Patent US 6,279,869

A proportional flow control valve having at least one pinch jaw that is movable between open and closed positions for engaging a fluid flow line passing through the valve. The valve includes a valve actuator generally formed from a shape memory alloy that engages and moves at least one movable pinch jaw. As an electrical current is applied to the shape memory alloy, the shape memory alloy exerts a moving force on the pinch jaw so as to move the pinch jaw into or out of engagement with a flow tube for controlling the opening and closing of the valve.