Patent ID: 8915969
Filing Date: 2014-12-23
Classification: A61F,F16F

Abstract:
1. A prosthesis comprising: a first artificial limb component; a second artificial limb component; a joint pivotally coupling said first and second artificial limb components to permit extension and flexion movements about the joint; and a hydraulic damper comprising a variable volume chamber for hydraulic fluid coupled between said first and second limb components; wherein the damper is operable to allow relative movement of said first and second limb components about the joint by passage of an incompressible hydraulic fluid through said variable volume chamber via an aperture of a valve, the valve being operable to determine a degree to which the hydraulic damper reactively resists a force to permit movement by a first pressure, which first pressure acts on a wall of the variable volume chamber; wherein the valve is disposed between the variable volume chamber and a hydraulic fluid sink on a second side of the valve; wherein a fluid flow rate of the incompressible hydraulic fluid through the valve is a conditioned function of a second pressure, which second pressure is less than the first pressure and is associated with fluid flow through the valve and is operable to maintain a positive flow rate through the valve as the first pressure increases, the conditioned function being characterized in that the second pressure as a function of the flow rate causes an increase in resistance of the valve to the flow caused by the first pressure, such that the fluid flow approaches but does not reach a maximum as the first pressure increases past a minimum pressure, whereby a fluid flow limit is established through the valve.