Ships – Hull or hull adjunct employing fluid dynamic forces to...
Reexamination Certificate
1999-02-08
2001-01-16
Sotelo, Jesus D. (Department: 3617)
Ships
Hull or hull adjunct employing fluid dynamic forces to...
Reexamination Certificate
active
06173670
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of aluminum boat hulls, and in particular to aluminum boat hulls having a bottom and transom configured to maximize performance.
BACKGROUND OF THE INVENTION
Concave bows, keels, strakes that extend longitudinally, off-sets or jack plates, and vee shaped hulls are not new to boats intended to be powered by outboard engines. However, each of these items is used in a separate, particular way.
For example, providing a keel on a boat is known to increase its tracking ability, but it is also known to provide drag and generally is considered to decrease speed. Therefore, few “performance” or high speed boats have keels.
Strakes are normally used for two reasons, namely to increase the strength of a boat bottom, and when disposed with one strake surface parallel to the water surface, to give lift. In aluminum boats, in particular, strakes are generally tapered at the rear end so that they do not prevent bow lift, or if not tapered at the rear end, then the transom is formed with a tapered corner to insure some lift but this increases so called “draft”.
“Set-backs” are somewhat common for performance bass boats with so-called pad hulls. Pad hulls have narrow (8-14 inches) centrally located longitudinal bottom surfaces that are flat or only slightly “veed” or concaved. These bottom surfaces provide a minimum water contact surface area and thereby enhance the boat speed. However, on larger boats, the “set-back” is normally provided by a separate bracket that sits the engine 12 or more inches behind the hull, and not by a set back of 4-8 inches that is formed integrally with the boat.
Vee hulls are common in outboard motor boats because they are known for their softer ride and “rough water” abilities. However, aluminum vee shaped hulls with performance characteristics that approach fiberglass, are not known to the outboard motor boat market.
If there was such a thing as a performance vee hull that could be made by “high speed” (rather than custom hand crafted) production techniques before the present invention, then its contours were such that the hull either had to be made of molded fiberglass or made with sophisticated aluminum “stretch forming” techniques. Molding of a hull with fiberglass is a manual operation including applying layers of fiberglass into a mold of any desired configuration and such application takes extended periods of time and presents numerous environmental problems.
The present state of the art wisdom is: keels provide drag, strakes either are tapered at the back or the hull has “cut corners”, jack-plates on vee hulls commonly sit far back (not 4-8 inches), concave bows are for pad boats (not for severe 15 degrees or more vees), and normal aluminum production techniques are not suited to economically provide a performance vee.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a performance vee shaped hull that can be made with conventional aluminum manufacturing techniques on a relatively economical basis. The hull uses the lift of a concave bow, the off-setting “hold down” of strakes without lift characteristics, the tracking and drag of a keel and an integrally formed off-set motor mount, projecting rearwardly only 4-8 inches from a full transom to produce a “severe vee” hull configuration (10-15 degrees inclination per side, 20-30 degrees total vee shape).
The hull of the present invention has a curved, reverse or concave flared bow. A bottom surface of the hull terminates at a rear edge. Behind the rear edge is a set-back section. A transom extends across the rear of the boat, and, in a preferred embodiment, is relatively flat all the way across. The set-back section extends rearwardly 4-8 inches from the transom and has a bottom surface that is above the bottom edge of the transom, preferably about 3-6 inches. However, this bottom edge, while still above the bottom surface of the hull at least 3″ can be “V” or curved in shape.
Along the center of the hull bottom is the keel. On opposite sides of the keel, the bottom surface of the hull is formed with parallel longitudinal strakes that extend the full length of the bottom surface, rearwardly of the bow area, with a constant cross-section. These strakes are “U” shape in cross sectional contour but can be vee or “L” shaped. The two aluminum sections which include the strakes and which are welded to a central keel, extend at an angle of 10-15° to the horizontal, to form a V-shaped hull of 20-30° to the horizontal.
An outboard engine is mounted on the set-back section to propel the hull. If desired, wedge shaped lips can be provided at the outer edge of the hull bottom to minimize any excessive bow lift caused by the strakes during initial application of power by the outboard engine.
The hull of the present invention can be used in a so called “bass boat” arrangement or “bay boat” arrangement. In a 19 foot long configuration, with a 66 inch wide bottom, the boat hull of the present invention can run between 53 and 60 miles per hour when powered by a stock 115 horsepower engine, and will handle turns and rough water beyond expectations.
A boat hull according to the present invention, adapted to be powered by an outboard engine, is made from aluminum by conventional production techniques and equipment. Aluminum allows the boat to be used in “abusive” environments such as rocky or reef areas since impact to aluminum will cause little or no damage when impact to fiberglass would cause fractures.
The boat hull, because of its hydrodynamic and aerodynamic configuration, provides superior handling, and turning performance characteristics when compared to shallow vee or pad hulls. A unique combination of aerodynamic lift from the concave bow, set-back of the outboard engine to maximize hydrodynamic water flow to the propeller, and severe vee hull shape, with a full transom, work together with longitudinal strakes extending to the rear bottom edge and a central keel to give unexpected, superior performance characteristics.
It is therefore another object of the present invention to provide a vee shaped aluminum hull having a central keel, with strakes extending from the bow to the stern of the hull and including a set back section for supporting an outboard motor.
It is still yet another object of the present invention to provide a vee shaped aluminum hull made of two sections of aluminum welded to a central aluminum keel and having three parallel extending strakes in each aluminum hull section, extending from the bow to the stern with a constant cross section, and including a set back section extending 4 to 8 inches rearwardly from the transom and approximately 3 to 6 inches above the lowermost edge of the transom.
It is still yet another object of the present invention to produce a bass-type or bay-type aluminum vee shaped keel with the angle of the vee shape being in the range of 15 to 30 degrees and including parallel extending strakes terminating at a rear edge of a transom above which is located a set back section for mounting of an outboard motor.
These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings.
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patent: 5322030 (1994-06-01), Brehmer
patent: 5676080 (1997-10-01), Allen
patent: 5685253 (1997-11-01), Alexander
Xpress, Since 1965 The Original All Welded Boat, 1998.
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Sea Ark Boats, Aluminum Jon Boats, Super Jons, Fishing Boats & Deck Style Boats.
Crestliner, The Leader by Innovation.
Duracraft Marine Corporation
Jacobson Price Holman & Stern PLLC
Sotelo Jesus D.
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