US4231876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reusable coffee filter
Assignee: Maxs AG
•
Filing: 1979-02-15
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Granted: 1980-11-04
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Expires: 1999-02-15
Abstract
Abstract A coffee filter which may be used repeatedly is described. It comprises a funnel-shaped housing having an outlet port at the lower end. A filter of similar shape is fitted into the housing and is so dimensioned as to provide a clearance of between 0.2 to 1.5 mm. The filtering element is so dimensioned that the upper rim thereof forms a seal with the inner wall of the housing. The outlet port of the housing has a restriction in order to assume a continuous flow of the filtrate between the funnel-shaped housing and the filtering element.
Inventors
- 👤 Anton Zimmermann
- 👤 Albert Greutert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:18
CPC Classifications
A; A47; A47J; A47J31/00; A47J31/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
244 words
A reusable coffee filter assembly for use in providing a filtrate of liquid such as coffee, said assembly comprising: a cone-shaped funnel and a reusable filtering element positionable within said funnel; coacting spacing means to critically space an inner surface of said funnel and an outer surface of said filtering element at a distance of between from 0.2 mm and 1.5 mm from each other when said filtering element is positioned within said funnel, said spacing means including an inwardly extending peripheral rib at an upper inner portion of said funnel, a plurality of spaced inwardly extending protrusions on a lower portion of said inner surface of said funnel adjacent a lower outlet port of said funnel, and a peripheral groove at an upper portion of said filtering element, said groove engaging said rib, and a minimal outer surface portion of said filtering element contacting said spaced protrusions to maintain said critical spacing between said inner surface of said funnel and said outer surface of said filtering element to provide a substantial filtering area in which a continuous layer of the filtrate is formed on said inner surface of said funnel and passes through said outlet port as a continuous column of liquid; and a throttling means in said outlet port, said throttling means being so dimensioned and spaced in said outlet port to control the flow of the filtrate to maintain said continuous layer of filtrate whereby a rapid filtering speed is attained.
Claim 2
Dependent Claim
244 words
A reusable coffee filter assembly for use in providing a filtrate of liquid such as coffee, said assembly comprising: a cone-shaped funnel and a reusable filtering element positionable within said funnel; coacting spacing means to critically space an inner surface of said funnel and an outer surface of said filtering element at a distance of between from 0.2 mm and 1.5 mm from each other when said filtering element is positioned within said funnel, said spacing means including an inwardly extending peripheral rib at an upper inner portion of said funnel, a plurality of spaced inwardly extending protrusions on a lower portion of said inner surface of said funnel adjacent a lower outlet port of said funnel, and a peripheral groove at an upper portion of said filtering element, said groove engaging said rib, and a minimal outer surface portion of said filtering element contacting said spaced protrusions to maintain said critical spacing between said inner surface of said funnel and said outer surface of said filtering element to provide a substantial filtering area in which a continuous layer of the filtrate is formed on said inner surface of said funnel and passes through said outlet port as a continuous column of liquid; and a throttling means in said outlet port, said throttling means being so dimensioned and spaced in said outlet port to control the flow of the filtrate to maintain said continuous layer of filtrate whereby a rapid filtering speed is attained.
Claim 3
Dependent Claim
15 words
The filter assembly of claim 1 wherein said filtering element is a perforated metal foil.
Claim 4
Dependent Claim
15 words
The filter assembly of claim 1 wherein said filtering element is a perforated rigid plastic.
References Cited (Backward Citations)
DE294311C
Cited
US2166980A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-04 | 1984-05-05 | 1984-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-04 | 1988-05-05 | 1988-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-04 | 1992-05-05 | 1992-11-04 | $7700.00 | Window Closed / Lapsed |