Roller clamp for defining a flow lumen in tubing

A two piece roller clamp is disclosed for regulating the fluid flow rate through plastic tubing by defining the size of the tubing lumen. The clamp includes a U-shaped body with a base and two side walls and a longitudinally movable roller mounted in tracks formed in the side walls. The roller is biased against a roller bearing surface running along the length of the base. Adjacent to the roller bearing surface is a tube compression slot having a lower wall uniformly spaced below the roller. A channel of varying cross-section is provided in the lower wall of the tube compression slot. The roller exerts a uniform, but minimal force on the tubing compressing it against the lower wall of the slot permitting the formation of a lumen defined by the contours of the channel. The slot is dimensioned vertically to provide for the minimal compression force by the roller and is dimensioned horizontally to confine the entire compressed cross-section of tubing without excess space thereby conforming the tubing to the contours of the channel to regulate the lumen size. A uniform compression force is maintained during longitudinal movement of the roller by the roller bearing surfaces which prevent perpendicular movement of the roller towards the slot.