04954799 is referenced by 157 patents and cites 6 patents.

A rectilinear motion proportional solenoid assembly includes a cylindrical housing containing an electromagnetic coil having a longitudinal coaxial bore. The housing contains maagnetic material for providing a flux path for the magnetic field produced by the coil. A generally cylindrical magnetic pole piece element is inserted into the bore and a movable armature assembly of magnetic material is supported within the bore for movement along the longitudinal axis of the coil by a pair of thin, flexible suspension springs. One of the springs is located within the bore adjacent to one end of the magnetic pole piece whereat an axial gap between the pole piece and the armature is formed. A second spring is located within the housing within the vicinity of a radial air gap between the armature and the housing. The pole piece contains an auxiliary region adjacent to the axial air gap for shunting a portion of the axially directed magnetic flux, for effectively causing the force imparted to the movable armature by the application of a current to the electromagnetic coil to be substantially constant irrespective of the magnitude of the axial gap for a variation in the axial gap over a prescribed range.

Title
Proportional electropneumatic solenoid-controlled valve
Application Number
7/360429
Publication Number
4954799
Application Date
June 2, 1989
Publication Date
September 4, 1990
Inventor
Viraraghavan S Kumar
Palm Bay
FL, US
Agent
Evenson Wands Edwards Lenahan & McKeown
Assignee
Puritan Bennett Corporation
KS, US
IPC
F16K 31/06
H01F 7/13
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