US 6,737,946 B2Granted

Solenoid for efficient pull-in and quick landing

OwnerJoseph B. Seale, Gary E. Bergstrominventors

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Abstract

A solenoid with improved pull-in and landing characteristics. As a solenoid armature closes toward contact with the pole faces of a yoke, a geometric redistribution of a constant total flux causes the force to increase with decreasing gap. Latching force at saturation is maximized when the latching contact area matches the tightest bottleneck in the flux path. The addition of ferromagnetic area not making latching contact preserves the maximum latching force, increases power efficiency for pulling at a distance, and increases the flux redistribution effect of increasing force with decreasing gap at constant flux. The extra constant-flux force change at small gaps may be abrupt, for a high deceleration followed by a quick passive force increase to latch with low impact, or gradual, for tight servo control and very low impact. Conductive material can provide selective inductive damping near latching. Armature mass can be kept low despite the extra ferromagnetic area.

Claims17

Dependent claims

A dual-latching solenoid comprising a first ferromagnetic U-core yoke, a second ferromagnetic U-core yoke, and a ferromagnetic armature positioned to travel between said first yoke and said second yoke and arranged to be latched magnetically to either said first yoke or said second yoke, said armature having a center region and a non-center region adjacent to said center region and having a boundary therebetween and further including pathways that conduct induced current selectively in response to flux redistribution between said center region and said non-center region of said armature, wherein:

a. a surface of said first yoke includes one or more steps separating approximately axially facing poleface regions of said first yoke, wherein one or more of said poleface regions is configured to mate with said armature when said armature is latched to said first yoke;
b. said center region of said armature is thicker than said non-center region, wherein one of said one or more steps of said first yoke is near to and substantially parallel to said boundary of said armature when said armature is latched to said first yoke;
and
c when said armature is latched to said first yoke, said center region of said armature is in mating communication with one or more of said poleface regions of said first yoke while a gap remains between at least a portion of said non-center region and said first yoke.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 09/789,682Filed 21 Feb 2001 · us provisional application
Priority: 22 Feb 2000
Published: US 2002/0008603 A124 Jan 2002
Granted: 18 May 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H01F 7/1844
Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for…:…
F16K 31/0675
Using a magnet , e.g. diaphragm valves, cutting off by means of a liquid: electromagnet aspects, e.g. electric supply therefor
F16K 31/0679
Electromagnet aspects, e.g. electric supply therefor: with more than one energising coil
H01F 7/081
With armatures: magnetic constructions