Proportional valve

Claim 1

In a proportional fluid flow control valve having a valve body defining a flow chamber having an inlet and an outlet, a movable valve member in said chamber for adjustably controlling fluid flow through said valve chamber between said inlet and outlet, improved means for adjustably positioning said valve member, comprising: a solenoid tube having one end sealingly secured to said valve body in communication with said chamber and an opposite end; a solenoid armature movably disposed within said tube; means responsive to positioning of said armature for correspondingly positioning said valve member; an annular solenoid coil concentrically surrounding said solenoid tube for controlledly positioning said armature; securing means for selectively (a) fixedly retaining said coil at a preselected position longitudinally of said tube, and (b) permitting longitudinal movement of said coil past said opposite end of the solenoid tube for selective installation and removal of said coil relative to said control valve as desired; means for slidably supporting the armature in said said solenoid tube adjacent opposite ends of said armature, said solenoid coil comprising any one of a plurality of different coils providing correspondingly different positionings of said valve member when mounted concentrically surrounding said solenoid tube; and means for providing accurate positioning of said solenoid armature as a result of energization of said solenoid coil comprising means for slidably supporting said solenoid armature coaxially centered within said solenoid tube including means defining a low friction radially inner mirror finish surface on said solenoid tube and longitudinally spaced annular slides concentrically mounted to said solenoid armature having annular sliding engagement with said solenoid tube inner surface.