04988074 is referenced by 104 patents and cites 44 patents.

A proportional variable force solenoid control valve with an armature reciprocably movable within the bore hole of a coreless solenoid bobbin in proportion to applied electrical current between positions corresponding to a closed valve position and a fully open position. The positioning of the armature is controlled by balancing the variable force of the magnetic field of the coreless solenoid plus the force of the magnetic field of a permanent ring magnet against the force of a coil spring which biases the valve toward the closed position. The armature is suspended by low spring rate plate springs on opposite ends of the armature. An elastomeric diaphragm seals the solenoid against contaminants. The force of the coil spring is adjusted by a threaded plug.

Title
Proportional variable force solenoid control valve
Application Number
7/194787
Publication Number
4988074
Application Date
May 17, 1988
Publication Date
January 29, 1991
Inventor
Hamid Najmolhoda
Grandville
MI, US
Agent
Malcolm L Sutherland
Leon E Redman
Assignee
Hi Ram
MI, US
IPC
H01F 7/08
F16K 31/08
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