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US 7,063,513 B2Granted
Liquid chromatograph pump with dual cylinders and dual plungers
AssigneeHitachi High-Technologies Corporation
InventorsKenji Hiraku, Kunihiko Takao, Hironori Kaji, Masahito Ito
Life of this patent
Estimating the term…
Abstract
In a pump for feeding a liquid for chromatography, first and second plungers form first and second volumes respectively together with first and second chambers, the first plunger is prevented from changing the first volume sufficiently for feeding the liquid between the first and second volumes when the second plunger decreases the second volume to discharge the fluid from the second volume to an outlet path of the pump for the chromatography.
Claims21
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.
6 more elements
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;
- 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;
- and
- wherein a movement velocity in absolute value of the second plunger for increasing the second volume is larger than a movement velocity in absolute value of the second plunger for decreasing the second volume to discharge the fluid from the second volume to the outlet path for the chromatography.
7 more elements
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;
- wherein the first plunger is prevented from being moved during a time peroid 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;
- wherein the communication path connects fluidly the first and second volumes to each other in series so that the liquid to be fed for the chromatography is capable of being fed from the first volume through the communication path to the second volume, the communication path includes a check valve for allowing the liquid to flow from the first volume into the second volume when a pressure in the first volume is higher than a pressure in the second volume and preventing the liquid from flowing from the second volume into the first volume when the pressure in the first volume is not higher than the pressure in the second volume;
- wherein the check valve is capable of allowing the liquid to flow from the first volume into the second volume when the pressure in the first volume is higher than the pressure in the second volume and a difference in absolute value between the pressure in the first volume and the pressure in the second volume is more than a predetermined value more than zero, and of preventing the liquid from flowing from the first volume into the second volume when the pressure in the first volume is not higher than a total amount of the pressure in the second volume and the predetermined value;
- wherein the first plunger is prevented from decreasing the first volume sufficiently for increasing the pressure of the liquid in the first volume to more than the total amount of the pressure in the second volume and the predetermined value 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 when the second plunger decreases the second volume to discharge the fluid from the second volume to the outlet path for the chromatography, the first plunger is capable of decreasing the first volume to increase the pressure of the liquid in the first volume to more than a pressure in the inlet path and is prevented from decreasing the first volume sufficiently for increasing the pressure of the liquid in the first volume to more than the total amount of the pressure in the second volume and the predetermined value.
10 more elements
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;
- 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;
- wherein the communication path connects fluidly the first and second volumes to each other in series so that the liquid to be fed for the chromatography is capable of being fed from the first volume through the communication path to the second volume, the communication path includes a check valve for allowing the liquid to flow from the first volume into the second volume when a pressure in the first volume is higher than a pressure in the second volume and preventing the liquid from flowing from the second volume into the first volume when the pressure in the first volume is not higher than the pressure in the second volume;
- and
- wherein when the second plunger decreases the second volume to discharge the fluid from the second volume to the outlet path for the chromatography, the first plunger is capable of decreasing the first volume to increase the pressure of the liquid in the first volume to more than a pressure in the inlet path and is prevented from decreasing the first volume sufficiently for increasing the pressure of the liquid in the first volume to more than the pressure in the second chamber.
8 more elements
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 outlet path includes a drain valve openable to discharge a gas out of the outlet path through the drain valve to fill the outlet path with the liquid when the first plunger decreases the first volume, and closable to discharge the fluid from the second volume out of the pump through the outlet path for the chromatography when the second plunger decreases the second volume.
6 more elements
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;
- wherein the first plunger is prevented from being moved while the second plunger moves to decrease the second volume so that the fluid for the chromatography is discharged from the second volume;
- and
- wherein the first plunger moves to decrease the first volume in response to the second plunger reaching a front end of a moving stroke of the second plunger.
7 more elements
Dependencies are inferred from the claim text.