Patent US4690754A successfully refreshed from Google Patents.
US4690754A
Expired / Lapsed
US
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Filter device for a minute volume of liquid
Assignee: TOYO SODA MANUFACTURING Co Ltd 4560 OAZA TONDA SHINNANYO-SHI YAMAGUCHI-KEN JAPAN
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Filing: 1986-03-10
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Granted: 1987-09-01
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Expires: 2006-03-10
Abstract
Abstract A filter device for a minute volume of liquid, usable under a centrifugal force or under pressure, comprising a cylindrical member and a hollow thread filter having an open lower end and housed in said cylindrical member to form an annular space for containing a sample liquid around the filter, with the lower part of the hollow thread filter liquid-tightly bonded to the inside wall of the lower part of the cylindrical member and with the upper end of the hollow thread filter sealed.
Inventors
- 👤 Kenji Koyama
- 👤 Shotaro Ohno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 04:06
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/16; B01D61/00; B01D61/14; B01D61/18; B01D63/02; B01D63/024; B01D2313/00; B01D2313/20; B01D2313/206; B01D2313/2062
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
110 words
A filter device for a minute volume of liquid in combination with means for applying pressure or centrifugal force, said filter device comprising a cylindrical member and a single hollow fiber filter having an open lower end and housed in said cylindrical member to form an annular space for containing a sample liquid around the filter, with the lower part of the hollow fiber filter liquid-tightly bonded to the inside wall of the lower part of the cylindrical member and with the upper end of the hollow fiber filter sealed, said hollow fiber filter being a microfilter having micro-scale pores observable only with an electron microscope or an ultrafiltration membrane.
Claim 2
Dependent Claim
110 words
A filter device for a minute volume of liquid in combination with means for applying pressure or centrifugal force, said filter device comprising a cylindrical member and a single hollow fiber filter having an open lower end and housed in said cylindrical member to form an annular space for containing a sample liquid around the filter, with the lower part of the hollow fiber filter liquid-tightly bonded to the inside wall of the lower part of the cylindrical member and with the upper end of the hollow fiber filter sealed, said hollow fiber filter being a microfilter having micro-scale pores observable only with an electron microscope or an ultrafiltration membrane.
Claim 3
Dependent Claim
18 words
A filter device according to claim 1, wherein the hollow fiber filter is composed of an ultrafiltration membrane.
Claim 4
Dependent Claim
34 words
A filter device according to claim 1, in which the cylindrical member is tapered to be narrowed at least at the lower portion so as to be in the shape of a truncated cone.
Claim 5
Dependent Claim
28 words
A filter device according to claim 1, in which the hollow fiber filter is made of transparent or semi-transparent material non-reactive to a liquid sample to be filtered.
Claim 6
Dependent Claim
29 words
A filter device according to claim 1, in which the cylindrical member has an inner diameter 1.5 to 3 times larger than the largest outer diameter of the filter.
Claim 7
Dependent Claim
23 words
A filter device according to claim 1, in which the filter has an inner diameter of 60 to 80% of its outer diameter.
References Cited (Backward Citations)
US4267053A
Cited
US4242203A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-31 | 1991-03-02 | 1991-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-31 | 1995-03-02 | 1995-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-31 | 1999-03-02 | 1999-09-01 | $7700.00 | Window Closed / Lapsed |