US4902414A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid chromatograph apparatus
Assignee: US Philips Corp
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Filing: 1989-04-18
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Granted: 1990-02-20
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Expires: 2009-04-18
Abstract
Abstract A liquid chromatograph apparatus comprises a plurality of solvent sources (140,105) feeding a pump (102) via a proportioning valve arrangement (100). The proportioning valve arrangement (100) has a plurality of inlets (108,109) and a single outlet (110) which is coupled to the inlet coupling (112) of the pump (102). The inlet coupling (112) is mounted directly on the pump head (103) and incorporates a filter (118). The pump outlet (137) is fed via a tube (138) to a chromatographic separating column. The solvent sources (104,105) are coupled to the proportioning valve inlets (108,109) via tubes (106,107) without the provision of separate filters. This gives more equal average flow rates and enables more accurate proportioning of the solvent mixture to be obtained.
Inventors
- 👤 Phillip A. James
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:33
CPC Classifications
G; G01; G01N; G01N30/00; G01N30/02; G01N30/26; G01N30/28; G01N30/34
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
149 words
A liquid chromatograph apparatus comprising: a plurality of solvent sources, pump means for pumping solvent, proportioning valve means for feeding solvent from said plurality of solvent sources to said pump means, said proportioning valve means having a separate inlet for each solvent from said plurality of solvent sources, said separate inlet for each solvent from said plurality of solvent sources providing a low impedance path by being free of filters, and said proportioning valve means having a single outlet, first means for coupling said single outlet of said proportioning valve means to an inlet of said pump means, said first means including a sintered filter disc, a chromatographic separating column, second means for coupling an outlet of said pump to an inlet of said chromatographic separating column, third means for providing a sample to said chromatographic separating column, and detecting means for detecting constituents eluding from chromatographic separating column.
Claim 2
Dependent Claim
149 words
A liquid chromatograph apparatus comprising: a plurality of solvent sources, pump means for pumping solvent, proportioning valve means for feeding solvent from said plurality of solvent sources to said pump means, said proportioning valve means having a separate inlet for each solvent from said plurality of solvent sources, said separate inlet for each solvent from said plurality of solvent sources providing a low impedance path by being free of filters, and said proportioning valve means having a single outlet, first means for coupling said single outlet of said proportioning valve means to an inlet of said pump means, said first means including a sintered filter disc, a chromatographic separating column, second means for coupling an outlet of said pump to an inlet of said chromatographic separating column, third means for providing a sample to said chromatographic separating column, and detecting means for detecting constituents eluding from chromatographic separating column.
Claim 3
Dependent Claim
33 words
A liquid chromatograph apparatus according to claim 1, wherein an inlet coupling is disposed at said inlet to said pump means, and wherein said sintered filter disc is provided in said inlet coupling.
Claim 4
Dependent Claim
29 words
A liquid chromatograph apparatus according to claim 3, wherein said inlet coupling includes a block of PTFE locating said filter at said sintered inlet disc of said pump means.
Claim 5
Dependent Claim
25 words
A liquid chromatograph apparatus according to claim 1 or claim 2, wherein said sintered filter disc includes one of sintered stainless steel or of PTFE.
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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) | 1993-02-19 | 1993-08-21 | 1994-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-19 | 1997-08-21 | 1998-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-19 | 2001-08-21 | 2002-02-20 | $7700.00 | Window Closed / Lapsed |