Patent ID: 8449274

Claim:
A magnetic reciprocating pump, comprising: a tube having a cylindrical side wall closed by first and second ends to define a cylindrical internal chamber extending along a longitudinal axis, said tube ends respectively defining first and second ports communicating with said chamber; first and second elongate plungers reciprocatable within said chamber and including a side wall extending between inner and outer ends, each plunger carrying a magnet having longitudinally spaced poles, said first plunger movable between said first tube end and said second plunger, said second plunger being movable between said first plunger and said second tube end; said first plunger when moved from said first tube end defining therewith a first work space within said chamber, said plungers when moved apart defining therebetween a second work space within said chamber, said second plunger when moved from said second tube end defining therewith a third work space within said chamber; said first plunger defining a first flow path providing fluid communication between said first and second spaces; said second plunger defining a second flow path providing fluid communication between said second and third spaces; said first plunger having its outer end adapted to block said first port when moved to said first tube end, said second plunger having its outer end adapted to block said second port when moved to said second tube end, said first plunger having its inner end adapted to block said second flow path when said plungers are moved together; and, means for selectively applying a magnetic field to said plungers to effect longitudinal movement of said plungers within said tube and selectively position said plungers relative to the tube ends and to each other, whereby movement of said first plunger to said first tube end stops fluid flow through said first port, movement of said second plunger to said second tube end stops fluid flow through said second port, and movement of said plungers together stops fluid flow past said plungers.