Apparatus for regulating the flow of fluid in medical apparatus

In combination with a container for intravenous fluid for delivering the fluid at a controlled rate to a patient, a flexible conduit extending from said container for delivery of said fluid, a valve in said conduit for adjusting the rate at which fluid is delivered, said valve comprising:

• a valve body having inlet and outlet openings and having a cylindrical passage therebetween defined by a cylindrical wall;
• a flow regulating member extending into the cylindrical passage and having an outer cylindrical surface closely engaging the wall of the cylindrical passage, the flow regulating member having a helical grooved portion on the outer cylindrical surface thereof to form a helical fluid passage through the valve body between said inlet and outlet openings, the pitch of the helical groove progressively varying from one end of the helical groove to the other;
• and
• actuating means for shifting the flow regulating member axially to vary the amount of the helically grooved portion that is disposed between the inlet and outlet openings to vary the length of the helical passage through which fluid must flow to adjust the flow of fluid from said container.