Magnetic latch device for a clapper type contactor
US4173004A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 25, 1978 |
| Grant date | Oct 30, 1979 |
| Priority date | — |
| Expiry date | Jul 25, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H71/2472
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A magnetic latch for a clapper type contactor having an electromechanical system comprising an operating coil, a coil core, a magnet frame, and an armature includes a magnetic latch plate. The magnetic latch plate includes a stop portion having a pair of ears mounted on a pivoted contact arm. The stop portion of the latch abuts against the magnet frame before energization of the coil so that a flux path includes the core, the magnet frame, the magnetic latch, the armature and the air gap between the armature and core of the coil. After the coil is energized and the current begins to build the magnetic latch saturates an additional parallel flux path travels from the core to the magnet frame through the heel air gap of the armature through the armature to the air gap between the armature and core of the coil until the combined force across the heel air gap and the air gap between the magnet frame and armature and the armature and the core, respectively, are greater than the force between the magnet frame and the magnetic latch, then the armature closes against the core. The amount of latch force desired is controlled by adjusting the cross-sectional area of the magnetic latch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.