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Title:
SPLIT HULL DESIGN FOR BOATS
United States Patent 3847103
Abstract:
A boat construction including front and rear longitudinally spaced depending displacement-type hull portions with the hull portions at one end of the boat comprising a pair of laterally spaced hull portions. Each of the depending hull portions is contoured, in horizontal section, to move through a fluid medium with little resistance from the medium to passage therethrough and each of the hull portions include forwardly and upwardly inclined bows.


Inventors:
TAKEUCHI R
Application Number:
05/250325
Publication Date:
11/12/1974
Filing Date:
05/04/1972
Assignee:
TAKEUCHI R,US
Primary Class:
Other Classes:
D12/310
International Classes:
B63B1/12; (IPC1-7): B63B1/18
Field of Search:
114/66
View Patent Images:
US Patent References:
3702598WATERCRAFT1972-11-14Szptyman
3611967BOAT HULL CONSTRUCTION1971-10-12Bossler
3463108AMPHIBIOUS VEHICLE1969-08-26Neumeier
3078819Boat hull construction1963-02-26Kiss
2735392N/A1956-02-21Cox
1422542Multiple-hull boat1922-07-11Creed
1041849N/A1912-10-22Myers
Primary Examiner:
Blix, Trygve M.
Assistant Examiner:
Goldstein, Stuart M.
Attorney, Agent or Firm:
Clarence A. O'Brien & Harvey B. Jacobson
Claims:
What is claimed as new is as follows

1. A boat hull including an upper longitudinally continuous hull section and fixed, longitudinally spaced, front and rear upright, fin shaped and depending displacement-type hull means, the weight of said hull in relation to the displacement of the lower portions of said displacement-type hull means being such that the water line on the hull is disposed at a level intermediate the upper and lower ends of said upright displacement-type hull means, said front and rear hull means both being constructed as integral non-shiftable portions of said hull section and with the upper extremities of said hull means merging smoothly into adjacent surfaces of said hull section, said front hull means including upstanding sharply rearwardly tapered rear extremities extending upwardly from considerably below the waterline to said upper hull section and spaced appreciably forward of the waterline forward extremities of said rear hull means, said rear hull means including upstanding sharply rearwardly tapered rear extremities and said front and rear hull means including forwardly and upwardly inclined forward extremities, at least one of said hull means comprising a pair of laterally spaced depending hull portions, each of said hull portions as well as the other hull means being contoured, in horizontal section, to move through a fluid medium with little resistance from said medium to passage therethrough.

2. The combination of claim 1 wherein said hull portions comprise said rear hull means.

3. The combination of claim 1 wherein said hull portions comprise said front hull means.

4. The combination of claim 1 wherein said hull portions are slightly downwardly divergent.

5. The combination of claim 1 wherein said hull portions include forwardly and upwardly inclined bows.

6. The combination of claim 1 wherein the other hull means comprises a single transversely centered depending hull portion and said laterally spaced hull portions are disposed on opposite sides of the longitudinal centerline of said single depending hull portion.

7. The combination of claim 6 wherein said laterally spaced hull portions comprise forward hull portions and said centered hull portion comprises a rear hull portion.

8. The combination of claim 1 wherein the other hull means also comprises a pair of laterally spaced depending hull portions.

9. The combination of claim 8 wherein said pairs of laterally spaced depending hull portions are at least slightly downwardly divergent.

10. The combination of claim 9 wherein said hull portions include forwardly and upwardly inclined bows.

11. The combination of claim 8 wherein the rearmost hull portions include lower rear marginal portions supported therefrom for oscillation about upstanding axes.

12. The combination of claim 1 wherein the rearmost depending hull means include laterally outwardly offset mounted screw-type marine propulsion means.

13. The combination of claim 1 wherein said depending hull means are generally equal in length and the spacing between the forward and rear depending hull means is between one half and one times the length of said hull means.

14. The combination of claim 1 wherein said depending hull means include generally horizontal undersurface portions.

Description:
The boat construction of the instant invention has been specifically designed to afford lateral stability as well as the ability of the boat to head into waves without excessive longitudinal pitching.

The boat includes front and rear longitudinally spaced depending displacement-type hull means and at least one of the hull means comprises a pair of laterally spaced depending hull portions. The other hull means may also comprise a pair of laterally spaced depending hull portions or a single transversely centered depending hull portion. Although the depending hull portions are of the displacement type, they may be contoured, if desired, to afford sufficient lift whereby the relatively flat bottom surfaces thereof may act as planing surfaces. Further, the depending hull means comprising a pair of laterally spaced depending hull portions includes hull portions which are slightly downwardly divergent.

The main object of this invention is to provide a boat which will afford increased lateral stability as well as the ability to head into choppy seas, swells and waves with reduced longitudinal pitching.

Another object of this invention, in accordance with the immediately preceding object, is to provide a boat construction that will be adaptable for use not only as a displacement-type hull but also as a semi-planing hull when provided with sufficient marine propulsion to propel the boat at somewhat greater speeds than that normally associated with a displacement-type hull.

A further important object of this invention is to provide a boat construction in accordance with the preceding objects including marine propulsion and steerage means that will enable efficient propulsion and control of the boat.

A final object of this invention to be specifically enumerated herein is to provide a boat construction in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and more seaworthy so as to provide a device that will be economically feasible, long lasting and safer to use.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.

FIG. 1 is a side elevational view of a first form of boat constructed in accordance with the present invention;

FIG. 2 is a bottom plan view of the boat illustrated in FIG. 1;

FIG. 3 is a front elevational view;

FIG. 4 is a front elevational view with portions of the boat being broken away and illustrated in transverse vertical section;

FIG. 5 is a view illustrating the manner in which the improved boat construction of the instant invention may ride when cresting the center of a swell with the boat in a substantially horizontal position;

FIG. 6 is a side elevational view illustrating the manner in which a conventional hull has its bow elevated when cresting a swell;

FIG. 7 is a side elevational view similar to FIG. 1 but illustrating a modified form of boat construction;

FIG. 8 is a bottom plan view of the boat construction illustrated in FIG. 7;

FIG. 9 is a front elevational view of the boat construction illustrated in FIGS. 7 and 8; and

FIG. 10 is a rear elevational view of the second form of boat construction.

Referring now more specifically to the drawings, the numeral 10 generally designates a first form of boat constructed in accordance with the present invention. The boat 10 includes an upper longitudinally continuous hull section 12 from which a cabin structure 14 is supported. In addition, the boat includes longitudinally spaced front and rear depending lower hull means 16 and 18.

From FIG. 2 of the drawings it may be seen that the depending hull means 16 and 18 each comprises transversely spaced opposite side depending hull portions 20 and 22 and that the aft depending hull means 18 also comprises a pair of laterally spaced opposite side depending hull portions 24 and 26.

The lower ends of the hull portions 20 and 22 include substantially flat horizontal bottom surfaces 28 and the lower ends of the depending hull portions 24 and 26 include similar flat surfaces 30.

Marine propulsion means in the form of horizontally inwardly offset marine screw propeller drive assemblies 32 are carried by the depending hull portions 24 and 26 and it may be seen from FIG. 2 of the drawings that the depending hull portions 20, 22, 24 and 26 are each streamlined and generally foil shaped in horizontal section so as to be capable of moving through the water with little water resistance.

The lower portion of each rear marginal portion of the hull portions 24 defines a horizontally oscillatable rudder 34 and it may be seen from FIGS. 3 and 4 of the drawings that the hull portions 20, 22, 24 and 26 are not only downwardly tapered but also slightly downwardly divergent. In addition, the bottom surface of the upper hull portion 12 disposed between the depending hull portions 20, 22, 24 and 26 is substantially flat and slightly upwardly curved at its forward end as at 36.

With attention now invited more specifically to FIG. 6 of the drawings, the circle 38 represents the center of a wave crest which is being crested by a conventional form of boat hull 40. It may be seen that in cresting the wave the bow 42 of the conventional boat hull 40 is thrust upward. However, with attention now invited to FIG. 5 of the drawings, it may be seen that the center of a wave crest 38 being crested by the boat 10 is disposed between the forward and aft depending hull means 16 and 18 so that the boat 10 remains horizontally disposed, the waterline of the hull 10 being designated at 44 in FIGS. 1 and 5.

With attention now invited more specifically to FIG. 7 of the drawings, there will be seen a modified form of boat hull construction referred to in general by the reference numeral 10' and which is similar in construction to the boat hull 10 and has its components corresponding to the various components of the boat 10 designated by corresponding prime reference numerals.

The boat 10' differs from the boat 10 in that the rear depending hull means 18 comprises a single transversely centered depending hull portion 25. The depending hull portion 25 is provided with a horizontally swingable rudder 34' and includes opposite side propulsion assemblies 32' corresponding to the propulsion assemblies 32. The center rear depending hull portion 25 tapers downwardly and is also foil-shaped in horizontal section so as to be capable of moving through the water with little water resistance. Also, the depending hull portion 25 includes a flat bottom surface 27 corresponding to the bottom surfaces 30 on the depending hull portions 24 and 26. Of course, with reference again to FIGS. 5 and 6 of the drawings, the boat 10' is capable of cresting a wave in the same manner as the boat 10 illustrated in FIG. 5.

The various depending hull portions of the boats 10 and 10' are hollow and therefore comprise displacement-type hull portions. Further, the various hull portions include forwardly and upwardly inclined bows.

If it is desired, the depending hull portion 25, as a whole, may be supported from the hull section 12' for limited oscillation about an upstanding axis concentric with a vertical drive shaft for the drive assemblies 32'. In this manner, the hull portion, as a whole, may be used as a rudder and the rudder 34' may be omitted. This may even further increase the utility of the boat 10' which has been found to drive to windward when used as a sailboat.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.