US3678689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Submerged multistage pump usable as propulsion unit
Assignee: Individual
•
Filing: 1970-09-04
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Granted: 1972-07-25
•
Expires: 1990-09-04
Abstract
Abstract A submerged pump comprising a plurality of coaxial impellers arranged in series in an elongated casing having an inlet at one end and an outlet at the other and providing a pump chamber for each impeller and connecting passageways between the pump chambers, has additional inlets opening from the exterior of the casing into the connecting passageways between successive pump chambers. The velocity of liquid being pumped is increased by successive impellers and the volume of the liquid is increased by the liquid drawn in through the additional inlets. When used as a submerged propulsion unit the pump is of streamlined configuration and is surrounded by a shroud. Forward and reverse propulsion are selectively provided by directing the pump discharge to rearwardly or forwardly directed nozzles. The pump can also be used as a bow-thruster in a vessel.
Inventors
- 👤 Samford P Ishiwata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:52
CPC Classifications
F; F04; F04D; F04D1/00; F04D1/06; F04D1/10; B; B63; B63H; B63H11/00; B63H11/02; B63H11/04; B63H11/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
202 words
A submerged propulsion unit comprising an elongated streamlined casing having forwardly facing front inlet at the forward end and a jet discharge outlet at the rearward end, a rotatable shaft extending longitudinally of said casing, a plurality of impellers fixed on said shaft and spaced axially from one another, means in said casing defining a pump chamber for each of said impellers, intermediate passageways connecting successive pump chambers with one another, an inlet passage connecting the inlet of said casing with the first of said plurality of pump chambers and a discharge passage connecting the last of said plurality of pump chambers with said outlet of said casing, said pump casing having at least one intermediate inlet which faces forwardly of said casing and is connected with a respective intermediate passage, said impellers upon rotation by said shaft drawing fluid in through said front inlet and said intermediate inlet, impelling it rearwardly with progressively increasing velocity and discharging it from said outlet, the volume of said fluid being progressively increased by additional fluid drawn in through said intermediate inlet and said impellers increasing in size from the front toward the rear of said casing to handle said progressively increasing volume of fluid.
Claim 2
Dependent Claim
202 words
A submerged propulsion unit comprising an elongated streamlined casing having forwardly facing front inlet at the forward end and a jet discharge outlet at the rearward end, a rotatable shaft extending longitudinally of said casing, a plurality of impellers fixed on said shaft and spaced axially from one another, means in said casing defining a pump chamber for each of said impellers, intermediate passageways connecting successive pump chambers with one another, an inlet passage connecting the inlet of said casing with the first of said plurality of pump chambers and a discharge passage connecting the last of said plurality of pump chambers with said outlet of said casing, said pump casing having at least one intermediate inlet which faces forwardly of said casing and is connected with a respective intermediate passage, said impellers upon rotation by said shaft drawing fluid in through said front inlet and said intermediate inlet, impelling it rearwardly with progressively increasing velocity and discharging it from said outlet, the volume of said fluid being progressively increased by additional fluid drawn in through said intermediate inlet and said impellers increasing in size from the front toward the rear of said casing to handle said progressively increasing volume of fluid.
Claim 3
Dependent Claim
14 words
A fluid pump according to claim 1 in which said intermediate passageways are annular.
Claim 4
Dependent Claim
14 words
A fluid pump according to claim 2, in which said intermediate inlets are annular.
Claim 5
Dependent Claim
35 words
A fluid pump according to claim 2, in which each said annular intermediate passageway leads from a radially outer portion of a preceding pump chamber to a radially inner portion of a succeeding pump chamber.
Claim 6
Dependent Claim
58 words
A propulsion unit according to claim 1, comprising a shroud surrounding and spaced from said casing to define an annular passage between said shroud and casing, said intermediate inlet opening forwardly from said annular passageway into said intermediate passageway, whereby fluid is forced into said intermediate inlet by the ram effect of fluid flowing through said annular passage.
Claim 7
Dependent Claim
73 words
A propulsion unit according to claim 5, in which a tail ring surrounds and is spaced from a rear end portion of said casing to define an annular passage between said casing and said tail ring and to induce a fast-moving flow of fluid in the space between the shroud and casing to increase the ram effect on said intermediate inlet or inlets and thereby draw more water in through said intermediate inlets.
Claim 8
Dependent Claim
29 words
A propulsion unit according to claim 1, in which said outlet comprises a central rearwardly directed nozzle and a plurality of rearwardly directed nozzles arranged around said central nozzle.
Claim 9
Dependent Claim
61 words
A propulsion unit according to claim 1, in which said outlet comprises at least one rearwardly directed nozzle and at least one forwardly directed nozzle, and in which flow directing means is operable to direct discharge fluid selectively to said rearwardly directed nozzle to provide a forwaRd propulsion force or to said rearwardly directed nozzle to provide a rearwardly propulsion force.
Claim 10
Dependent Claim
53 words
A propulsion unit according to claim 1, in which said outlet comprises a nozzle directed laterally of said pump to provide a laterally directed reaction force from the discharge of fluid from said nozzle, said nozzle being rotatable about the longitudinal axis of said pump to control the direction of said reaction force.
Claim 11
Dependent Claim
24 words
A propulsion unit according to claim 16, in which a forwardly facing annular intermediate inlet is provided opening into each of said intermediate passageways.
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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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |