US5423903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air filter
Assignee: Individual
•
Filing: 1994-01-31
•
Granted: 1995-06-13
•
Expires: 2014-01-31
Abstract
Abstract An air filter for use in filtering air entering an operator's cab of a human-operated machine. A fine mesh screen and air permeable fibrous cover are added to the air outlet side of a conventional air filter. An accordion-shaped filter element of the conventional filter is located upstream of the fine mesh screen. Granular filter material such as activated charcoal fills the space between the accordion-shaped filter element and the fibrous cover. An air-impermeable strip may be added at the top portion of the fine-mesh screen across the full width of the air filter to prevent air from flowing through a void in the granular filter material which may develop over time due to settling.
Inventors
- 👤 Michael Schmitz
- 👤 Eugene Ahrenholtz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:06
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/10; B01D46/30; B01D46/52; B01D46/521; B01D46/56; B01D46/62; B01D53/00; B01D53/02; B01D53/04; B01D53/0407; B01D2253/00; B01D2253/10; B01D2253/102; B01D2257/00; B01D2257/70; B01D2259/00; B01D2259/45; B01D2259/4566; B01D2267/00; B01D2267/40
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
68 words
A self-cleaning air filter, comprising: (a) a main frame having an air inlet and an air outlet; (b) an accordion-shaped, air permeable fibrous filter located within said main frame; (c) granular filter material substantially filling the folds of said accordion filter; (d) a structural member contiguous with said accordion filter and contiguous with said granular filter material; and (e) an air-permeable fibrous filter contiguous with said structural member.
Claim 2
Dependent Claim
68 words
A self-cleaning air filter, comprising: (a) a main frame having an air inlet and an air outlet; (b) an accordion-shaped, air permeable fibrous filter located within said main frame; (c) granular filter material substantially filling the folds of said accordion filter; (d) a structural member contiguous with said accordion filter and contiguous with said granular filter material; and (e) an air-permeable fibrous filter contiguous with said structural member.
Claim 3
Dependent Claim
28 words
The air filter as defined in claim 1, wherein an air-impermeable strip is interposed between a portion of said accordion filter and a portion of said structural member.
Claim 4
Dependent Claim
29 words
An air filter as defined in claim 1, wherein an air-impermeable strip is interposed between a portion of said accordion filter and a portion of said air-permeable fibrous filter.
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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) | 1998-06-12 | 1998-12-12 | 1999-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-12 | 2002-12-12 | 2003-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-12 | 2006-12-12 | 2007-06-13 | $7700.00 | Window Closed / Lapsed |