Patent Application
20170029075
Not Applicable.
Not Applicable
Not Applicable.
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR 1.71(d).
Field of Endeavor
The present invention relates to apparatuses, systems and methods for improved boat of both mono-hull and multi-hull designs. More particularly, the invention relates to boat hulls having a keel configured as an inverted foil providing better fuel economy, maneuverability, a smoother ride at both high and low speeds, less side to side rolling motion when stationary in waves and greater weight carrying capacity.
Background Information
Boat hull design has been a constantly evolving field of art for thousands of years. In particular, the development of non-wind propulsion systems, material science and other technologies, has contributed to many advances in hull design over the past two hundred years.
Flat-bottom boats have a large, substantially flat hull bottom, making them very stable in calm weather. Characteristically, however, the flat, broad bow area creates a rough ride. These boats are usually limited to low horsepower motors because they do not generally handle well at high speed. Flat-bottom boats are also well suited for shallow water.
Early in nautical history, boats were powered by wind or by hand-stroked oars. Early boat designers found that boats went faster, and were easier to steer, if the bow was pointed. They also soon discovered that by lowering the center of gravity, the sailing boats had better stability, and usually kept the boat upright even in bad weather.
With the advent of mechanical power came boats with “planing” hulls, which lift the boat partially out of the water to skim on the surface allowing the boat to be operated at higher speeds for the same power. “Displacement” hulls push through or cruise through the water instead of skimming on the surface and are not able to operate at the higher speeds of a planing hull.
“Semi Displacement” hulls act in a manner part way between Displacement hulls and Planing hulls. At slow speeds they are more efficient than Planing hulls but not as efficient as Displacement hulls, while at medium speed they are more efficient than both Displacement and Planing hulls. Semi Displacement hulls are not usually able to operate at the high speeds typical of Planing hulls but are able to operate efficiently at higher speeds than a Displacement hull.
The V bottom boat is probably the most common hull design for planing hulls. Most manufacturers of performance boats built today use variations of this design. This design offers a reasonable ride in rough water as the pointed bow slices through the water forward and the V-shaped bottom softens the slamming of the boat in waves. The angle of the V is called “deadrise”. A sharper V has more deadrise. Some “V”-bottom boats have a small, local flat surface at the very bottom of the aft end called a “pad.” This pad creates a little more lift which increases top speed but at the sacrifice of a little softness in the ride. Typically, a V hull boat has no real keel, simply a sharp angle at the bottom point of the V.
A chine in V bottom planing or semi-displacement power boat hull forms refers to the hard corner or edge at the intersection between the hull bottom and the hull side.
With sailboats, it is common to have a rounded hull with no strakes or chines. A keel is often employed. However, the keel of a sailboat generally is generally deep vertically in proportion to the overall depth of the hull. On modern designs, it does not typically run the length of the boat.
Boats having a flatbottom, are stable at low speed while also being maneuverable and provide a large displaced volume for a given draft, thus accommodating more weight. Flatbottom boats typically have no keel.
A deep V hull provides a relatively smooth ride at high speed. However, at low speed a deep V hull is very inefficient. Furthermore, at low speeds, a deep V hull is less stable, less maneuverable and tends to roll side to side to a high degree when side on to the waves.
Many attempts have been made to design hulls that combine features of flatbottom, round and/or deep V hulls in an effort to design hulls exhibiting the advantages of each.
The purpose of a keel, fin, or centerboard is to provide resistance to making leeway; in effect, to keep the yacht from sliding sideways through the water due to wind pressure on the sails. Various shapes of underwater plane have been in and out of style over the past 150 years. Keels are generally not considered particularly necessary for powered boats, including V hull boats because they are not subject to the lateral forces caused by wind against a sail, there is also no need to use a keel for counteracting these forces to stabilize a boat. Nonetheless, keels have from time to time been incorporated into various powered boats.
The deep, full keel has been used since at least the mid-1800s for the shoal-water areas by centerboard craft. These cover such working types as the sharpies, Cape Cod catboats, Chesapeake Bay oyster skiffs and the like.
Until the mid 20th century, typical offshore yachts keels similar to those of a sailing fishing craft. They had a long, full keel with deep forefoot and fairly vertical sternpost. This shape provides directional stability, ease of steering, and the ability to heave to in heavy weather. However, these keels also resulted in slowness in stays, excess wetted surface and an inefficient lateral plane shape that has excess leeway.
To overcome these deficiencies, a modified full-keel form was designed which provided generally good handling and directional stability plus reduced wetted surface, compared to a true full-keel. The yachts can perform well in all conditions and, as they are generally of heavier displacement than contemporary ballasted-fin boats, they do not give away much in light air, despite the added wetted area.
Modern keels are generally designed in a manner similar to those of airplane wings. The maximum thickness of the keel is usually recommended to be located about 35% of the aft of the leading edge. In addition, the leading edge should be elliptical with the trailing edge slowly tapering to a point. This is in keeping with the standard designs of airfoils. It has become the industry standard to use keels having a foil-based design according to NACA standards.
In view of the foregoing, there is a need to provide a hull design that performs well at both high and low speeds. It is therefore desirable to provide a hull combining improved performance and ride comfort of any of the existing hulls at speed and in waves and improved comfort of any of the existing hulls at slow speed in waves and when stationary in waves.
Accordingly, the primary object of the present invention is to provide a boat hull that provides a smooth ride at both high and low speeds with good fuel economy and maneuverability.
A high and moderate speed boat hull incorporates a keel running the center line of the hull starting 20 to 25% aft of the bow continuing aft 75 to 80% from the bow. The hull has a larger V shaped forward section twisting and flattening out running aft to a much lesser of a V with combinations of flat keel pad and ellipsoidal shaped areas. The keel provides both lift and lessens impact in rough water. The keel has a convex shape vertically and is shallow compared to any other keel. the keel starts thin and is narrow widening aft and tapers gently back to a point with an angel rising aft and up to the hull. This aft shape of the keel directs or allows the water to flow naturally back together over the flat keel pad to create solid water to feed to the engine propeller or propellers. The flat keel pad has two purposes: 1. a dedicated support for the vessel's riding or planning angle. 2. Is it is actually a step and allows the vessel to pivot at high speed and at all speeds giving the vessel greater maneuverability. The V port and starboard of the keel is the area feeding the lifting strakes. The lifting strakes works with the keel to provides positive lift and continues to create the softness of the ride these areas provide. The lifting strakes are shaped in a triangular manner pointing downward and has a radios inside of the lifting strake helping to create the curl of the natural shape of waves both providing lift and softness of the ride in a choppy or rough sea. Outside the lifting stakes continues the genital ellipsoidal shape of the hull and feeds the water out and aft. The spoilers also provide lift both forward in the lager V area and moving aft to the chine flats.
The spoilers also provide softer looser water or soiled water to the chine flats aft relieving friction of wetted surface of the hull. The chine flatsare wider than most of any hull designs. The chine flats provide stability at rest and on plane at high speed and in a side rougher sea. The chine flats also provide a positive buoyancy giving and assisting the keeland the lifting strakes and the hull a direct attitude from rest to a full plane without squatting, digging or typically raising the bow high out of the water which also allows the vessel to reach a plane and high speed in very shallow water. The chine flat has a step 5 to 10% forward of the transom relieving friction of the wetted surface of the hull. The chine flats are assisted by the bracket or extension which is also a step. The bracket has a large flat bottom angling downward aft of the transom creating more assist in planning as a large trim tab.
The bracket adds buoyancy to support the weight of engine or engines. The bracket provides positive lift in a following sea lifting up on the inside of the wave and moving the vessel forward decreasing or eliminating the sea engulfing the engine or engines and or sinking the vessel. The bracket's large flat area adds additional stability supporting the chine flats in the side to side motion laying to in large seas preventing violent rocking motion of this vessel, the bracket is also a step allowing this vessel design to pivot over the water aft of the transom and as the bracket dose not touch the water at speed or plane it does not create drag at speed.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims. There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
Disclosed is a hull design that improves the stability of a boat at low speed and efficiency at high speed. The forward region of the hull may have a bulbous, i.e. ellipsiodal, area that may be centered around the chine within the impact zone of the boat. The impact zone is the area or region of the hull impacted by water projecting upward due to the hull moving through water and is generally in a region extending from about 15% to about 35% down the length of the bottom of the hull. Modified chines and strakes may by combined to reduce drag at lower speeds typical of a flatbottom boat while also having the stability of a deep hull boat at higher speeds. Lifting strakes, or spoilers, may also contribute to reduce drag. An aft centerline pad may also be incorporated into the hull design.
The hull may also have a mid and aft ellipsoidal fullness aft of the forefoot and forward ellipsiodal fullness. The ellipsoidal fullness may continue to a lesser extent all the way to the transom. Without being bound by theory, the inventor believes that the mid and aft ellipsiodal fullness may work synergistically with the forefoot and forward ellipsiodal fullness to allow for a more natural water flow and makes for a smoother ride in large chop conditions.
The chine near the bow may be of a conventional design, but may include a bulge or fullness in the impact zone. Aft of the bow, in the area at the aft end of the forefoot and forward ellipsiodal fullness, the chine flat may become wider and may sweep around the mid and aft ellipsoidal fullness. The deadrise angle of the hull in this area may gradually flatten until it becomes a continuation of the chine flat as one wide surface on each side of the hull. This wide chine flat may continue aft with a slight negative deadrise angle. The wide chine flat may vary in deadrise and width, and may be stepped. The hull and chine flat in accordance with the invention may create extremely high levels of stability both at speed and when stationary in wave and cross wave conditions.
A keel may begin at a point aligned with the impact zone and extend aft along the centerline to a point near the hull's center of gravity. The keel may be shallow keel and extend aft widening along a convex path and having concave sides. The keel may blend into the hull with a large radius. The keel may have a tear drop shape similar to an airfoil, but in a direction opposite to a NACA keel, i.e., the opposite of a typical foil keel design. The aft end of the keel may taper to a fine section to promote clean water flow. The keel may promote natural water flow, and may enhance slow speed and at rest stability especially in cross waves, and works together with the forward ellipsiodal fullness and the mid and aft ellipsoidal fullness to create a smoother ride in large chop conditions. A flat centerline pad may provide lift at speed and is also used to control planing attitude in extreme conditions.
On each side of the hull there may be one or more lifting strakes also to be known as spoilers. The outboard edges of the spoilers may be lower than the inboard edges (negative deadrise) and the inboard and outboard edges may be blended into the hull with a radius on each edge. Without being bound by theory, the spoilers may create lift and may simultaneously interact synergistically with the keel and with the wide aft chine flat to create a smoother, more stable ride in large chop conditions and in slow speed or when stationary in cross wave conditions.
The boat hull 100 has a bow 112 and stem 114. Those skilled in the art will appreciate that the term stem is used to refer to the leading edge of a boat hull. The hull 100 has a total length defined by the bow 112 and the transom 116. The bottom 118 of the boat hull 100 is generally defined as the portion of the hull 100 below the chine 182. The length of the bottom 118 is generally defined as the distance between the transom and the point 115 where the stem 114 intersects the chine 182. Generally, when identifying a position on the hull 100 by the approximate percentage of the distance along the hull length, it is in reference to the length of the hull bottom 118 below the chine.
The keel 120 is aligned with the centerline 122 of the hull 100. In this embodiment, the keel begins at a point on the hull bottom 118 about 20-25% aft of the bow and continues aft to a terminal end 124 to a point about 75-80% from the bow 110. Without being bound by theory, the inventor believes that the keel 120 provides both lift and lessens impact in rough water.
The bottom 118 of the hull 100, for clarity in defining certain aspects of the invention, may be characterized as having regions. The regions of the bottom 118 between the keel 120 and the lifting strake 140 is referred to herein generally as the medial region 130. The region of the bottom 118 between the lifting strake 140 and the spoiler 170 is referred to herein as the intermediate region 160. The region of the bottom 118 between the spoiler 170 and the chine 182 is referred to herein as the lateral region 184. The lateral region 184 has almost the same dead rise angle and is almost parallel to the medial 130 in the intermediate 160 regions of the hull in the forward region 110 of the hull 100. As the lateral region 184 extends aft, it twists from the forward configuration into a substantially horizontal configuration, thereby forming the chine flat 180.
Referring to
Referring to
The region 186 of the chine 182, in accordance with the principles of the invention, has a slight bulge 185 as shown in
Both the lifting strake 140 and the spoiler 170 may have a substantially triangular cross-section similar to common strakes. Optionally, the lifting strake 40 and the spoiler 170 may have a modified design with a convex lateral side 142 and a concave medial side 144 as shown in
The spoiler 170 can be seen in sections A-G as positioned within the crux formed at the medial end of the lateral region 184. The keel 120 begins near section C shown in
Inverted Foil Design of Keel
The art of keel design is almost as old as the art of boatbuilding itself.
The spoilers 170 have terminal ends 178 approximately aligned with the end of the keel 120. The terminal ends 148 do not extend as far aft as the spoiler terminal ends 178 or the keel 120. Without being bound by theory, the inventor believes that by having the spoilers 170 and the keel 120 longer than the lifting strakes 140, water flowing over the hull 100 flows more naturally, creating less friction and more stability at both low and moderate speeds.
The front of the keel 124 has a relatively sharp leading edge 224. Leading sides 129 of the keel 120 provide a very gradual increase in width of the keel 120 along its length 118. The bottom plan profile of the keel 120, i.e., the shape of the keel 120 when viewed from directly below, shows how the leading edges 129 of this embodiment are substantially straight along the first third of the length of the keel 124 and curve gradually as they approach the widest point 126 of the keel 120. The leading sides 129 however have a slightly concave transverse profile 121 as shown in
The keel 120 widens as it travels down the hull until it reaches its widest point 126. The keel 120 is located along the centerline of the keel and its leading edge 224 is located in the same region as the impact zone of the hull. That is, the keel 120 typically begins between 15% and 30% down the length of the hull bottom 118. The widest point 126 is aligned with or very close to the center of gravity of the vessel. The aft region 127 of the keel 120 extends from the widest point 126 to the trailing edge 131. The trailing sides 133 are substantially straight close to the widest point 126 and become convex as they approach the trailing edge 131. Thus, the bottom plan profile of the keel 120 when viewed from below has a profile similar to a NACA foil, but inverted. Or, as explained above, the keel 120 has a horizontal cross-sectional profile of an inverted NACA foil.
As shown in
The aft region 127 curves down in a concave manner along trailing edge 152 and joins the hull bottom 118 at or near the forward end of the centerline pad 150. In this embodiment, the keel 120 begins at about 22% down the length of the hull bottom 118, has a widest point at about 70% down the length of the bottom 118 and ends at about 75% of the length of the bottom. The forward region of the keel 124, measured from the front edge 224 to the widest point 126, is therefore about 5 times the length of the aft region 127 of the keel, measured from the widest point 126 to the end 131 where it meets the forward end of the centerline keel pad 150. In this embodiment, the widest point is located in the aft ⅔ of the keel, and may preferably be about ⅚ aft of the total length of the keel.
The flat centerline pad, or keel pad, 150 is positioned aft of the keel 120 and extends to stern of the hull bottom 118. The function of the keel pad 150 is to keep the aft end on centerline from digging in at low speeds and in turns, which allows the boat to pivot within its own length on a point at the end of the keel at any speed. It also assists in bringing an early onset to planing during acceleration. Without being bound by theory, the inventor believes that the flat keel pad 150 serves two purposes. First, it is a dedicated support for the vessel's riding or planning angle. Second, it acts as a step and allows the vessel to pivot at high speed and at all speeds giving the vessel greater maneuverability.
The medial region 130 of the hull bottom 118, defined as the area of the hull bottom on both the port and starboard sides of the keel 120 between the lifting strakes 140. The medial region 130 extends from the bow all the way aft to the transom 116. In this embodiment, it has a deadrise angle of about 40-45 degrees at the bow 112, which twists and flattens, to about 17-20 degrees at the transom 116. This medial region 130 is bounded by the keel 120 inboard and the lifting strake 140 outboard. The medial region 130 is believed to function to dynamically lift the boat at speed and to provide the primary buoyancy area of the hull when planing.
The intermediate region 160 is the strip of bottom 118 outboard of the lifting strakes 140 and inboard of the spoiler 170. The intermediate region extends from the stem 114 all the way aft to the transom 116. It has a deadrise angle identical to the medial region 130. The inventor believes that the intermediate regions 160 function to provide dynamic lift at moderate speeds as the boat gets up on plane.
The lateral region 184 is the strip of bottom 118 outboard of the spoiler 170 and inboard of the chine 182, which extends from the stem 114 to the transom 116. The portion of the intermediate region 160 located past the terminal end 178 of the spoiler 170 transitions into the lateral region 174 by a fillet, or radiused area, 174 running from the terminal end 178 of the spoiler 170 to the transom 116. The fillet 174 is believed to allow the water to flow smoothly without abrupt changes of direction from the deadrise below to the much flatter deadrise of the chine flat 180. The intermediate region 160 has a deadrise angle of about 50-52 degrees at the bow, which twists and flattens into the chine flat which has between a 5 and −5 degree deadrise. The function of Area 4 is to provide dynamic lift at sub-planing speeds in order to start the boat up on plane. Trim tab pockets are set in the aft end of Area 4 to mount adjustable trim tabs should they be needed.
When in motion, the keel 120 and the lifting strakes 140 feed water flowing through the lifting strakes 140. The keel 120 is a vertical appendage to the hull on centerline, which adds longitudinal running stability to improve yaw control while planing. This structure tapers from thin at the bottom to thicker at the top, and has a small fillet at the transition to medial region 130. The purpose of this is to provide a gentle turning of the water flow from horizontal up and over onto the deadrise angle of region 130 without abrupt changes that cause hydrodynamic drag. The keel 120 may run aft from about 20-25% aft of the bow, to 75-80% of the length from the bow where it terminates with a radiused end to aid in developing a combination of flow separation and smooth rejoining of the water as it flows from the rear end.
The lifting strakes 140 works with the keel to provides positive lift and continues to create the softness of the ride these areas provide. The lifting strakes 140 are shaped in a triangular manner pointing downward and has a radios inside of the lifting strake 140 helping to create the curl of the natural shape of waves both providing lift and softness of the ride in a choppy or rough sea. Outside the lifting stakes 160 continues the genital ellipsoidal shape of the hull 100 and feeds the water out and aft. The spoilers 170 also provide lift both forward in the lager V area and moving aft to the chine flats 180. The Lifting Strakes 140 run from the bow aft to approximately 75% of the length of the hull. These strakes run approximately parallel to the chine, instead of tracing a waterline or buttock. In the midsection the lifting strakes flatten to horizontal, which causes the boat to run at a low bow trim angle near 0 degrees. These strakes also separate water flow from the area 2 strip, reducing friction and thus provide dynamic lift when the boat is fully planing.
The spoilers 170 also provide softer looser water or soiled water to the chine flats 180 aft relieving friction of wetted surface of the hull 100. The chine flats 180 are wider than most of any hull designs. The chine flats 180 provide stability at rest and on plane at high speed and in a side rougher sea. The chine flats 180 also provide a positive buoyancy giving and assisting the keel 120 and the lifting strakes 140 and the hull 100 a direct attitude from rest to a full plane without squatting, digging or typically raising the bow high out of the water which also allows the vessel to reach a plane and high speed in very shallow water. The chine flat 180 has a step 215 5 to 10% forward of the transom 116 relieving friction of the wetted surface of the hull 100. The chine flats 180 are assisted by the bracket or 210 which is also a step.
Whereas, the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention. Descriptions of the embodiments shown in the drawings should not be construed as limiting or defining the ordinary and plain meanings of the terms of the claims unless such is explicitly indicated.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
This application is a continuation-in-part of U.S. Pat. No. 9,284,019 filed on May 16, 2014 and issued on Mar. 15, 2016, is a continuation-in-part of U.S. patent application Ser. No. 15/071,007 filed on Mar. 15, 2016, and claims priority to U.S. Provisional Application Ser. No. 61/824,339 filed on May 16, 2013, the contents of which are hereby incorporated in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61824339 | May 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14280143 | May 2014 | US |
| Child | 15294776 | US | |
| Parent | 15071007 | Mar 2016 | US |
| Child | 14280143 | US |
