Patent ID: 7021603
Filing Date: 2006-04-04
Classification: F16K,H01F,H01H,Y10T

Abstract:
1. A magnetic drive for a fluid flow control valve comprising permanent magnet means generating magnetic flux between pairs of poles, an armature mounted for movement enabling said armature to occupy either a rest position in a first air gap between one pair of poles in which the flux is in one direction, or a rest position in a second air gap between another pair of poles in which the flux is in the opposite direction, with a region of flux cancellation between the two air gaps, and at least one electromagnet winding having an axis generally perpendicular to the path of movement of the armature to which current can be supplied to produce a magnetic flux in said one direction or the other, depending on the direction of the current, the flux from the winding increasing the flux density in the other air gap, thereby effectively shifting the flux cancellation region towards or into one of the two air gaps so as to produce a flux density gradient extending from one air gap to the other which will cause the armature to move into (or remain in) the air gap having the higher flux density, in which the armature will continue to remain after the current flow ceases, and wherein energy storing means is provided engagable by the armature at one end of the armature travel which is only engaged as the armature approaches said armature's rest position, thereby to absorb energy from the final movement of the armature into said armature's rest position at that end, of said armature's travel.