Patent ID: 6224033
Filing Date: 2001-05-01
Classification: F16K,G05D,H01F

Abstract:
A proportional solenoid assembly comprising:a solenoid coil having a longitudinal axis and a bore coaxial therewith, and being operative to produce a magnetic field;a housing in which said solenoid coil is placed, said housing containing magnetic material for providing a flux path for said magnetic field produced by said solenoid, and including a radial projection toward an interior portion of said housing;a magnetic pole piece disposed within and having a protrusion end of a diameter no greater than the diameter of and protruding from said coaxial bore of said solenoid coil; anda movable armature of magnetic material, supported for axial translation relative to said magnetic pole piece and having a projection portion that contains an interior recess of a diameter slightly larger than an outer diameter of said protrusion end of said magnetic pole piece and forming, with said protrusion end of said magnetic pole piece, a first axial gap that is effective to minimize an axial magnetic flux path between said moveable armature and said magnetic pole piece, and a second, generally cylindrical gap radially magnetically coupled with said protrusion end of said magnetic pole piece, and a rim portion forming a third, generally cylindrical gap radially magnetically coupled with said radial projection of said housing, such that, during relative axial translation between said projection portion of said movable armature and said magnetic pole piece, and during relative axial translation between said rim portion of said movable armature and said radial projection of said housing, magnetic flux is directed in a radial direction across said second and third cylindrical gaps, by-passing said first axial gap, and wherein a distal end of said projection portion is tapered.