Patent US3873449A successfully refreshed from Google Patents.
US3873449A
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US
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Filter skimming apparatus
Assignee: Baxter International Inc
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Filing: 1973-04-05
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Granted: 1975-03-25
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Expires: 1993-04-05
Abstract
Abstract Filter skimming apparatus comprising an elongated concave plunger arm adapted for telescopic insertion in a test tube. The plunger arm has an inverted cup-shaped piston head at the lower end for holding a filter element and having a rim for slidable sealing engagement of the inner walls of the test tube.
Inventors
- 👤 John J Connelly
- 👤 Stefano Alan A Di
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:50
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/483; G01N33/487; G01N33/49; G01N33/491; B; B01; B01L; B01L3/00; B01L3/50; B01L3/502; B01L3/5021; B01L2300/00; B01L2300/06; B01L2300/0681; B01L2400/00; B01L2400/04; B01L2400/0475; B01L2400/0478
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
125 words
Filter skimming apparatus comprising a plunger having an elongated arm, an inverted cup-shaped piston head, a filter cup disposed in said piston and containing a filter element, said piston head having an annular projection on its inner top and said filter cup having an annular projection on its inner bottom whereby a cavity is formed above said filter element and a second cavity is formed below said filter element, said piston head having an upwardly disposed, small bore tubelike extension and said filter cup having a downwardly extending, small bore probe offset from the center of the bottom of said filter cup, said plunger having a peripheral rim at the piston zone adapted for slidable sealing engagement of the inner walls of a test tube.
Claim 2
Dependent Claim
125 words
Filter skimming apparatus comprising a plunger having an elongated arm, an inverted cup-shaped piston head, a filter cup disposed in said piston and containing a filter element, said piston head having an annular projection on its inner top and said filter cup having an annular projection on its inner bottom whereby a cavity is formed above said filter element and a second cavity is formed below said filter element, said piston head having an upwardly disposed, small bore tubelike extension and said filter cup having a downwardly extending, small bore probe offset from the center of the bottom of said filter cup, said plunger having a peripheral rim at the piston zone adapted for slidable sealing engagement of the inner walls of a test tube.
Claim 3
Dependent Claim
68 words
The filter skimming device of claim 1 in which the tubelike extension is offset from the center of the top of said piston head toward the inner side of said elongated arm, the elongated arm is concave on its inner side and contains a small transverse opening at the top of said tubelike extension, and said peripheral rim is positioned on the lower extremity of said piston head.
References Cited (Backward Citations)
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US3512940A
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US3586064A
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US3693804A
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US3802843A
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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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |