Patent US5423903A successfully refreshed from Google Patents.
US5423903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air filter
Assignee: Individual
•
Filing: 1994-01-31
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Granted: 1995-06-13
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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 21:08
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.
References Cited (Backward Citations)
US1843446A
Cited
US2055774A
Cited
US2195563A
Cited
US2400076A
Cited
US2430861A
Cited
US2589229A
Cited
US2579477A
Cited
US3217471A
Cited
US3319401A
Cited
US3430420A
Cited
US3630007A
Cited
US3577710A
Cited
US3727597A
Cited
US4418662A
Cited
US4514197A
Cited
US4784048A
Cited
US4917862A
Cited
US5129929A
Cited
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 |