Patent US3630362A successfully refreshed from Google Patents.
US3630362A
Expired / Lapsed
US
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Self-cleaning filter systems
Assignee: Plessey Overseas Ltd
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Filing: 1969-05-08
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Granted: 1971-12-28
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Expires: 1989-05-08
Abstract
Abstract To ensure, by purely fluidic means, the alternate use of two filter units, one being in the main fluid path while the other is being reconditioned by back flushing with filtered liquid, two parallel branch paths are interposed between the main-flow inlet of a bistable fluidic device and a service outlet each branch including a filter and having a reverse-flow switch interposed between the bistable, which has two control jets, and the filter so as to conduct flow from the bistable to the filter but divert flow from the filter into a spill path, the switching of the bistable device being controlled by connecting the inlet of each control jet in parallel to the inlet of the appropriate filter and, via a restrictor to the fluid inlet of the system.
Inventors
- 👤 Robert B Matthews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:17
CPC Classifications
F; F15; F15C; F15C1/00; F15C1/008; B; B01; B01D; B01D35/00; B01D35/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
261 words
A self-cleaning filter system for the flow of fluid from a source of impure fluid to a consumer of filtered fluid at a pressure lower than that at the source, which comprises a pure fluidic bistable switch having, two opposite wall surfaces confining between them a passage forming a main-flow inlet for connection to such source at one end, and branched at its other end to form two main flow outlets connected to said main-flow inlet in parallel to each other as to enable the Coanda effect of said wall surfaces to alternatively establish a first stable flow condition in which substantially all said main flow will pass through one, and a second stable flow condition in which substantially all said main flow will pass through the other main-flow outlet, and two control inlets having jet-forming means for the respective production of fluid jets acting upon the flow from the main-flow inlet to respectively change the main flow from said first stable flow condition to said second stable flow condition and vice versa, two filter elements respectively connected to said two main-flow outlets, and two pure-fluidic reverse-flow switches each having a through passage and a spill outlet, said through passages of the two reverse-flow switches being respectively interposed in the connection between each main-flow outlet of the bistable device and the associated filter, and each reverse-flow switch being so arranged as to permit flow from the bistable device through said through passage to the filter but to divert to said spill outlet flow coming from the filter in the reverse direction.
Claim 2
Dependent Claim
261 words
A self-cleaning filter system for the flow of fluid from a source of impure fluid to a consumer of filtered fluid at a pressure lower than that at the source, which comprises a pure fluidic bistable switch having, two opposite wall surfaces confining between them a passage forming a main-flow inlet for connection to such source at one end, and branched at its other end to form two main flow outlets connected to said main-flow inlet in parallel to each other as to enable the Coanda effect of said wall surfaces to alternatively establish a first stable flow condition in which substantially all said main flow will pass through one, and a second stable flow condition in which substantially all said main flow will pass through the other main-flow outlet, and two control inlets having jet-forming means for the respective production of fluid jets acting upon the flow from the main-flow inlet to respectively change the main flow from said first stable flow condition to said second stable flow condition and vice versa, two filter elements respectively connected to said two main-flow outlets, and two pure-fluidic reverse-flow switches each having a through passage and a spill outlet, said through passages of the two reverse-flow switches being respectively interposed in the connection between each main-flow outlet of the bistable device and the associated filter, and each reverse-flow switch being so arranged as to permit flow from the bistable device through said through passage to the filter but to divert to said spill outlet flow coming from the filter in the reverse direction.
Claim 3
Dependent Claim
38 words
A filter system as claimed in claim 1, which includes fluidic means automaticallY effecting the change-over of the bistable device in response to an increase in the resistance of the filter through which said main flow is conducted.
Claim 4
Dependent Claim
73 words
A filter system as claimed in claim 2, wherein said fluidic means comprise, for the flow through each main-flow outlet, a by-pass conduit interconnecting the inlet of the bistable device with a point between the reverse-flow switch and filter connected to said main-flow outlet, said bypass conduit including a restrictor and being connected to that control jet of the bistable amplifier which tends to divert the main flow to the other main-flow outlet.
References Cited (Backward Citations)
US3157131A
Cited
US3388799A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |