SYSTEM FOR ATTITUDE CONTROL AND STABILIZATION OF A MARINE CRAFT

Abstract

A system for attitude control and stabilization of a marine craft includes at least one elongate substantially planar surface, which may be rigid or flexible, disposed on either side of and in substantial alignment with a bottom of the planing hull of the marine craft. The elongate surface, in a rigid form, includes a tongue-like distal end confined within a fluid hinge enclosure upon a region of the hull about 2 to 8 feet forward of the transom. In a flexible form, a distal end of the elongate planar surface is secured directly to the hull. The elongate surface further includes an actuation portion proximal to a transom of the craft. The system also includes an actuator selectably slidable and securable within an actuation sleeve, the sleeve secured to the transom of the craft. Also included in the system are elements, manual, hydraulic or electrical, for selectably advancing the actuator relative to the hull to induce a selectable angulation of the elongate planar surface relative the bottom of the hull of the craft.

Description

FIELD OF THE INVENTION

The present invention relates to an improvement in classical trim-tab technology to enhance the general hydrodynamic performance of a marine craft inclusive of the fuel efficiency thereof.

BACKGROUND OF THE INVENTION

So-called boat leveling devices of the trim-tab type have been known for many years and various forms of them have been developed in an effort to maximize attitude control, stability of the marine craft and general hydrodynamic efficiency inclusive of decrease of flow velocity under the hull and fuel efficiency.

The prior art trim-tabs which typically are provided in pairs to enhance stability of the craft, is shown in FIGS. 1 and 2 herewith. More particularly, FIG. 1 shows a traditional external trim-tab 2 of which is attached directly to transom 3 of a craft 100 and in which the attitude of the trim-tab is controlled through a hydraulic piston assembly 4 which controls relative angulation of the hull relative to level of the water. Also shown in FIG. 1 is a servo-loop wiring 9 by which assembly 4 are controlled.

The prior art shown in FIG. 2 differs from that of FIG. 1 only in that the trim tab 2 is positioned beneath stern 6 of the craft 100 and forward of propeller 8. Therein, the direction of assembly 4 and hydraulic piston 5 are aligned with the gravity vector as opposed to the angled position of the hydraulic assembly shown in the prior art of FIG. 1.

In general trim-tabs of the prior art, whether double or single acting, will operate upon the same principles and have a common objective, namely, that of contributing to the efficiency control of the boat's attitude, stabilization and general hydrodynamics.

In recent years, most efforts of the prior art have been directed primary to improvement of the electronics and the development of algorithms to optimize trim-tab control under various conditions of vehicle speed, wave conditions, shape of the boat's hull, having distribution in craft, and other hydrodynamic considerations. The prior art also has experimented with the efficiency of electric motor controls of the trim tabs as opposed to that of the hydraulic systems shown in FIGS. 1 and 2. In general, the durability of electric motor controls has proven to be superior than that of hydraulic actuators.

The U.S. Navy has undertaken significant research and development in this area to attempt to maximize performance of a variety of its boats and, typically, of the types employed by the U.S. Coast Guard. In Navy terminology, a trim-tab is referred to as a stern flap, apparently because its engineering objectives are more ambitious than are the case with a leisure class powerboat. More particularly, the Navy has identified the following criteria as hydrodynamic mechanisms which account for improved boat performance based on optimized stern flap design.

After body flow modifications:

• • Flow velocity under the hull decreased.
  • Pressure recovery increased.
  • Transom exit velocity increased.

Wave system modifications:

• • Localized transom system wave system altered.
  • Near field wave heights reduced.
  • Far field wave energy reduced.

Secondary stern flap hydrodynamic effects:

• • Ship length increased.
  • Beneficial propulsion interactions.
  • Ship trim modified (bow down trim induced).
  • Ship sinkage is reduced.
  • Lift and drag forces developed on flap.

The within inventor has recognized that the fundamental objectives and benefits of trim tabs and stern flaps may be more effectively achieved if the entire length of the trim-tabs or stern flaps are extended. And that, when properly actuated and controlled, such elongated attitude control element, as suggested can accomplish and substantially improve upon the performance of prior art trim tabs and stern flaps regardless of hydrodynamic conditions. The efficiency of the present invention may be yet further improved the assistance of contemporary electronic controls and algorithms. The present invention also improves upon efforts that seek to improve the performance of trim tabs thereof through modification of their geometry as, for example, is reflected in U.S. Design patent No. 292,392 (1987) to Zepp, entitled Boat Leveler Twin Tab.

SUMMARY OF THE INVENTION

The instant invention relates to a system for attitude control, inclusive of stabilization of a marine craft. The system includes at least one elongate substantially planar surface disposed on either side of and in substantial alignment with or parallel to a bottom of the planing hull of the craft. In a rigid embodiment, said elongate surface includes a tongue-like distal end confined within a fluid hinge enclosure upon a region of the hull at about 2 to 8 feet forward from the transom. In a flexible embodiment, the distal end of said elongate surface is secured directly to the hull. The system further includes an actuator proximal to a transom of the craft, in which the actuator urges against the elongate planar surface downwardly relative to the plane of hull. The actuator is selectably slidable and securable within an actuation sleeve, the sleeve secured to the transom of the craft. Further included in the system are means, either manual, hydraulic or electrical, for selectably positioning the actuator relative to the sleeve to induce a selectable angulation of a proximal portion of the elongated planar surface to thereby adjust the plane of said elongate planar surface relative to a plane defined by the bow-to-stern of the craft.

It is accordingly an object of the present invention to provide an improved trim tab system which overcomes the various hydrodynamic limitations of the prior art, the same having utility with leisure as well as naval vessels.

It is another object of the invention to provide a trim tab system capable of inducing a greater change in bow-to-stern or glide angle angulation of the marine craft relative to the water level while increasing the fuel efficiency thereof.

It is a yet further object to provide a system of the above type which furnishes improved accuracy of adjustment versus prior art trim tab stern flap systems.

It is a further object to provide a system of the above type having utility in improved performance of marine craft whether used in a single or double trim tab context.

It is a still further object to provide a system to improve the degree and control of the glide angle of the watercraft and its ability to correct uplift zones to facilitate a more favorable weight distribution, each resulting in reduced fuel costs.

The present invention also seeks to reduce the need for submersible flow interceptors as they are know in the art.

The present invention therefore seeks to provide more effective trimming coupled with the greatest possible uplift and lowest water resistance values, both at slow and high speeds, in a manner that does not substantially complicate the kinematics of prior art attitude control systems.

The above and yet other objects and advantages of the present invention will become apparent from the hereinafter set forth Brief Description of the Drawings, Detailed Description of the Invention and Claims appended herewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of one form of prior art trim tab system

FIG. 2 is a schematic view of a second form of prior art trim tab system.

FIG. 3 is a schematic side elevational view showing one embodiment of my system including its glide angle adjustment capability.

FIG. 4 is a stern end view of the illustration of FIG. 3.

FIG. 5 is a perspective schematic partial exploded view of the present system installed upon the hull and transom of a marine craft.

FIG. 6 is a view, generally similar to that of FIG. 3, however showing the flexible tab embodiment of my system.

FIG. 7 is a view generally similar to that of FIG. 6 showing an extension of the actuator.

FIG. 8 is a top perspective view of the system of FIGS. 6 and 7.

FIG. 9 is a perspective view of the system of FIGS. 3 and 4.

FIG. 10 is an exploded view of the system of FIGS. 3, 4, and 9.

FIG. 11 is a perspective view showing a third embodiment in which a power actuator is used with a flexible tab element.

FIG. 12 is a view generally similar to FIG. 11 but showing a manual actuator in combination with a power actuator and a flexible tab.

FIG. 13 is a view generally similar to FIG. 12 but showing the system thereof with a rigid tab.

FIG. 14 is a perspective view of a power actuator used with a manual actuator, both with a rigid tab.

FIG. 15 is a perspective view showing or a manual actuator disposed between power actuators.

FIG. 16 is an exploded view showing two separate types of fluid hinge assemblies.

FIG. 17 is a side plan view of the embodiment of FIGS. 3, 4 and 10.

FIG. 18 is a sequential view showing the operation of the actuation of the tab of the system of FIG. 17.

FIG. 19 is an enlarged view of the fluid hinge portion of FIG. 17.

FIG. 20 is a perspective view of the bottom of the fluid hinge assembly.

FIG. 21 is a rear elevational view of the first embodiment of the actuator of my system when installed upon a transom of a marine craft.

FIG. 22 is a rear elevational view of the planning surface and fluid hinge receiver of my system installed upon the stern area of the hull of a boat.

FIG. 23 is a perspective view of the power actuator of FIGS. 11 and 12, however showing a fixed pivot proximal end connection to a flexible tab.

FIG. 24 is a view, similar to that of FIG. 23, but showing another form of securement of the power actuator to the transom.

FIG. 25 is a lower perspective view of the manual actuator of FIGS. 3-5 including a flexible tab having sidewalls and clip connectors at the distal end of the tab.

FIG. 26 is a vertical cross-sectional view of FIG. 25 showing the manner of engagement of the clip connectors with complemental elements depending from the bottom of the hull of the boat.

FIG. 27 is an enlarged view of the circled portion of FIG. 26.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the schematic views of FIGS. 3-4, the stern and mid-hull elements of a first embodiment the invention are shown. More particularly, a craft may be seen to include a hull 20 and transom 3 to which is secured a vertical plate 22 which extends downward and behind an actuation sleeve 30. Within actuation sleeve 30 is actuator 28 which urges downwardly against an elongate planar attitude control surface, also referred to herein as tab 26. It may be seen in FIGS. 3, 5, 9 and 10. The attitude control surface may be either rigid or flexible, the flexible surface indicated as element 126, in FIGS. 6-8 and 10-11.

In the manually operated embodiment of the present system, handle 29 is employed to advance actuator 28 downward to a desired aperture 46 at which a transverse bar portion of the handle is employed to establish a fixed location tab 26 below the keel of the boat. Typically, said surface is adjustable in a range of about zero to at least 15 degrees relative to the keel of the boat, this is may be seen in FIGS. 3, 6 and 8. The structure of FIG. 4 may be seen in exploded view in FIG. 10. The tab or elongate planar attitude central surface 26 more particularly includes a distal tongue element 39 which is held by a fluid hinge receiver 41 which is secured at a distal area to keel 20 of the boat. Thereby, as for example is shown in FIGS. 7-8 and 17-19, said elongate surface 26 is held to the hull 20 by rivets 134 to assure stability of the receiver 41.

In a preferred embodiment, said tabs 26 are provided with downwardly directed sidewalls 40 (see FIGS. 9-10) which operate to enhance the stability of the present attitude control system. Said embodiment may, in certain applications, define a length of about 30 inches but, in other embodiments (see for example FIG. 11), may be much shorter. An elongate and flexible portion 126 of intermediate length is shown in the embodiment of FIG. 12. As may be noted, sidewalls 40 are not required in the flexible tab embodiment.

In accordance with the present invention, there are taught two basic embodiments of elongate planar attitude central surface 26, namely, the rigid embodiment as is shown in FIGS. 3, 5, 9, 10, and 13-16, and the flexible embodiment which is shown in FIGS. 6, 8, 11 and 12. It is to be appreciated that in both elongate embodiments, the proximal portion 125 may operate with any combination of types of actuators, as is more fully described below.

With reference to FIG. 6, it is to be appreciated that in the flexible tab embodiment a distal end of planar structure 132 may be inlayed directly into the hull 20 of the boat, in which case a securing plate 134, held by bolts 133 or the like, is employed.

FIG. 6 also shows the manner in which vertical actuator sleeve 30 may be secured to transom 13.

In the present invention, the curvature of distal end 128 of actuator 28 plays an important role in the functioning of the attitude control surface 126, particularly in the flexible plate embodiment of the invention. More particularly, as may be seen in FIGS. 6, 7, 8, and 10, the surface at end 128 is rounded to facilitate ease of contact with surface 126 with a minimum of friction against distal end 128 and upon said surface 126.

Further, actuator 28 may freely engage proximal portion 125 or, as is shown FIGS. 4, 5, and 8-10, may be secured to said surface of the attitude control member by brackets 25 which are held to the distal end 128 of the actuator 28 by axle 36. See FIG. 8.

The present system also contemplates the selectable use of power actuators 130 (see FIGS. 11-15) which may be employed either separately or in combination with manual actuators as set forth above and shown in FIGS. 3-10. In many applications as, for example, is shown in FIGS. 12-15, it is useful to employ one or more power actuators in combination with a manual actuator. Therein, a single manual actuator is placed between two power actuators, that is, may be placed at either side of a manual actuator and held by plate 122, as is shown in FIGS. 13 and 15. FIGS. 12 and 14 illustrate use of a power actuator 130 secured in front of a manual actuator 28 in respective flexible and fixed tab embodiments of the invention. More particularly, in FIG. 14 is shown power actuator 130, having extensible element 138. secured to manual actuator 28 by a metal band 129 which attaches to transom plate 22. Both actuators rest upon plate 125.

As may be appreciated, each power actuator, regardless of how employed, includes said extensible element 138 at an end of the power actuator 130 which uses internal means for power extension that may be either hydraulic or electrical. This strategy may be seen with reference to the embodiments of FIGS. 12 and 13. Therein, if one wishes not to use the manual actuator, handle 31 thereof may simply be placed in a topmost position as for example is shown in FIGS. 12-15. Therein, the weight of gravity will assist power actuator 130 in its downward urging of proximal portion 26 of elongate attitude control surface 24.

Where two power actuators 130 and 130A are employed, one may employ brackets 125 secured to distal end 128 of the manual actuator to equalize the effect of possibly unequal extensions between elements 138 of each power actuator that otherwise might cause an imbalance upon the proximal portion 26 of elongate attitude control surface 24. See FIG. 15.

FIG. 16 is an exploded view of two embodiments of the receiver of the present invention in which clip tabs 42 may be attached at the distal end 39 of attitude control surface 24. Alternatively, lateral elements 142 of receiver 41 may be secured to hull of the boat in the manner shown in FIGS. 17 to 19 in which provide a more detailed view of the embodiment of FIGS. 3-5 in which the downward rotation of rigid attitude control surface 24 may be seen and, therewith, the extension of the actuator downwardly against proximal portion 26 of elongate planar surface 24. Therein may be seen the manner in which vertical distal surface 47 of elongate surface 24 facilitates insertion of its tongue element 39 into fluid hinge receiver 41 which in turn is secured to hull 20 of the boat. In other words, an hinge effect is accomplished by the structure shown in FIG. 18 while proximal end 26 of elongate planar element 24 is able to rotate downwardly with the distal end of actuator 28 upon axle 36 to a depth in a range of about four to ten inches and to an angle of up to at least 15 degrees. An enlarged view of the hinge area of FIG. 18 is shown in FIG. 19.

In FIG. 20 is shown a bottom perspective view of fluid receiver 41 shown in FIGS. 5, 8 10 and 15-19

In FIG. 21 is illustrated the attachment of a manual embodiment of the present system, with one unit attached at opposite sides of keel 7 of the marine craft across the transom 13 thereof.

In FIG. 22 is shown the location of receivers 41 which may be secured to bow 15 of the marine craft by elements 150.

It is to be further appreciated that the actuator assembly, as above described, may be positioned and secured internally to the hull in the manner shown in FIG. 2 or lower within the hull. Therein, the actuator is extensible beyond the keel of the boat to the proximal portion of the elongate planar surface 26.

FIG. 23 is a view of the power actuator 130 of FIGS. 11 and 12 in which proximal end 138 thereof is rotatably secured by axle 136 within brackets 125 of forward end 124 of flexible tab 132A. Also shown is transom plate 122, extension plates 132 and 134 of actuator 130 and axle 132 therebetween. A metallic strip 129 holds actuator 130 to transom plate 122.

FIG. 24 is a view, generally similar to that of FIG. 23, in which there are provided protective housings 222 and 222A which include axle 229 therebetween upon which distal element 224, depending from power actuator 130 may rotate while securing a distal end of the actuator 130. Also, in FIG. 23, proximal end 138 of the actuator is rotatably secured to forward end 124 of flexible tab 132A by brackets 125 and an axle 236 between said brackets.

FIG. 25 is a lower perspective view showing a manual actuator 28 of the type of FIGS. 3-5 including guide and sidewalls 40 depending from forward end 26 of tab 232A. However, unlike the embodiment of FIGS. 3-5, tongue and receiver elements 39/40 thereof, are replaced by quick connect prongs 242, depending from tab 232A, which are held by complemental female elements 241 within the hull. See FIG. 26. Also shown in FIG. 25 is actuator guide assembly 22.

FIG. 26 is a vertical cross-sectional view of the embodiment of FIG. 25, showing the manner in which prongs 239 engage female elements 241 of tab 232A. Proper positioning and securement of prongs 239 is assured by the prong 239 depending from bolts 243 which are secured to hull 20 by plates 245 and 246 and associated lock nuts 247. This arrangement is shown in enlarged view in FIG. 27. Therein a full range of motion of tab 261/232A relative to hull 20 may be achieved as is shown to the right of FIG. 26. The actuator guide 22 is secured to transom 13 by actuator plate 22A. Also shown therein is actuator 28 and lower brackets 225 to which tab 26/232A is rotatably secured as discussed above regarding FIG. 18.

While there has been shown and described above the preferred embodiment of the instant invention it is to be appreciated that the invention may be embodied otherwise than is herein specifically shown and described and that, within said embodiment, certain changes may be made in the form and arrangement of the parts without departing from the underlying ideas or principles of this invention as set forth in the Claims appended herewith.

Claims

1. A system for attitude control and stabilizing of a marine craft, the system comprising:

(a) at least one elongate substantially planar surface disposed substantially in parallel with a bow-to-stern axis of one side of a bottom of a hull of the marine craft, said elongate planar surface further including a proximal actuatable portion at a stern end of said planar surface, said proximal portion extending from beneath said hull to beyond a transom of the craft;

(b) an actuator slidably positionable within a substantially vertical containment sleeve, said sleeve secured to a transom of said marine craft, a lower end of said actuator in selectable contact with said proximal portion of said elongate planar surface;

(c) means for selectably advancing said actuator within said sleeve against said proximal portion of said planar surface to define a planing angle of said elongate planar surface relative to said one side of said hull of the marine craft to which it is secured; and

(d) distal end of said elongate planar surface defines a tongue-like geometry confined within a fluid hinge defining enclosure secured upon said hull of the craft.

2. The system as recited in claim 1, in which a range of adjustment of said elongate planar surface relative to the axis of the bottom of the hull of the marine craft is in a range of about zero to at least 15 degrees.

3. The system as recited in claim 1, further comprising a stop limit to preclude over extension of said actuator relative to said actuation sleeve.

4. (canceled)

5. The system as recited in claim 1, in which a transverse cross-section of said actuator and sleeve each define a square or rectangle.

6. The system as recited in claim 1, in which a traverse cross-section of said actuator and sleeve each define a circle.

7. The system as recited in claim 9, said elongate planar surface comprises:

downwardly directed integral side edge elements substantially along an entire length of said elongate planar surface.

8. The system as recited in claim 3, in which a transverse cross-sectional of said elongate planar surface defines an inverted letter “U” at the proximal region of said elongate surface.

9. The system as recited in claim 1, in which said elongate planar surface comprises a rigid material.

10. The system as recited in claim 1, in which said elongate planer surface comprises a flexible material, a distal end of said surface rigidly secured to said hull of the vessel.

11. The system as recited in claim 1, in which said actuator comprises a power actuator.

12. The system as recited in claim 1, in which said actuator comprises one or more manual and hydraulic actuators mounted together with each other.

13. (canceled)

14. The system as recited in claim 1, in which said fluid hinge defining enclosure defines a location of between about 2 feet and about 8 feet forward of the transom.

15. The system as recited in claim 3, in which said distal end of said elongate planar surface includes male elements proportioned for complemental engagement of female elements depending from an opposing surface of the hull of the marine craft.

16. The system as recited in claim 8, in which said distal end of said elongate planar surface includes male elements proportioned for complemental engagement of female elements depending from an opposing surface of the hull of the marine craft.