US4325699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suction device for jet propulsion units for a watercraft and jet propulsion units comprising the same
Assignee: CASTOLDI SpA Soc
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Filing: 1979-11-21
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Granted: 1982-04-20
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Expires: 1999-11-21
Abstract
Abstract A suction device for a jet propeller assembly for a boat comprises a motor actuating a pump assembly and a suction conduit conveying water to the pump assembly. The suction inlet is located aft of the boat stern transom and has a rectangular minimum height cross-section with width to height ratio of 3 to 6. Preferably the suction inlet is located entirely rearwardly of the stern transom, the minimum height cross-section plane makes a 30° to 60° angle with the horizontal and the distance between the forward edge of the suction inlet and the pump inlet cross-section is not greater than twice the inlet cross-section diameter. Thus the suction device can be displaceably mounted with respect to the hull, no opening in the keel of the hull is necessary and the suction conduit can be located entirely aft of the stern transom. The propeller assembly efficiency and the wake dynamics are improved.
Inventors
- 👤 Luigi Castoldi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:08
CPC Classifications
B; B63; B63H; B63H11/00; B63H11/02; B63H11/04; B63H11/08
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
207 words
A suction device for use in a boat jet propeller assembly of the type including a motor to be mounted forward of a stern transom of a boat, a pump assembly to be mounted aft of the stern transom, and a transmission connecting said motor to said pump assembly for rotation thereof to cause pumping of water and jet discharge thereof, said suction device comprising: a suction conduit for conveying water to the pump assembly upon operation thereof, said suction conduit having a suction inlet adapted to be positioned substantially aft of the stern transom of the boat and a suction outlet adapted to be connected to an inlet cross-section of the pump assembly, said suction inlet adapted to be located in a generally horizontal plane substantially level with the bottom of the hull of the boat, said suction conduit having a minimum height cross-section having a minimum dimension in a vertical plane passing through the axis of the boat, said minimum height cross-section being rectangular and lying in a plane passing through the rear edge of said suction inlet and extending perpendicular to the axis of said suction conduit, and the ratio of width to height of said minimum height cross-section being between 3 and 6.
Claim 2
Dependent Claim
207 words
A suction device for use in a boat jet propeller assembly of the type including a motor to be mounted forward of a stern transom of a boat, a pump assembly to be mounted aft of the stern transom, and a transmission connecting said motor to said pump assembly for rotation thereof to cause pumping of water and jet discharge thereof, said suction device comprising: a suction conduit for conveying water to the pump assembly upon operation thereof, said suction conduit having a suction inlet adapted to be positioned substantially aft of the stern transom of the boat and a suction outlet adapted to be connected to an inlet cross-section of the pump assembly, said suction inlet adapted to be located in a generally horizontal plane substantially level with the bottom of the hull of the boat, said suction conduit having a minimum height cross-section having a minimum dimension in a vertical plane passing through the axis of the boat, said minimum height cross-section being rectangular and lying in a plane passing through the rear edge of said suction inlet and extending perpendicular to the axis of said suction conduit, and the ratio of width to height of said minimum height cross-section being between 3 and 6.
Claim 3
Dependent Claim
29 words
A suction device as claimed in claim 1, wherein the area of the cross-section of said suction conduit is substantially equal to the inlet cross-section of the pump assembly.
Claim 4
Dependent Claim
16 words
A suction device as claimed in claim 1, wherein said ratio is between 4 and 5.
Claim 5
Dependent Claim
23 words
A suction device as claimed in claim 1, wherein said suction inlet is positioned entirely rearwardly of the stern transom of the boat.
Claim 6
Dependent Claim
29 words
A suction device as claimed in claim 1, wherein said minimum height cross-section lies in a plane extending to the horizontal at an angle of between 30° and 60°.
Claim 7
Dependent Claim
16 words
A suction device as claimed in claim 5, wherein said angle is between 40° and 50°.
Claim 8
Dependent Claim
38 words
A suction device as claimed in claim 1, wherein the distance between the forward edge of said suction inlet and the inlet cross-section of the pump assembly is not greater than twice the diameter of the inlet cross-section.
Claim 9
Dependent Claim
21 words
A suction device as claimed in claim 7, wherein said distance is less than twice the diameter of the inlet cross-section.
Claim 10
Dependent Claim
27 words
A suction device as claimed in claim 1, further comprising means for varying the position of said suction conduit with respect to the hull of the boat.
Claim 11
Dependent Claim
30 words
A suction device as claimed in claim 9, wherein said means comprises structure for varying the angular position of said suction conduit with respect to the hull of the boat.
Claim 12
Dependent Claim
194 words
A jet propeller assembly for use on a boat, said jet propeller assembly comprising: a motor to be mounted forward of a stern transom of a boat; a pump assembly to be mounted aft of the stern transom; transmission means, connected between said motor and said pump assembly, for rotating said pump assembly to cause pumping of water and jet discharge thereof; and a suction conduit for conveying water to said pump assembly upon operation thereof, said suction conduit having a suction inlet to be positioned substantially aft of the stern transom and a suction outlet connected to an inlet cross-section of said pump assembly, said suction inlet being located in a generally horizontal plane extending substantially level with the hull of the boat, said suction conduit having a minimum height cross-section having a minimum dimension in a vertical plane passing through the axis of the boat, said minimum height cross-section being rectangular and lying in a plane passing through the rear edge of said suction inlet and extending perpendicular to the axis of said suction conduit, and the ratio of width to height of said minimum height cross-section being between 3 and 6.
Claim 13
Dependent Claim
194 words
A jet propeller assembly for use on a boat, said jet propeller assembly comprising: a motor to be mounted forward of a stern transom of a boat; a pump assembly to be mounted aft of the stern transom; transmission means, connected between said motor and said pump assembly, for rotating said pump assembly to cause pumping of water and jet discharge thereof; and a suction conduit for conveying water to said pump assembly upon operation thereof, said suction conduit having a suction inlet to be positioned substantially aft of the stern transom and a suction outlet connected to an inlet cross-section of said pump assembly, said suction inlet being located in a generally horizontal plane extending substantially level with the hull of the boat, said suction conduit having a minimum height cross-section having a minimum dimension in a vertical plane passing through the axis of the boat, said minimum height cross-section being rectangular and lying in a plane passing through the rear edge of said suction inlet and extending perpendicular to the axis of said suction conduit, and the ratio of width to height of said minimum height cross-section being between 3 and 6.
Claim 14
Dependent Claim
28 words
An assembly as claimed in claim 11, wherein the area of the cross-section of said suction conduit is substantially equal to said inlet cross-section of said pump assembly.
Claim 15
Dependent Claim
15 words
An assembly as claimed in claim 11, wherein said ratio is between 4 and 5.
Claim 16
Dependent Claim
22 words
An assembly as claimed in claim 11, wherein said suction inlet is positioned entirely rearwardly of the stern transom of the boat.
Claim 17
Dependent Claim
29 words
An assembly as claimed in claim 11, wherein said minimum height cross-section lies in a plane extending to the horizontal at an angle of between 30° and 60 °.
Claim 18
Dependent Claim
15 words
An assembly as claimed in claim 15, wherein said angle is between 40° and 50°.
Claim 19
Dependent Claim
37 words
An assembly as claimed in claim 11, wherein the distance between the forward edge of said suction inlet and said inlet cross-section of said pump assembly is not greater than twice the diameter of said inlet cross-section.
Claim 20
Dependent Claim
20 words
An assembly as claimed in claim 17, wherein said distance is less than twice the diameter of said inlet cross-section.
Claim 21
Dependent Claim
26 words
An assembly as clamined in claim 11, further comprising means for varying the position of said suction conduit with respect to the hull of the boat.
Claim 22
Dependent Claim
29 words
An assembly as claimed in claim 19, wherein said means comprises structure for varying the angular position of said suction conduit with respect to the hull of the boat.
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) | 1985-04-19 | 1985-10-19 | 1986-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-19 | 1989-10-19 | 1990-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-19 | 1993-10-19 | 1994-04-20 | $7700.00 | Window Closed / Lapsed |