Solenoid
US4569504A · kind A · utility
Inventor
Key dates
| Filing date | May 20, 1983 |
| Grant date | Feb 11, 1986 |
| Priority date | — |
| Expiry date | May 20, 2003 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16K31/0675
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A solenoid which has a coil, a ferromagnetic core extending completely through the center of the coil and a ferromagnetic upper pole formed integrally with the core at the lower end of the coil. The upper pole having a diameter larger than the diameter of the core but smaller than the outer diameter of the coil. A plunger mounted for movement towards and away from the upper pole. The plunger is operably connected to a mass flow control valve and spring biased towards a closed position away from the upper pole. The plunger has a diameter greater than its length and a set of concentric cylindrical ridges extending downwardly to interleave with a corresponding set of upwardly extending concentric cylindrical ridges on a lower pole. An outer, square ferromagnetic casing completes the magnetic circuit by extending from the upper end of the core to the outer surface of the lower pole. The interleaving ridges provide a large surface area for transfer of magnetic flux from the lower pole to the plunger. Two non-magnetic disk springs act to bias the plunger toward closure of the valve, to prevent latching by stopping the plunger from too close an approach to the upper pole, and to hold the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.