US4176613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fixed geometry water jet inlet for a surface effect ship
Assignee: Rohr Inc
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Filing: 1977-11-25
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Granted: 1979-12-04
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Expires: 1997-11-25
Abstract
Abstract A water jet inlet as used in a surface effect ship, cavitation free environment is provided of a fixed round or rectangular inlet geometry, within the confines of inlet velocity ratios pertaining to the ship velocity immersion design profile. An additional embodiment is disclosed that enables the instant invention to operate at a range of drop fractions, including negative drop fractions, and allows for a truly flush inlet, resulting in minimizing the drag of the ship and potential ingestion of large floating debris.
Inventors
- 👤 Michael A. Rickards
- 👤 Richard K. Ruhe
- 👤 Leonard Meyerhoff
- 👤 James M. Hook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:43
CPC Classifications
B; B60; B60V; B60V1/00; B60V1/14; B60V1/15; B60V1/04; B60V1/046; B60V1/11; B60V3/00; B60V3/06; B60V3/065; B63; B63H; B63H11/00; B63H11/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
140 words
A fixed geometry water inlet duct for a surface effect ship for providing a constant cavitation free supply of water to a propulsion jet pump, said ship having side fences, each of said side fences having a curvilinear bottom hull surface, said inlet duct comprising: a ramp roof portion extending rearward and forming a continuation of the bottom hull surface and extending rearward to the inlet of said jet pump; a duct floor portion extending from a position intermediate the forward and aft portions of said ramp roof portion and extending to said inlet of said jet pump, said ramp roof portion and said duct floor portion being continuous for the length of said duct floor portion; an enlarged lip portion positioned at the leading edge of said duct floor portion; and a ventilation cavity adjacent said enlarged lip portion.
Claim 2
Dependent Claim
140 words
A fixed geometry water inlet duct for a surface effect ship for providing a constant cavitation free supply of water to a propulsion jet pump, said ship having side fences, each of said side fences having a curvilinear bottom hull surface, said inlet duct comprising: a ramp roof portion extending rearward and forming a continuation of the bottom hull surface and extending rearward to the inlet of said jet pump; a duct floor portion extending from a position intermediate the forward and aft portions of said ramp roof portion and extending to said inlet of said jet pump, said ramp roof portion and said duct floor portion being continuous for the length of said duct floor portion; an enlarged lip portion positioned at the leading edge of said duct floor portion; and a ventilation cavity adjacent said enlarged lip portion.
Claim 3
Dependent Claim
33 words
The invention as defined in claim 1, wherein said ramp roof portion is longitudinally curvilinear and has at least three different radii of longitudinal curvature between said bottom surface and jet pump inlet.
Claim 4
Dependent Claim
31 words
The invention as defined in claim 2, wherein the smallest of said at least three radii is intermediate said bottom surface and the jet pump inlet adjacent said enlarged tip portion.
Claim 5
Dependent Claim
28 words
The invention as defined in claim 1, wherein said duct floor portion between said enlarged lip portion and the jet pump inlet is substantially rectilinear in longitudinal cross-section.
Claim 6
Dependent Claim
25 words
The invention is defined in claim 1, wherein said inlet converges aft of said enlarged lip portion and then diverges toward the jet pump inlet.
Claim 7
Dependent Claim
18 words
The invention as defined in claim 1, wherein the forward surface of said enlarged lip portion is curvilinear.
Claim 8
Dependent Claim
14 words
The invention as defined in claim 1, wherein said inlet is curvilinear in cross-section.
Claim 9
Dependent Claim
16 words
The invention as defined in claim 1, wherein said ventilation cavity is open to the atmosphere.
Claim 10
Dependent Claim
18 words
The invention as defined in claim 1, wherein said ventilation cavity is open to the cushion air supply.
Claim 11
Dependent Claim
27 words
The invention as defined in claim 1, wherein a plurality of passageways are provided between said ventilation cavity and the leading edge of said enlarged lip portion.
Claim 12
Dependent Claim
20 words
The invention as defined in claim 10, wherein said passageways terminate at said leading edge of said enlarged lip portion.
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) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |