US3904319A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal pumps
Assignee: Sykes Pumps Ltd
•
Filing: 1974-03-06
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Granted: 1975-09-09
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Expires: 1994-03-06
Abstract
Abstract A centrifugal liquid pump of the kind wherein an auxiliary vacuum pump assists in priming and removing unwanted gas during subsequent operation, is provided with a primary chamber to contain liquid and to receive unwanted gas which has entered the pump, an upper port in said chamber for removal of gas by said vacuum pump, a float-operated valve device to control said port, a secondary chamber connected at its upper part to said port, and a valve-controlled return passageway extending from a lower part of the secondary chamber to said primary chamber. The secondary chamber has an upper opening to said vacuum source whereby gas from said primary chamber is extracted via the secondary chamber in which entrained liquid is deposited and, on opening said secondary chamber to atmosphere, the occurring pressure differential between the chambers discharges deposited liquid in the secondary chamber through said return passageway to the primary chamber. The float-operated valve device may be arranged to open said secondary chamber to atmosphere when the valve device operates to close said port, and a manually-operable valve may be provided to admit atmospheric air to said secondary chamber and effect discharge of the deposited liquid, independently of the floatoperated valve device.
Inventors
- 👤 Harold Philip Sidney Paish
- 👤 Henry Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:26
CPC Classifications
F; F04; F04D; F04D9/00; F04D9/04; F04D9/001; F04D9/004; F04D9/005; F04D9/02; F04D9/041
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
255 words
A centrifugal liquid pump of the type wherein an auxiliary vacuum source assists in priming and removing unwanted gas during operation thereof, the centrifugal pump comprising a primary chamber which contains liquid and receives unwanted gas which has entered the pump; an upper port in said primary chamber in communication with said vacuum source for removal of gas from said primary chamber; float-operated valve means which control said upper port; means defining a secondary chamber having upper and lower parts, said upper part being disposed between and in communication with said port and said vacuum source; a return passageway extending from said lower part of the secondary chamber to said primary chamber; second valve means in said return passageway operable to permit liquid flow from said secondary chamber to said primary chamber when the pressure in said secondary chamber is greater than that in said primary chamber; said secondary chamber having an upper opening in communication with said vacuum source and through which gas from said primary chamber is extracted via said port and the secondary chamber; said float-operated valve means being operable to open said secondary chamber to atmosphere when said port is closed by said float-operated valve means in response to a predetermined rise in the liquid level in said primary chamber; whereby entrained liquid deposited in said secondary chamber is discharged to said primary chamber through said return passageway as a result of the pressure differential which occurs between the primary and secondary chambers when said secondary chamber is opened to atmosphere.
Claim 2
Dependent Claim
255 words
A centrifugal liquid pump of the type wherein an auxiliary vacuum source assists in priming and removing unwanted gas during operation thereof, the centrifugal pump comprising a primary chamber which contains liquid and receives unwanted gas which has entered the pump; an upper port in said primary chamber in communication with said vacuum source for removal of gas from said primary chamber; float-operated valve means which control said upper port; means defining a secondary chamber having upper and lower parts, said upper part being disposed between and in communication with said port and said vacuum source; a return passageway extending from said lower part of the secondary chamber to said primary chamber; second valve means in said return passageway operable to permit liquid flow from said secondary chamber to said primary chamber when the pressure in said secondary chamber is greater than that in said primary chamber; said secondary chamber having an upper opening in communication with said vacuum source and through which gas from said primary chamber is extracted via said port and the secondary chamber; said float-operated valve means being operable to open said secondary chamber to atmosphere when said port is closed by said float-operated valve means in response to a predetermined rise in the liquid level in said primary chamber; whereby entrained liquid deposited in said secondary chamber is discharged to said primary chamber through said return passageway as a result of the pressure differential which occurs between the primary and secondary chambers when said secondary chamber is opened to atmosphere.
Claim 3
Dependent Claim
139 words
A centrifugal pump as claimed in claim 1, in which said float-operated valve means comprise an upright stem which extends through said port and is raised and lowered by said float; a lower closure member secured to said stem to seat on said port when the stem is in a raised position; an upper closure member which is secured to said stem and which controls an opening in the pump housing which connects said secondary chamber to atmosphere; an intermediate valve member which slides on said stem and which closes said port when in a lower position; whereby when the stem with the upper closure member is raised by the float, atmospheric air rushes through said opening and moves the intermediate valve member to its lower position to close said port, thereby raising the pressure in said secondary chamber.
Claim 4
Dependent Claim
35 words
A centrifugal pump as claimed in claim 1, in which said second valve means controlling said return passageway has an outlet opening and said return passageway comprises a ball which seats on said outlet opening.
Claim 5
Dependent Claim
25 words
A centrifugal pump as claimed in claim 1, further comprising third valve means controlling said upper opening in the secondary chamber against entry of liquid.
Claim 6
Dependent Claim
31 words
A centrifugal pump as claimed in claim 1, further comprising manually-operable valve means for admitting atmospheric air to said secondary chamber to effect discharge of deposited liquid to said primary chamber.
Claim 7
Dependent Claim
28 words
A centrifugal pump as claimed in claim 5, in which said manually-operable valve means is operable to isolate said vacuum source for the purpose of testing the source.
Claim 8
Dependent Claim
33 words
A centrifugal pump as claimed in claim 5, in which said manually-operable valve means is spring-urged to a closed position, and said spring is adjustAble to control the liquid flow through the pump.
Claim 9
Dependent Claim
37 words
A centrifugal pump as claimed in claim 1 wherein said second valve means is operable to close said return passageway when the pressure in said primary chamber and the pressure in said secondary chamber are substantially equal.
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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) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |