US5393434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid chromatography method
Assignee: Zymark Corp
•
Filing: 1993-11-22
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Granted: 1995-02-28
•
Expires: 2013-11-22
Abstract
Abstract A liquid chromatography system including a liquid pump having a pumping chamber, an inlet port, an outlet port, and a purge port, all communicating with the pumping chamber; a separation column; an outlet valve connected between the outlet port and the separation column and adapted to control liquid flow therebetween; a source of mobile phase; an inlet valve connected between the inlet port and the source and adapted to control liquid flow therebetween; and a purge valve connected to the purge port.
Inventors
- 👤 Burleigh M. Hutchins
- 👤 Raymond R. Dunlap
- 👤 Timothy J. Conklin
- 👤 Bruce A. Swanson
- 👤 John Petracca
- 👤 Louis Abrahams
- 👤 Ronald A. Kimball
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:42
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/26; G01N30/28; G01N30/32; F; F04; F04B; F04B49/00; F04B49/06; F04B49/065; F04B53/00; F04B53/06; F04B53/10; F04B53/102; F04B53/1032; F04B53/14; F04B53/144; F04B53/147; F04B7/00; F04B7/0076; F04B9/00; F04B9/02; F04B2205/00; F04B2205/03; G01N2030/326; G01N2030/328; Y; Y10; Y10T; Y10T403/00; Y10T403/32; Y10T403/32114; Y10T403/32196; Y10T403/32606; Y10T403/32631; Y10T403/36; Y10T403/51; Y10T74/00; Y10T74/18; Y10T74/18568; Y10T74/18576; Y10T74/19; Y10T74/19642; Y10T74/19698; Y10T74/19702
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
108 words
A method of operating liquid chromatography apparatus including a liquid pump having a pumping chamber, an inlet valve for receiving liquid, an outlet valve for discharging liquid to a separation column, a piston for drawing liquid through said inlet valve during a backstroke and discharging liquid through said outlet valve during a forward stroke, and a purge valve for purging the pumping chamber; the method comprising the steps of: monitoring the pumping performance of said liquid pump to detect the presence of air in said pumping chamber; opening said purge valve; and producing a forward stroke of said piston to discharge the detected air through said purge valve.
Claim 2
Independent Claim
108 words
A method of operating liquid chromatography apparatus including a liquid pump having a pumping chamber, an inlet valve for receiving liquid, an outlet valve for discharging liquid to a separation column, a piston for drawing liquid through said inlet valve during a backstroke and discharging liquid through said outlet valve during a forward stroke, and a purge valve for purging the pumping chamber; the method comprising the steps of: monitoring the pumping performance of said liquid pump to detect the presence of air in said pumping chamber; opening said purge valve; and producing a forward stroke of said piston to discharge the detected air through said purge valve.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein said monitoring step comprises monitoring the liquid pressure produced by said pump.
Claim 4
Dependent Claim
18 words
A method according to claim 2 wherein said monitoring step comprises monitoring the pressure in said pumping chamber.
Claim 5
Dependent Claim
27 words
A method according to claim 3 wherein said purge valve comprises an actuating solenoid and said opening step comprises actuating said solenoid to open said purge valve.
Claim 6
Dependent Claim
44 words
A method according to claim 3 including the step of stopping said piston in a mid-portion of said forward stroke, and wherein said monitoring step comprises monitoring the pressure in said pumping chamber with said piston stopped in said mid-portion of said forward stroke.
Claim 7
Independent Claim
193 words
A method of operating liquid chromatography apparatus including a first liquid pump having a first pumping chamber, a first inlet valve for passing liquid into said first pumping chamber, a first outlet valve for discharging liquid from said first pumping chamber, a first piston for drawing liquid through said first inlet valve during a backstroke and discharging liquid through said first outlet valve during a forward stroke, and a first pressure sensor for sensing the pressure in the first pumping chamber; a second liquid pump having a second pumping chamber, a second inlet valve for passing liquid into said second pumping chamber, a second outlet valve for discharging liquid from said second pumping chamber, a second piston for drawing liquid through said second inlet valve during a backstroke and discharging liquid through said second outlet valve during a forward stroke; the method comprising the steps of: stopping said first piston in a mid-portion of said forward stroke; monitoring the pressure in said first pumping chamber with said first piston stopped in said mid-portion of said forward stroke; and controlling the operation of said first and second pumps in response to said monitoring step.
Claim 8
Independent Claim
193 words
A method of operating liquid chromatography apparatus including a first liquid pump having a first pumping chamber, a first inlet valve for passing liquid into said first pumping chamber, a first outlet valve for discharging liquid from said first pumping chamber, a first piston for drawing liquid through said first inlet valve during a backstroke and discharging liquid through said first outlet valve during a forward stroke, and a first pressure sensor for sensing the pressure in the first pumping chamber; a second liquid pump having a second pumping chamber, a second inlet valve for passing liquid into said second pumping chamber, a second outlet valve for discharging liquid from said second pumping chamber, a second piston for drawing liquid through said second inlet valve during a backstroke and discharging liquid through said second outlet valve during a forward stroke; the method comprising the steps of: stopping said first piston in a mid-portion of said forward stroke; monitoring the pressure in said first pumping chamber with said first piston stopped in said mid-portion of said forward stroke; and controlling the operation of said first and second pumps in response to said monitoring step.
Claim 9
Dependent Claim
32 words
A method according to claim 6 wherein said controlling step comprises adjusting the output of said second pump to compensate for a deficiency of said first pump indicated by said monitoring step.
Claim 10
Dependent Claim
27 words
A method according to claim 7 wherein said controlling step comprises increasing the output of said second pump to compensate for said deficiency of said first pump.
Claim 11
Dependent Claim
37 words
A method according to claim 6 wherein said controlling step comprises the steps of deactivating said first pump and activating said second pump in response to a failure of said first pump indicated by said monitoring step.
Claim 12
Dependent Claim
46 words
A method according to claim 6 wherein said first inlet valve is connected to a first source of mobile phase and said second inlet valve is connected to a second source of mobile phase, and said controlling step comprises adjusting the performance of said second pump.
Claim 13
Dependent Claim
27 words
A method according to claim 10 wherein said controlling step comprises reducing the output of said second pump to compensate for said deficiency of said first pump.
Claim 14
Independent Claim
131 words
A method of operating liquid chromatography apparatus including a liquid pump having a pumping chamber, an inlet valve for receiving liquid, an outlet valve for discharging liquid to a separation column, a piston for drawing liquid through said inlet valve during a backstroke and discharging liquid through said outlet valve during a forward stroke, and a pressure sensor for sensing the pressure in the pumping chamber; the method comprising the steps of: monitoring with said pressure sensor the pressure in said pumping chamber during said forward stroke of said piston to detect the presence of air in said pumping chamber; determining the deficiency in liquid flow produced by said pump because of said detected air in said pumping chamber; and adjusting the operation of said pump to compensate for said deficiency.
Claim 15
Independent Claim
131 words
A method of operating liquid chromatography apparatus including a liquid pump having a pumping chamber, an inlet valve for receiving liquid, an outlet valve for discharging liquid to a separation column, a piston for drawing liquid through said inlet valve during a backstroke and discharging liquid through said outlet valve during a forward stroke, and a pressure sensor for sensing the pressure in the pumping chamber; the method comprising the steps of: monitoring with said pressure sensor the pressure in said pumping chamber during said forward stroke of said piston to detect the presence of air in said pumping chamber; determining the deficiency in liquid flow produced by said pump because of said detected air in said pumping chamber; and adjusting the operation of said pump to compensate for said deficiency.
Claim 16
Dependent Claim
21 words
A method according to claim 12 wherein said adjusting step comprises adjusting the length of said forward stroke of said piston.
Claim 17
Dependent Claim
21 words
A method according to claim 12 wherein said adjusting step comprises adjusting the speed of said forward stroke of said piston.
Claim 18
Dependent Claim
20 words
A method according to claim 12 wherein said adjusting step comprises adjusting the speed of said backstroke of said piston.
Claim 19
Dependent Claim
19 words
A method according to claim 12 wherein said monitoring is performed during an early portion of said forward stroke.
Claim 20
Independent Claim
274 words
A method of operating liquid chromatography apparatus including a first liquid pump having a first pumping chamber, a first inlet valve for passing liquid into said first pumping chamber, a first outlet valve for discharging liquid from said first pumping chamber to a separation system, a first piston for drawing liquid through said first inlet valve during a backstroke of said first piston and discharging liquid through said first outlet valve during a forward stroke thereof, and a first pressure sensor for sensing the pressure in the first pumping chamber and a first motor coupled to said first piston; and a second liquid pump having a second pumping chamber, a second inlet valve for passing liquid into said second pumping chamber, a second outlet valve for discharging liquid from said second pumping chamber to said separation system, a second piston for drawing liquid through said second inlet valve during a backstroke of the second piston and discharging liquid through said second outlet valve during a forward stroke thereof; a second motor coupled to said second piston, and a second pressure sensor for sensing the pressure in said second pumping chamber; the method comprising the steps of: monitoring with said pressure sensor the pressure in said first pumping chamber to detect an end of said forward stroke by said first piston; initiating said forward stroke of said second piston in response to said monitoring step; sensing with said second pressure sensor the pressure in said second pumping chamber to detect an end of said forward stroke by said second piston; and initiating said forward stroke of said first piston in response to said sensing step.
Claim 21
Independent Claim
274 words
A method of operating liquid chromatography apparatus including a first liquid pump having a first pumping chamber, a first inlet valve for passing liquid into said first pumping chamber, a first outlet valve for discharging liquid from said first pumping chamber to a separation system, a first piston for drawing liquid through said first inlet valve during a backstroke of said first piston and discharging liquid through said first outlet valve during a forward stroke thereof, and a first pressure sensor for sensing the pressure in the first pumping chamber and a first motor coupled to said first piston; and a second liquid pump having a second pumping chamber, a second inlet valve for passing liquid into said second pumping chamber, a second outlet valve for discharging liquid from said second pumping chamber to said separation system, a second piston for drawing liquid through said second inlet valve during a backstroke of the second piston and discharging liquid through said second outlet valve during a forward stroke thereof; a second motor coupled to said second piston, and a second pressure sensor for sensing the pressure in said second pumping chamber; the method comprising the steps of: monitoring with said pressure sensor the pressure in said first pumping chamber to detect an end of said forward stroke by said first piston; initiating said forward stroke of said second piston in response to said monitoring step; sensing with said second pressure sensor the pressure in said second pumping chamber to detect an end of said forward stroke by said second piston; and initiating said forward stroke of said first piston in response to said sensing step.
Claim 22
Dependent Claim
76 words
A method according to claim 17 including the steps of determining system pressure in said separation system, initiating said forward stroke of said first piston to provide said system pressure in said first pumping chamber at the end of said forward stroke by said second piston, and initiating said forward stroke of said second piston to provide said system pressure in said second pumping chamber at the end of said forward stroke of said first piston.
Claim 23
Dependent Claim
50 words
A method according to claim 17 wherein said initiating steps comprise initiating said forward stroke of said second piston at the end of said forward stroke of said first piston, and initiating said forward stroke of said first piston at the end of said forward stroke of said second piston.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-02-27 | 1998-08-29 | 1999-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-27 | 2002-08-29 | 2003-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-27 | 2006-08-29 | 2007-02-28 | $7700.00 | Window Closed / Lapsed |