Patent ID: 6715732
Filing Date: 2004-04-06
Classification: F16K,G05D,H01F

Abstract:
A device comprising:a solenoid coil having a longitudinal axis and a bore coaxial therewith, and being operative to produce a magnetic field; a housing for said solenoid coil and containing magnetic material for a flux path of said magnetic field produced by said solenoid, and including an interior radial projection; a magnetic pole piece protruding from said coaxial bore of said solenoid coil; and a magnetic armature that is axially translatable relative to said magnetic pole piece and having a tapered projection portion that contains an interior recess of a diameter slightly larger than an outer diameter of said protruding end of said magnetic pole piece and forms with said protruding end of said magnetic pole piece, an axial gap that is effective to substantially reduce an axial magnetic flux path between said armature and said magnetic pole piece, and a first generally cylindrical gap that is radially magnetically coupled with said protruding end of said magnetic pole piece, and a rim portion that forms a second generally cylindrical gap that is radially magnetically coupled with said radial projection of said housing, so that, during relative axial translation between said tapered projection portion of said armature and said magnetic pole piece, and during relative axial translation between said rim portion of said armature and said radial projection of said housing, magnetic flux is directed in a radial direction across said first and second generally cylindrical gaps, by-passing said axial gap; said first and second generally cylindrical gaps define air-bushings for said magnetic armature so that said device is devoid of frictional engagement bushings for said magnetic armature.