US3710562A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual element air filter
Assignee: SANDMASTER CO
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Filing: 1972-03-27
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Granted: 1973-01-16
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Expires: 1992-03-27
Abstract
Abstract A dual element, self cleaning air filter for cleaning excessively dirty air. A base contains a central air outlet nozzle and retains a bracket which supports a cover in spaced relation from the base. The cover includes a depending flange which extends in an adjacently spaced relation with respect to the margin of the base. An outer, pleated paper-type filter and an inner, resilient foam filter in mutually spaced concentric relation extend between and are positionally retained by the base and the cover. An air inlet passage is defined between the depending flange and the outer filter.
Inventors
- 👤 M Mckenzie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:25
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/52; B01D46/521; B01D46/0052; B01D46/0053; B01D46/24; B01D46/2403; B01D46/2411; B01D46/56; B01D46/62; B01D46/64; F; F02; F02M; F02M35/00; F02M35/02; F02M35/024; B01D2267/00; B01D2267/40; B01D2279/00; B01D2279/60; Y; Y10; Y10S; Y10S55/00; Y10S55/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
218 words
A dual filter for a contaminated air stream, the combination comprising: a base member including air outlet passage means disposed centrally thereof; a first generally cylindrical open ended filter upon said base member concentric with said outlet passage means, said first filter fabricated from foamed material adapted for oil-wetting to permit air passage therethrough while removing small dirt particles from the airstream, screen means positioned against and supporting said first filter downstream thereof, filter-locating means upon and acting at said base member to maintain said concentricity, a second generally cylindrical filter, including pleated paperlike filter element, positioned upon said base member concentrically surrounding said first filter in spaced relation thereto for preventing the passage of a major portion of small foreign particles therethrough, and second filter, including coarse metallic screen means enclosing said filter element, and adapted to permit the passage of air therethrough; cover attachment means fixed to and extending from said base member; a cover member retained by said cover attachment means, spaced from said base member, removably engaging with each of said filters and confining each of said filters between said cover member and said base member, and including a depending skirt member substantially encompassing the length as said filters and cooperating with said outer filter to define an air inlet to said dual filter.
Claim 2
Dependent Claim
218 words
A dual filter for a contaminated air stream, the combination comprising: a base member including air outlet passage means disposed centrally thereof; a first generally cylindrical open ended filter upon said base member concentric with said outlet passage means, said first filter fabricated from foamed material adapted for oil-wetting to permit air passage therethrough while removing small dirt particles from the airstream, screen means positioned against and supporting said first filter downstream thereof, filter-locating means upon and acting at said base member to maintain said concentricity, a second generally cylindrical filter, including pleated paperlike filter element, positioned upon said base member concentrically surrounding said first filter in spaced relation thereto for preventing the passage of a major portion of small foreign particles therethrough, and second filter, including coarse metallic screen means enclosing said filter element, and adapted to permit the passage of air therethrough; cover attachment means fixed to and extending from said base member; a cover member retained by said cover attachment means, spaced from said base member, removably engaging with each of said filters and confining each of said filters between said cover member and said base member, and including a depending skirt member substantially encompassing the length as said filters and cooperating with said outer filter to define an air inlet to said dual filter.
Claim 3
Dependent Claim
21 words
The filter of claim 1 wherein said filter is of foamed plastic and said second filter is of pleated filter paper.
Claim 4
Dependent Claim
21 words
The filter of claim 1 wherein a fine textured screen is positioned circumferentially within and in contact with said second filter.
Claim 5
Dependent Claim
19 words
The filter of claim 1 wherein said air outlet passage means is configured as an inwardly tapered nozzle-like structure.
Claim 6
Dependent Claim
98 words
The filter of claim 4 wherein a bracket attached to said base member straddles said air outlet passage means, extends toward said cover member, and is of a width at its attachment position to said base member substantially matching the internal diameter of said first filter means, bolt means affixed to said bracket and adapted for removably attaching and retaining the position of said cover member, the relative lengths of said filter members being such as to facilitate a contact and an axial compression of said first filter means before contacting and stopping against said second filter means.
Claim 7
Dependent Claim
11 words
The filter of claim 1 wherein said filter is oil wetted.
References Cited (Backward Citations)
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Cited
US2848065A
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US3012631A
Cited
US2966234A
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US3488928A
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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) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |