Dual Rate Magnet Return Spring
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
When a magnet is energized to pull the armature 12 into engagement with yoke 14, extension spring 10 is tensioned to provide a restoring force. Under normal circumstances residual magnetism between the armature 12 and yoke 14 will cause the armature to remain sealed for a short period of time after the relaxation of the magnetic field. Then and only then, after the residual magnetism has diminished, will the force of spring 10 be sufficient to break the seal and allow armature 12 to restore. A technique for overcoming this residual magnetism and to improve the drop time is disclosed in Figs. 1 and 2.