US4336038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter mat
Assignee: Carl Freudenberg KG
•
Filing: 1980-08-28
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Granted: 1982-06-22
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Expires: 2000-08-28
Abstract
Abstract A fibrous filter mat of which all or a part of the fibers are coated totally or at least in part with a mixture of at least two dye components which are insoluble in one another, one of said components being fat- and/or oil-soluble and of a color which contrasts with that of the fiber blend and/or of the other component, the other component being fat- and/or oil-insoluble. The mat is especially suited for kitchen exhaust hoods since entrapment of fats and oils causes a color change as the oil-soluble dye dissolves and spreads out.
Inventors
- 👤 Wolfram Schultheiss
- 👤 Harald Hoffmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:27
CPC Classifications
F; F24; F24C; F24C15/00; F24C15/20; F24C15/2035; B; B01; B01D; B01D46/00; B01D46/10; Y; Y10; Y10S; Y10S116/00; Y10S116/25; Y10S116/41; Y10S55/00; Y10S55/34; Y10S55/36
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
59 words
A fibrous filter mat in combination with a filter hood, the mat being printed on only its intake surface with a mixture of at least two dye components which are insoluble in one another, one of the dye components being oil soluble and another being oil-insoluble, the dye components contrasting in color from each other and from the fiber.
Claim 2
Dependent Claim
59 words
A fibrous filter mat in combination with a filter hood, the mat being printed on only its intake surface with a mixture of at least two dye components which are insoluble in one another, one of the dye components being oil soluble and another being oil-insoluble, the dye components contrasting in color from each other and from the fiber.
Claim 3
Dependent Claim
30 words
A filter mat according to claim 1, wherein the dye component mixture is printed in the form of dots and/or lines of a width of about 0.5 to 2 mm.
Claim 4
Dependent Claim
33 words
A filter mat according to claim 1, wherein the dye component mixture is printed in a striped or checkered pattern in which the parallel lines are spaced about 5 to 40 mm apart.
Claim 5
Dependent Claim
31 words
A filter mat according to claim 1, wherein the dye component mixture is printed in a striped or checkered pattern in which the parallel lines are spaced about 20 mm apart.
Claim 6
Dependent Claim
22 words
A filter mat according to claim 1, wherein the dye component mixture is printed in the form of written words or figures.
Claim 7
Dependent Claim
18 words
A filter mat according to claim 1, wherein the dye component mixture contains a size and/or bonding agent.
References Cited (Backward Citations)
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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) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |