GB2055080A - Propelling watercraft - Google Patents

Abstract

A watercraft has at least one cylindrical hull (1), at least one duct (2) extending longitudinally within the hull (1) and, at the bow inlet of the duct (2) a propeller (10) for propelling said watercraft. <IMAGE>

Description

SPECIFICATION Front-propulsion watercraft The present invention relates to a front-propulsion watercraft.

As it is known, the watercrafts, of any size, generate, during the sailing, a wake which, generally, depends on the type of watercraft, and on the type of motor associated to said watercraft.

It is also known that the more the wake is "clean" the better is the trim of the watercraft.

The presence of a waving motion, as generated by the wake, causes drawbacks of different types.

Firstly, an excessively waving wake inevitably deteriorates the navigation trim for a badly designed hull.

Furthermore, the waving motion of the wake causes a loss of the driving power of the watercraft, since the power transmitted to the waves is provided by the engine, being however hardly exploited by the watercraft itself.

Other drawbacks are directly related to the waving motion of the wake.

In fact, in narrow docks or lagoons, the waving motion, as determined by the watercraft wakes, causes an appreciable increase of the wear and damagings to the basin or channel bank sides.

Accordingly, the task of the present invention is to obviate the thereinabove mentioned drawbacks by providing a front-propulsion or propelled watercraft of new design, able of sailing in a "smooth" way, that is without causing a waving motion in the wake thereof and, consequently, able of providing a great reduction in the fuel and motion or driving power in general consumption.

Within this task, it is a specific object of the present invention to provide such a watercraft the structure whereof is very simple and able of easily fitting to the construction or making of any watercrafts, depending, obviously, on the specific provided use of said watercraft.

Another object of the present invention is to provide such a watercraft which, in addition to afford a sailing of more safety, is able of completely obviating any dangers to the persons.

In fact, in the instant watercraft, are completely absent any rotating elements accessible from the outside, contrarily to the propellers of the in-board and off-board engines as presently used.

Yet another object of the present invention is to provide such a watercraft which is of very reduced maintenance and which, in addition, is extremely competitive from a merely economic point of view.

The task and objects thereinabove cited and yet other objects which will become more apparent thereinafter, are achieved by a frontpropulsion watercraft, according to the invention, characterized in that it comprises a hull, formed by at least a cylinder, extending longitudinally, in the inside whereof at least an inner cylinder is provided effective to define, cooperatively with said first cylinder, a tightly closed gap, determining the capacity of said watercraft.

At the bow inlet of said first inner cylinder there is provided a propeller for propelling the watercraft, affective to accelerate the water flow to the inner cylinder, in order to obtain a jet drive.

Further characteristics and advantages of the invention will become more apparent from the following detailed description of a preferred though not exclusive embodiment of a front-propulsion watercraft, being illustrated, as an indicative but not limitative example, in the accompanying drawing, where: Figure 1 is a schematic view illustrating a possible embodiment of a watercraft, as seen by a side elevation and partly broken away longitudinal view; Figure 2 is a schematic view of a watercraft as seen from the bow.

Referring specifically to the figures, the front-propulsion watercraft according to the present invention is characterized in that it comprises a hull being formed by at least a longitudinally extending cylinder.

In the accompanying drawings there is illustrated a watercraft which could be defined as a catamaran type of watercraft, being formed by associating two cylinders (1), being spaced from one another and extending parallely.

Within each said cylinder (1), there are provided one or more inner cylinders, of less diameter, indicated at (2), which extend parallely to the axis of the cylinder (1) and practically all along the length of the outside cylinder (1).

The cylinder (1), and the inner or inside cylinder or cylinders (2), define therebetween a gap, indicated in the drawing at (3).

This latter is tightly closed and, practically, determines the capacity of the hull, since it provides a suitable bouyancy zone.

Advantageously, at the bow inlet, the inner cylinder (2) connects to the front end of the outside cylinder (1), by a mouth or inlet (4) of substantially frustum conic shape.

Likewise, at the stern, there is provided a flaring (5), connecting the inner cylinder (2) to the outside cylinder (1).

Advantageously the inside cylinder (2) is eccentrically located with respect to the outside cylinder (1 ) and, more specifically, the eccentricity thereof is downwards directed.

The number as well as the diameter of the inner cylinder, are designed proportionately to the speed to be obtained for the watercraft, and depending on the specific provided use for the watercraft.

At the bow, and more precisely at the inlet (4), frontwardly from each inner cylinder (2), there is provided a propeller (10) which, in the example illustrated in the drawing, is rotated by means of a chain drive (11), by a central engine (12) driving both said propellers.

Obviously it is possible to provide, for each propeller, a respective driving engine, which may be of a conventional outboard type, or, possibly an outboard-inboard type of engine or motor.

The basic- concept of the invention is that it provides for the use of a propeller which is located at the front portion of the hull, and not at the rear portion thereof, as conventional.

The propeller, during the rotating movement thereof, carries out a propelling motion, which is also effective to accelerate the fluid flow, to the inside of the inner cylinders (2), thereby providing, substantially, a jet type of drive.

It should be noted that, by channeling the fluid flow to the inside of the inner cylinder (2), the swirlings caused by the propeller are eliminated since the fluid flow, by moving through a suitable length in the inside of the cylinders, exits therefrom with fluid threads substantially mutually parallel and all pointing to the propelling direction.

This characteristic, in addition to considerably increase the hull efficiency, the dispersive motions being absent, creates a very smooth and clean wake, practically devoid of any motions susceptible to cause the drawbacks thereinabove described.

The outside cylinder (1), which practically provides the buoyancy portion of the hull during a normal sailing, is submerged in the water and supports a structure, indicated schematically at (2), for the use load of the watercraft.

At the stern, as it is conventional, there is located the steering compartment, the drive whereof is not herein specifically described, since it is of a known type.

From the above description it should be noted that the invention fully achieves the intended objects.

More specifically it is pointed out the fact that the solution of channelling the fluid propelling flow to the inside of the inner cylinder (1), allow for, at first, a jet type of drive to be obtained for the watercraft and, furthermore, it permits to convey the fluid thread, thereby preventing swirlings from occurring so as to obtain a very high efficiency.

The invention, as described, is susceptible to several modifications and variations, all falling within the inventive concept scope.

Thus, for example, in the case of high speed watercrafts, it is possible to locate the outlet of the fluid along the cylinders, instead that at the stern, thereby improving the capac ify or "static lift" of the hull, and its stability during the sailing.

Furthermore all of the making details, such as the motor type, as well as the structure located above the cylinders, and the shape of these latter, are susceptible to many variations, without departing from the inventive concept.

In practicing the invention, the used mated: als, provided that they are compatible with the specific intended use, and the contingent size and shape may be any, according to the needs.

Claims (11)

1. Front propulsion watercraft, characterized in that it comprises a hull, formed by at least a cylinder, extending longitudinally, in the inside whereof at least an inner cylinder is provided, effective to define, cooperatively with said first cylinder, a tightly closed gap, determining the capacity of said watercraft, at the bow inlet of said inner cylinder there being provided a propeller for propelling said watercraft, effective to accelerate the water flow to said inner cylinder, in order to provide a jet drive.

2. A front propulsion watercraft, according to the preceding claim, characterized in that said inside or inner cylinder is connected to the other cylinder, at the bow, by a substantially frustum conic inlet, and, at the stern, by a substantially frustum conic flaring.

3. A front propulsion watercraft, according to one or more of the preceding claims, characterized in that said inner cylinder is located eccentrically in said second cylinder, the eccentricity being towards the bottom.

4. A front propulsion watercraft, according to one or more of the preceding claims, characterized in that it comprises a pair of cylinders, extending parallely to one another and adjoining one another, within each said cylinder there being provided at least an inner cylinder.

5. A front propulsion watercraft, according to one or more of the. preceding claims, characterized in that itXcomprises a propeller for each said inner cylinders.

6. A front propulsion watercraft, according to one or more of the preceding claims, characterized in that said propellers, as located at each said inner cylinder, are driven by a single engine by means of chain drives.

7. A front propulsion watercraft, according to one or more of the preceding claims, characterized in that each said propeller is driven by a respective engine.

8. A front propulsion watercraft, according to one or more of the preceding claims, characterized in that said cylinder, during the sealing, is submerged and supports a structure, of any shape, for the use load of said watercraft.

9. A front propulsion watercraft, according to the preceding claims, characterized in that the water flow, as channeled into said inside cylinders, is effective to eliminate the swirlings in said cylinders, thereby providing a plurality of fluid threads, as parallely extending to one another.

10. A front propulsion watercraft, according to the preceding claims, characterized in that the engine of said watercraft can be located at any place.

11. A front propulsion watercraft, characterized in that said cylinders, that is the inner one and the outside one, are susceptible to have any suitable contours and shapes.

1 2. A front propulsion watercraft, according to the preceding claims, and as broadly described and illustrated for the intended objects.

1 3. A front propulsion watercraft substantially as herein described with reference to and as illustrated in the accompanying drawings.