US3744446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Propeller driven boats
Assignee: Individual
•
Filing: 1971-12-23
•
Granted: 1973-07-10
•
Expires: 1991-12-23
Abstract
Abstract The hull of a propeller driven planing boat powered by an inboard engine is provided on the underside thereof with a channel extending longitudinally of the hull from the stern towards the bow, with the channel being of maximum depth at the stern to accommodate a propeller therein adjacent the stern, said channel widening and becoming shallower until it merges with the hull surface, and with the cross-sectional perimeter of the channel being of the same length along the length of the channel so that the surface area of the channel remains constant as a wetted area throughout the length of the channel. This provides a contour of the channel adapted to ensure that water will flow, during motion of the hull, through the channel without producing eddy currents, cavitation, aeration or other fluid flow effects likely to affect the operating efficiency of the propeller in the channel.
Inventors
- 👤 F Gibbins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:06
CPC Classifications
B; B63; B63H; B63H5/00; B63H5/07; B63H5/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
82 words
A boat hull including on the underside thereof a channel extending longitudinally of the hull from the stern towards the bow, the channel being of maximum depth at the stern, a propeller supported to operate in said maximum depth section of the channel, said channel widening and becoming shallower until at its forward end it merges with the hull surface, and with the cross-sectional perimeter of the channel being of the same length at all points along the length of the channel.
Claim 2
Dependent Claim
82 words
A boat hull including on the underside thereof a channel extending longitudinally of the hull from the stern towards the bow, the channel being of maximum depth at the stern, a propeller supported to operate in said maximum depth section of the channel, said channel widening and becoming shallower until at its forward end it merges with the hull surface, and with the cross-sectional perimeter of the channel being of the same length at all points along the length of the channel.
Claim 3
Dependent Claim
48 words
A boat hull as claimed in claim 1 and wherein the maximum depth section of the channel is mainly hemi-spherical in cross-section and from this section progressively widens and becomes shallower and at its forward end it is widest and shallowest to merge with the boat hull surface.
Claim 4
Dependent Claim
62 words
A boat hull as claimed in claim 2 and wherein the surface area of the channel when plotted onto a plane surface resolves into a rectangle having a width equal to the widest part of the channel and a length greater than the width so that the channel surface area remains constant as a wetted area throughout the length of the channel.
Claim 5
Dependent Claim
27 words
A boat hull as claimed in claim 1 and wherein the channel for a single propeller craft is in axial alignment with the keel of the boat.
Claim 6
Dependent Claim
28 words
A boat hull as claimed in claim 1 and wherein a channel is provided on each side of the keel and parallel thereto for a twin propeller craft.
Claim 7
Dependent Claim
64 words
A boat hull as claimed in claim 1 and wherein twin rudders are provided one on each side of the stern end of the channel said rudders having portions extending forwardly of the rudder pivot bearings, said portions increasing the operating faces of the rudders and also provide reverse acting forces assisting operation of the rudders during movement of the boat in the water.
Claim 8
Dependent Claim
112 words
A boat hull including on the underside thereof a channel extending longitudinally of the hUll from the stern towards the bow, a maximum depth section of the channel at the stern end thereof, a propeller supported to operate in said maximum depth section which is hemi-spherical at its base and of a depth at least equivalent to the propeller diameter, said channel forwardly of the propeller becoming wider and shallower until at its forward end it merges with the hull surface, and with the contours of the channel being arranged so that the cross-sectional perimeter of the channel is of the same length at all points along the length of the channel.
Claim 9
Dependent Claim
112 words
A boat hull including on the underside thereof a channel extending longitudinally of the hUll from the stern towards the bow, a maximum depth section of the channel at the stern end thereof, a propeller supported to operate in said maximum depth section which is hemi-spherical at its base and of a depth at least equivalent to the propeller diameter, said channel forwardly of the propeller becoming wider and shallower until at its forward end it merges with the hull surface, and with the contours of the channel being arranged so that the cross-sectional perimeter of the channel is of the same length at all points along the length of the channel.
Claim 10
Dependent Claim
26 words
A boat hull as claimed in claim 7 and wherein said propeller is positioned at an intermediate point in the maximum depth section of the channel.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |