Solenoid
US4880999A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1989 |
| Grant date | Nov 14, 1989 |
| Priority date | — |
| Expiry date | Mar 7, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/145
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A solenoid has a coil with an outer core and an inner core. The cores provide the magnetic circuit around the coil. The inner core includes a rotor which has radially extending armatures. The armatures are positioned in gaps between radially extending poles of the outer core so as to form air gaps between the poles and the armatures. When the coil is energized, the armatures are attracted to the poles and cause the rotor to rotate, thereby closing the air gaps. The shaft is coupled to the rotor through a drive mechanism so as to rotate with the rotor. The shaft is made of a material with a relatively high magnetic permeability, as are the inner and outer cores, so that the shaft is magnetically coupled to the inner core rotor. When the rotor stops rotating, the shaft also stops. A return spring returns the rotor to its deenergized position when the coil is deenergized, recreating the air gaps. The drive mechanism allows the shaft to remain stationary while the rotors return to the deenergized position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.