Patent ID: 6113642
Filing Date: 2000-09-05
Classification: A61F,F16F

Abstract:
A device for producing a controlled variable resistance to apparatus including a first member moveable relative to a second member, said device comprising hydraulic actuator connecting said first member to said second member, said actuator including a housing enclosing a moveable resistance applying member separating a first chamber and a second chamber within said housing, hydraulic fluid passages connected to said chambers, hydraulic fluid within said chambers and said passages, a solenoid controlled valve connected to control the flow of hydraulic fluid through said passages, a magnet and a magnetically actuated electronic sensor arranged to sense changes in the hydraulic fluid pressure within at least one of said chambers, and a computer controlled electronic system responsive to said sensor for actuating said valve to control precisely the flow of said fluid through said valve and into and out of said first and second chambers.