Fluid control means for vehicle suspension system

In a vehicle suspension system of the type including an extensible and retractable passive hydraulic damper assembly interconnecting relatively moveable vehicle components and adapted to passively attenuate motion of at least one of said components, and further including a fluid accumulator connected to said damper assembly and adapted during operation thereof to receive hydraulic fluid from and to passively supply hydraulic fluid to said assembly, the improvement comprising:

• signal responsive control valve means for controlling the flow of fluid from said damper assembly to said accumulator;
• said control valve means including an elongate shaft-like magnetic member having a central blind passageway extending along part of the length and opening from one end thereof for receiving fluid passing from said damper assembly to said accumulator;
• said shaft-like member having a set of slot-like fluid outlet openings extending generally radially outwardly from said fluid passageway through the outer circumference of said member, said openings being spaced substantially equally from one another about the circumference of said member with the major axes thereof lying within a common plane perpendicular to the central axis of said member;
• an annular magnetic member encircling said first-mentioned magnetic member at a location spaced longitudinally from the section thereof having said passageway therewithin, said magnetic members being of opposite magnetic polarities and defining therebetween a narrow annular gap traversed by magnetic flux;
• a tubular bobbin formed of lightweight nonmagnetic material, said bobbin encircling and being freely slidable longitudinally of said first magnetic member between first and second positions spaced along the length of said first member by a distance only slightly greater than the width of said slot-like outlet openings therein, said bobbin in said first position thereof permitting maximum flow of fluid from said outlet openings of said member and in said second position thereof retarding flow of fluid from said outlet openings;
• coil means carried by and encircling an end portion of said bobbin closely received within said annular gap between said magnetic members in both of said positions of said bobbin, said bobbin being rapidly moved to and maintained in said first position thereof by the application to said coil of a first electrical command signal and being rapidly moved to and maintained in said second position thereof upon the application of said coil means of an opposite sign second command signal;
• and electronic control means for monitoring movement characteristics of said vehicle components and for applying command voltage signals to said coil means continuously during operation of said system, said control means applying said first command signal to said coil means at those times when said damper would tend to amplify motion of said one of said vehicle components and at other times applying said second command signal to said coil means.