Electromagnetic relay and the manufacture thereof
US4075585A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Dec 10, 1975 |
| Grant date | Feb 21, 1978 |
| Priority date | — |
| Expiry date | Dec 10, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2001/545
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electromagnetic relay comprises a coil bobbin of plastic material defining a protective tube, a contact chamber and a magnet chamber which together form a space that extends the entire length of the bobbin and is initially open at both ends. A permanent magnet is disposed in the magnet chamber, serving to seal one end of the space. This magnet has a surface exposed to the contact chamber and is made of a material activatable as a getter. A contact actuator is mounted to extend along the protective tube with a free end extending into the contact chamber. A pair of pole shoes each have a first end in proximity to the permanent magnet and a second end extending into the contact chamber. These second ends form fixed contacts for cooperation with the free end of the contact actuator. After assembly of these parts the space is subjected to a vacuum and an elevated temperature to drive off moisture and activate the getter. The vacuum is then replaced with an atmosphere of a protective gas, and the other end of the space is sealed with a closure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.