Watercraft with sound suppressed stepped hull

Abstract

A watercraft is disclosed, comprising a deck and a hull. where the hull is stepped intermediate a length of the hull to form an upper stepped surface. The upper stepped surface comprises sound suppressing dimples profiled to cancel an acoustical wave standing in the area adjacent the upper stepped surface. The watercraft has a longitudinally extending turning fin positioned adjacent to the upper stepped surface. The sound suppressing dimples are configured as inverted concave frusto-conical sections.

Description

FIELD OF THE INVENTION

The subject of the invention relates to watercraft, particularly of the type including molded and or fiberglass hulls.

BACKGROUND OF THE INVENTION

Watercraft hull design is a complicated technology as multiple objectives are trying to be met at the same time. On one hand, it is desirable for the vessel to be able to cut through choppy water and other vessels' wakes, and at the same time, it is desirable for the subject watercraft to not create a significant wake in the event that it is pulling water-skiers. It is also desirable to provide an efficiency to the hull design such that the boat easily planes over the water rather than cuts through it. For this reason stepped hulls have become popular in the vessel hull designs which provide an aerodynamic pocket under the hull helping lift the boat out of the water upon its forward propulsion.

Chines can also be used as a means of providing an air pocket along the other edges of the hull which again provide an aerodynamic lift to the vessel hull. Due to the fact that the vessel is configured for planing, the hull must also include means for stabilizing the boat and allowing for the ability to turn the boat. For this purpose a combination of strakes and turning fins are provided which can cut into the water allowing for stability and a tight turning radius. Examples of these various vessel hull designs are shown in U.S. Pat. Nos. 5,452,676; 6,666,160; and 6,923,137, all of which are incorporated herein by reference.

Given all the various surfaces provided adjacent to the waterline another phenomena has been created, that is, an acoustical chamber has been formed which can resonate noise from beneath the watercraft. That is, an acoustical chamber has been formed by a combination of the surfaces defined by the waterline, the stepped portion, the chines, and or the turning fins. While this acoustical chamber is not detrimental to the performance of the watercraft in use, it has however, increased to the point of being an annoyance to the driver and the passengers.

It is therefore an object of this embodiment to overcome the shortcomings presented.

SUMMARY OF THE INVENTION

The present embodiment is defined by a watercraft, comprising a deck and a hull, the hull being stepped intermediate a length of the hull to form an upper stepped surface. The upper stepped surface comprises sound suppressing dimples profiled to cancel an acoustical wave standing in the area adjacent the upper stepped surface.

The watercraft may further comprise a longitudinally extending turning fin positioned adjacent to the upper stepped surface. The watercraft may also further comprise a rear chine portion. The rear chine portion extends along the outer edge of the upper stepped portion. The watercraft may also comprise a forward chine portion forward of the stepped portion. The sound suppressing dimples may be configured as concave dimples. The sound suppressing dimples may be configured as inverted concave frusto-conical sections.

In a further embodiment, a watercraft comprises a deck and a hull, the hull being stepped intermediate a length of the hull to form an upper stepped surface. The upper stepped surface comprises sound suppressing means for canceling an acoustical wave standing in the area adjacent the upper stepped surface.

The sound suppressing means may be configured as concave sound suppressing dimples. The sound suppressing dimples may be configured as inverted concave frusto-conical sections. The watercraft further comprises a longitudinally extending turning fin positioned adjacent to the upper stepped surface. The watercraft may also further comprising a rear chine portion. The rear chine portion may extend along the outer edge of the upper stepped portion. The watercraft may also comprise a forward chine portion forward of the stepped portion. The sound suppressing means may be configured as concave dimples. The sound suppressing dimples may be configured as inverted concave frusto-conical sections.

In yet another embodiment, a watercraft comprises a deck and a hull, the hull having a plurality of surfaces forming an acoustical chamber with the waterline. The hull comprises sound suppressing dimples profiled to cancel an acoustical wave standing in the chamber.

The sound suppressing dimples may be configured as inverted concave frusto-conical sections. The watercraft may also further comprise a longitudinally extending turning fin positioned adjacent to the acoustical chamber. The hull may be stepped intermediate a length of the hull to form an upper stepped surface, where the upper stepped surface comprises the sound suppressing dimples. The watercraft may also further comprise a longitudinally extending turning fin positioned adjacent to the upper stepped surface. The watercraft may also further comprise a rear chine portion. The rear chine portion extends along the outer edge of the upper stepped portion. The watercraft may also comprise a forward chine portion, forward of said stepped portion. The sound suppressing means may be configured as concave dimples. The sound suppressing dimples may be configured as inverted concave frusto-conical sections.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a typical watercraft shown from the starboard side;

FIG. 2 is an underside view of the hull of the present embodiment;

FIG. 3 is a perspective view from the port side of the watercraft of FIG. 1;

FIG. 4 is an end view from the aft end of the boat of the present embodiment;

FIG. 5 is an end view from the bow of the watercraft of the present invention;

FIG. 6 is an underside perspective of the watercraft hull of the present invention taken from the starboard side;

FIG. 7 is a view similar to that of FIG. 6 showing the hull inverted;

FIG. 8 is an enlarged view of the encircled portion shown in FIG. 7;

FIG. 9 is a view similar to that of FIG. 8 taken from a different perspective;

FIG. 10 is a view showing the sounds suppression panel of the present embodiment;

FIG. 11 is a cross sectional view through the sound suppression panel, at the position 11-11 of FIG. 10, with the watercraft shown in the water; and

FIG. 12 shows an enlarged view of the encircled portion shown in FIG. 11.

BRIEF DESCRIPTION OF THE EMBODIMENT OR DETAILED DESCRIPTION OF THE EMBODIMENT

With reference first to FIGS. 1 through 5, the general details of the watercraft will be described herein. With reference first to FIG. 1, the watercraft is shown generally at 2 and includes a deck portion 4 attached to a vessel hull 6. It should be understood that these two units are typically constructed in separate halves and then joined together along a central seam. It should also be noted that these decks and hulls are typically molded, or made from fiberglass about a mold, however the actual construction is not material to the invention. The watercraft 2 further includes an aft portion 8 and a bow portion 10, and as shown in FIG. 3 includes a port side 12 and a starboard side 14.

With reference now to FIGS. 2, 4 and 5, the vessel hull 6 further comprises a V shaped bottom portion 16, and port side and starboard side chines 18 which includes a forward chine surface 20 (FIG. 5) and a rearward chine surface 22 (FIG. 22). Primary strake portions 24 also flank secondary strake portions 26, as best shown in FIGS. 2 and 5.

With reference now to FIGS. 6, 7 and 8, a stepped portion 30 is defined which defines a stepped wall 32 (FIG. 8) thereby defining surface 34 of hull 6 and an upper stepped surface 36. This also defines an inner sidewall at 38. The stepped portion 30 extends through chine 18 defining surface 39 which opens up on the side of the hull 6. A turning fin 40 is also provided and is positioned on the rear chine surface 22. Turning fin 40 includes a curved surface at 42 and an inner surface at 44. As best shown in FIG. 9, an opening 50 is defined between the stepped wall portions 32, 39 and turning fin 40 is shown best in FIGS. 8 and 9.

With reference now to FIGS. 8-10, the area of surface 36 bounded by stepped wall portion 32, 39; wall 38 and inner surface 44 of turning fin 40 is provided with a sound suppression surface as shown generally at 60. As shown best in FIG. 10, sound suppression device 60 is applied to surface 36, with a contoured surface 62, profiled to reside in close proximity to edge 32, a portion 64 which resides in opening 50, a curved surface 66 which tucks behind turning fin 40 and a plurality of openings 68. In this embodiment, the suppression surface is integrally molded into the hull, although it could be a separate panel, adhesively fixed onto the hull. With reference now to FIGS. 10-12, the operation of the sound suppression device will now be described.

With reference to FIG. 11, a cross sectional view is shown at a point when the watercraft 2 is planing. Surface 36 is shown raised above waterline WL, and the combination of the surfaces 36, 22, 44 and 32 (FIG. 10) forms an acoustical chamber 90 beneath the watercraft. As shown in FIG. 12, sound suppression apertures 68 are shaped frusto-conically to include inner conically shaped walls 70 with end walls 72. Rather, as shown, panel 60 is provided along surface 36, for the majority of the length that surface 36 is positioned above the water line WL. Thus sound waves that reflect off of panel 60 are cancelled. Some of the sound waves SW₁ reflect off of one portion of frusto-conical portions 70 defining a reflected sound wave RW₁ while other sound waves SW₂ reflect off of other side of frusto-conical portions 70 defining a reflected sound wave RW₂. It should be appreciated that reflected waves RW₁ and RW₂ cancel each other out, deadening the sound.

In the embodiment shown, the sound suppression apertures are provided with diameters at the surface of approximately ⅛ to ¼ inch in diameter. It should be apparent that other geometries could be applied to achieve the same sound suppressing results. It should also be appreciated that the number (or density) of the apertures and/or their geometry can be modified depending upon the frequency of the sound to be suppressed.

Claims

1. A watercraft, comprising a deck and a hull, the hull being stepped intermediate a length of the hull to form an upper stepped surface, said upper stepped surface comprising sound suppressing dimples profiled to cancel an acoustical wave standing in the area adjacent the upper stepped surface.

2. The watercraft of claim 1, further comprising a longitudinally extending turning fin positioned adjacent to the upper stepped surface.

3. The watercraft of claim 2, further comprising a rear chine portion.

4. The watercraft of claim 3, wherein the rear chine portion extends along the outer edge of the upper stepped portion.

5. The watercraft of claim 4, comprising a forward chine portion forward of said stepped portion.

6. The watercraft of claim 5, wherein the sound suppressing dimples are configured as concave dimples.

7. The watercraft of claim 6, wherein the sound suppressing dimples are configured as inverted concave frusto-conical sections.

8. The watercraft of claim 1, wherein the sound suppressing dimples are configured as inverted concave frusto-conical sections.

9. A watercraft comprising a deck and a hull, the hull being stepped intermediate a length of the hull to form an upper stepped surface, said upper stepped surface comprising sound suppressing means for canceling an acoustical wave standing in the area adjacent the upper stepped surface.

10. The watercraft of claim 9, wherein the sound suppressing means are configured as concave sound suppressing dimples.

11. The watercraft of claim 10, wherein the sound suppressing dimples are configured as inverted concave frusto-conical sections.

12. The watercraft of claim 9, further comprising a longitudinally extending turning fin positioned adjacent to the upper stepped surface.

13. The watercraft of claim 9, further comprising a rear chine portion.

14. The watercraft of claim 13, wherein the rear chine portion extends along the outer edge of the upper stepped portion.

15. The watercraft of claim 14, comprising a forward chine portion forward of said stepped portion.

16. The watercraft of claim 15, wherein the sound suppressing means are configured as concave dimples.

17. The watercraft of claim 16, wherein the sound suppressing dimples are configured as inverted concave frusto-conical sections.

18. A watercraft, comprising a deck and a hull, the hull having a plurality of surfaces forming an acoustical chamber with the waterline, the hull comprising sound suppressing dimples profiled to cancel an acoustical wave standing in the chamber.

19. The watercraft of claim 18, wherein the sound suppressing dimples are configured as inverted concave frusto-conical sections.

20. The watercraft of claim 18, further comprising a longitudinally extending turning fin positioned adjacent to said acoustical chamber.

21. The watercraft of claim 18, wherein the hull is stepped intermediate a length of the hull to form an upper stepped surface, said upper stepped surface comprising said sound suppressing dimples.

22. The watercraft of claim 21, further comprising a longitudinally extending turning fin positioned adjacent to the upper stepped surface.

23. The watercraft of claim 22, further comprising a rear chine portion.

24. The watercraft of claim 23, wherein the rear chine portion extends along the outer edge of the upper stepped portion.

25. The watercraft of claim 24, comprising a forward chine portion forward of said stepped portion.

26. The watercraft of claim 25, wherein the sound suppressing means are configured as concave dimples.

27. The watercraft of claim 26, wherein the sound suppressing dimples are configured as inverted concave frusto-conical sections.