Ships – Keels
Reexamination Certificate
2000-06-26
2002-06-04
Swinehart, Ed (Department: 3617)
Ships
Keels
Reexamination Certificate
active
06397771
ABSTRACT:
BACKGROUND THE INVENTION
This invention relates to water crafts and particularly to sailboats having keel structures for improving the lateral stability of the sailboats when pointing the sailboats. The lateral stability provided by the keel structure enables a sailboat to better hold its course.
The keel structure includes a keel member and a wing member attached thereto. In one embodiment the keel member is slidably attached to the sailboat, and the wing member is fixed to the keel member. In a second embodiment the keel member is pivotally attached to the sailboat, and the wing member is pivotally attached to the keel member.
Keels are commonly provided on the bottom of sailboats to add stability to the sailboats by preventing the sailboats from heeling. Larger sailboats have been provided with fixed keels, while smaller sailboats have been provided with vertically moveable keels or dagger boards. While these fixed keels and dagger boards do increase the stability of the sailboats to which they are attached, the stability is not always sufficient to allow these sailboats to hold their course when pointing, and especially when pointing high, i.e. sailing close to the wind. Additionally, because of the fixed keels of the larger sailboats, these sailboats cannot be sailed in shallow water. Also, in deeper water the size of the fixed keels limits the speed of the sailboats. Whether sailing for recreational purposes or competitive purposes, the most enjoyment can be obtained when the sailboat is stable and versatile, such that it can be controlled as desired by its captain in changing water depths and wind conditions.
OBJECTS OF THE INVENTION
It is a primary object of the invention to improve the lateral stability of a sailboat when pointing the sailboat.
It is another object of the invention to enable a sailboat to easily be sailed in shallow water.
It is a further object of the invention to enable a sailboat to be sailed in deeper water at increased speeds.
SUMMARY OF THE INVENTION
The water craft of the present invention is preferably a sailboat provided with a wing keel. In a first embodiment of the invention the wing keel comprises a keel member that is pivotally attached to the bottom of the sailboat, and a wing member that is pivotally attached to the bottom of the keel member. As the sailboat is being sailed the force of the water will pivot the keel member towards the bottom of the sailboat, and also pivot the wing member such that it is generally parallel to the water surface. When the wing member pivots such that it is generally parallel to the water surface, a greater generally horizontal surface area is presented to the water, whereby the sailboat is provided with enhanced stability in all water depths and wind conditions while performing sailing maneuvers, such as pointing. Also, because the keel member pivots towards the bottom of the sailboat the draft is reduced, whereby the sailboat can be sailed in shallow water. This reduced draft also enables the sailboat to be sailed at greater speeds in deeper water.
In a second embodiment of the invention the sailboat includes a vertically adjustable keel member having a wing member fixed to the bottom thereof. The wing member is fixed to the bottom of the keel member such that the wing member extends generally parallel to the water surface during sailing of the sailboat, whereby stability of the sailboat is improved as with the first embodiment. And, because the keel member is vertically adjustable the draft can be reduced, whereby the sailboat can be sailed in shallow water and can also be sailed in deeper water at a greater speed, like in the first embodiment
REFERENCES:
patent: 83420 (1868-10-01), Stoner et al.
patent: 1061826 (1913-05-01), Didlake
patent: 2553372 (1951-05-01), Hurst
patent: 2569270 (1951-09-01), Wilson
patent: 3324815 (1967-06-01), Morales
patent: 4686922 (1987-08-01), Burroughs
patent: 5152238 (1992-10-01), Page
patent: 6019059 (2000-02-01), Kelsey
patent: 2942071 (1981-04-01), None
patent: 2563177 (1985-10-01), None
patent: 1581627 (1980-12-01), None
patent: WO 89/09159 (1989-10-01), None
Levi Clark
Martin James B.
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