Flow control device

A tubing clamp for regulating flow of fluid through a length of flexible tubing comprising:

• a clamp body defining a surface for supporting a length of flexible tubing having a longitudinal axis;
• opposing walls extending from said support surface and presenting a passage for said tubing;
• a platen mounted between said walls for contacting said tubing;
• guide surfaces arranged in said walls;
• a first rotatable member positioned to be guided by said guide surfaces:
• said platen constructed and arranged to be movably positioned between said first rotatable member and said tubing;
• said platen presenting a compression surface against said tubing substantially along and over the path of travel of said first rotatable member, and cooperating with said first rotatable member to exert an incremental compressive force on said tubing and by means of said platen to distribute the compressive force of said first rotatable member over a wide area of said tubing including a substantial distance along its longitudinal axis;
• and
• a second rotatable member operatively positioned within said clamp body and arranged to cooperate with said first rotatable member and said platen to exert an incremental compressive force upon said tubing whereby said first rotatable member and said second rotatable member provide separate control means for coarse and fine regulation of said flow of liquid through said flexible tubing;
• said first rotatable member being a roller having pins extending therefrom and said guide surfaces comprise a plurality of grooves with said pins positioned in said grooves and said grooves having an axis positioned to intersect the axis of said support surface;
• said roller being adapted to rotate within said grooves and thereby to move longitudinally along said grooves so as to compress said platen against said tubing and thereby constrict same;
• and
• said second rotatable member comprising a roller having pins extending therefrom with said pins positioned in said opposing walls, whereby movement of said first rotatable member along said guide surface is effective to contact said first rotatable member initially against said platen so as to pivot said platen against said tubing thereby compressing said tubing and consequently constricting said flow of liquid through said tubing;
• movement of said second rotatable member against said platen being effective to further compress said platen against said tubing thereby further compressing said tubing so as to incrementally increase or decrease said flow of said liquid in minute quantities.