Patent ID: 7063513
Filing Date: 2006-06-20
Classification: F04B,G01N

Abstract:
1. A pump for feeding a liquid for chromatography, comprising: first and second chambers; first and second plungers forming first and second volumes respectively together with the first and second chambers and being capable of reciprocating in the first and second chambers respectively in such a manner that the first and second volumes are variable in accordance with respective movements of the first and second plungers; a communication path connecting fluidly the first and second volumes to each other; an inlet path communicating fluidly with the first volume, from which inlet path the liquid to be fed is capable of being supplied into the first volume; and an outlet path communicating fluidly with the second volume, by which outlet path the liquid to be fed is capable of being discharged from the second volume; wherein the first plunger is prevented from changing the first volume sufficiently for feeding the liquid between the first volume and the second volume when the second plunger decreases the second volume to discharge the fluid from the second volume to the outlet path for the chromatography; and wherein the first plunger is prevented from being moved during a time period which is greater than zero while the second plunger moves to decrease the second volume so that the fluid for the chromatography is discharged from the second volume.