Metering apparatus for a fluid infusion system with flow control station

Fluid metering apparatus for controlling the flow of fluid through the tubing of a fluid administration set, comprising:

• a housing;
• a rotor mounted on said housing for rotation about a fixed axis, said rotor including a plurality of pressure rollers disposed about the circumference thereof;
• a platen assembly slidably mounted to said housing and having a pressure plate having an open position displaced from the circumference of said rotor whereby said tubing can be inserted therebetween, and having a closed position adjacent said rotor circumference whereby a segment of said tubing is positioned in compressive engagement with said pressure rollers and fluid is caused to flow along the tubing with rotation of said rotor;
• flow restriction means including a plunger slidably mounted on said housing for occluding said tubing at a predetermined location downline of said tubing segment for increasing the pressure of said fluid in said tubing segment, said plunger having an open position removed from said tubing and a operating position compressively engaging said tubing;
• means carried on said housing for biasing said plunger to said operating position even if said platen assembly is accidently moved to said open position;
• and
• user-actuable latching means operable only when said platen assembly is in said open position for latching said plunger in said open position, said latching means automatically releasing said plunger to allow said plunger to move to said operating position upon actuation of said pressure plate to said closed position.