on a transformer or placed into a cable, without the need for a separate enclosure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.