Patent US3581902A successfully refreshed from Google Patents.
US3581902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter made from powdered metal
Assignee: 3M Co
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Filing: 1968-10-04
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Granted: 1971-06-01
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Expires: 1988-10-04
Abstract
Abstract A metallurgically integral filter comprising sintered laminae of shaped powdered metal, said laminae comprising an impervious structural member, a filter element, and a pervious support member sandwiched between said structural member and said filter element, with a drainage space between said structural member and said pervious support member. A series of such sintered filters can be stacked within a housing in spaced relation with the drainage areas of said filters communicating with a discharge pipe, to form a filter assembly useful in removing solid particles from liquids or gases.
Inventors
- 👤 James L Bidler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:03
CPC Classifications
B; B22; B22F; B22F7/00; B22F7/002; B22F7/004; B01; B01D; B01D29/00; B01D29/39; B01D29/41; B01D39/00; B01D39/14; B01D39/20; B01D39/2027; B01D39/2031; B01D39/2034
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
120 words
A metallurgically integral filter leaf of five jointly sintered laminae of powdered metal comprising, in combination: a substantially impervious core having a plurality of spaced-apart protuberances protruding form each side of said core; pervious support members disposed on each side of said core and contiguous with the protuberances protruding from said side, thereby forming a drainage space on each side of said core; and filter elements of less permeability than said support members and disposed on each of the outer sides of said support members and contiguous therewith; said core, support members, and filter elements being shaped in the form of discs with their peripheries metallurgically sealed together and having a common central opening which communicates with said drainage spaces.
Claim 2
Dependent Claim
16 words
A filter leaf according to claim 2, wherein said powdered metal comprises austenitic chromium-nickel stainless steel.
Claim 3
Dependent Claim
20 words
A filter leaf according to claim 3, whereiN said pervious support members comprise austenitic chromium-nickel stainless steel and ferrite stabilizer.
Claim 4
Dependent Claim
64 words
A filter assembly comprising, in combination: a housing having an inlet and an outlet, with a filtering chamber disposed within said housing and in communication with said inlet; a plurality of the filter leaves of claim 1 disposed within said chamber in spaced-apart relation and with the drainage areas of said filter leaves communicating with a common drainage conduit that communicates with said outlet.
Claim 5
Dependent Claim
94 words
A filter assembly comprising, in combination: a housing having an inlet at its upper end and an outlet at its lower end with a filter chamber disposed within said housing and in communication with said inlet; a plurality of the filter leaves of claim 2 disposed within said chamber, said filter leaves being mounted in spaced apart relation on a drainage shaft passing through the common central openings of said filter leaves, said shaft having drainage channels therein which communicate with said drainage spaces of said filter leaves and which communicates with said outlet.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |