FIELD OF THE INVENTION

The object of the invention is an arrangement, as defined in the preamble of claim 1, in a boat and a support structure, as defined in the preamble of claim 13, to be used in the arrangement.

BACKGROUND OF THE INVENTION

When a boat travels in water, the hull of the boat encounters braking forces as well as irregular tilting forces produced by waves. Various methods have been tried to reduce these braking forces, and the forces causing instability, including e.g. a variety of lifting strakes, chines, trim tabs, and hydrofoils, hereinafter also referred to more briefly as flow guides, that direct the flow of the water. Their purpose is to change the attitude of the boat in motion and to get the vessel to behave in a more stable and more energy-efficient manner.

The purpose of flow guides is to direct the flow of water and to thereby form a force acting in the manner desired on the travel of the boat. Their task is to change the attitude of the vessel in the water and to at least partly lift the hull out of the water. In this way the boat is made to rise into planing mode at a lower speed, reducing the wave formation of the hull and also the friction between the water and the hull. Fuel consumption is reduced by reducing wave formation and by reducing friction. By changing the angle of the hull with respect to the water, the characteristics of the boat in different conditions, e.g. for different loads, can be changed.

Currently used in prior art are lifting strakes installed on the bottom side of the boat or a straked bottom integrated into the lower hull of the boat. A straked bottom is used in racing boats and many factory-produced boats reduce friction. Trim tabs are used on larger boats. Trim tabs and wings, lifting strakes and guides that are in contact with the water, as well as other corresponding solutions, increase the contact surface with the water and therefore also increase the friction between the boat and the water. For this reason, the shaping of these guides is an important element in the success of the technical solution.

Inclination of a boat, particularly when turning, can allow the flow access to the wrong side of a flow guide and cause an awkward situation with regard to the balance of the boat. For this reason, the placement and adjustment of flow guides are important for ensuring the boat is at each moment steerable, controllable, and balanced. Another problem with what is known in the art is that installation of guide elements, trim tabs and lifting strakes necessitates making holes in the hull of the boat and often below the waterline. In addition, adjustment of lifting strakes integrated into the hull is impossible. Correspondingly, the adjustable trim tabs often used on boats increase the friction encountered at their operating location. Another problem with prior art is that the flow guides affecting the attitude of the boat and reducing friction are difficult to retrofit to the hull of the boat and boats of different brands also require their own types of fastening methods and fixing locations. Fastening to the hull usually necessitates drilling new installation holes in the hull of the boat. AIM OF THE INVENTION

The aim of this invention is to eliminate the aforementioned drawbacks and to provide an arrangement and a support structure, i.e. jointly a solution, that reduces the water resistance acting on a boat, thereby getting the boat to behave in a more stable manner and to rise into planing mode more easily. At the same time this also reduces the fuel consumption of motorboats. Another purpose of the present invention is to provide a solution that enables the easy and reliable fastening of a structure reducing the water resistance acting on a boat onto e.g. a boat provided with an outboard motor. One aim of the invention is also to provide an arrangement wherein a support structure reducing the water resistance acting on a boat is easy to install on the boat, and is also easy to retrofit. Yet another aim is to provide an arrangement wherein the support structure reducing the water resistance acting on a boat is easy to adjust to be suitable for different boats and which arrangement can be adjusted also while under way, with an outboard motor power lift possibly on the boat, to be suitable for different boating conditions . The arrangement according to the invention is characterized by what is disclosed in the characterization part of claim 1. Correspondingly, the support structure according to the invention is characterized by what is disclosed in the characterization part of claim xx. Other embodiments of the invention are characterized by what is disclosed in the other claims.

BRIEF DESCRIPTION OF THE INVENTION

The arrangement according to the invention comprises a support structure, with guide elements reacting to the flow of water, the structure to be fastened to the stern of a boat. The fastening of the support structure utilizes the standardized fixing holes for an outboard motor and a power lift possibly in the boat for optimizing the attitude of the guide elements. In addition to that, the guide elements to be used in the arrangement according to the invention are shaped to give directional stability and to maintain their load carrying capacity also when the boat inclines.

The arrangement according to the invention can be used e.g. in a boat comprising a transom and provided with an outboard motor. Preferably the arrangement comprises a support structure provided with guide elements acting on the water, which support structure is arranged to be fastened between the outboard motor and the transom of the boat. Preferably the support structure is fastened between the outboard motor power lift fastened to the stern of the boat and the outboard motor.

In the support structure according to the invention are fixing holes for fastening the support structure into position on the boat. Preferably the distribution of the fixing holes is the same as the distribution of the fixing holes of the outboard motor.

ADVANTAGES OF THE INVENTION

Some advantages, among others, of the solution according to the invention are the ease of installation, adjustability for different boats and different load states, and adjustability during travel. Owing to its adjustability, the solution according to the invention is operationally reliable and enables minimization of the water resistance acting on the boat in all load situations, in which case rising to planing mode is easier and fuel consumption decreases. This enables a smaller motor for the boat for achieving the same power. One advantage also is that the stability of the boat improves in all conditions. It is also an advantage that in the solution according to the invention there are extensive possibilities for adjusting the guide elements of the support structure that meet water, and the attitude of the guide elements can easily be adjusted with the power lift for the outboard motor also when under way. In addition, the shape of the guide elements can easily be changed to be specific to the boat by changing the wing. With the support structure according to the invention, obtainable as an accessory, a boat that originally is sluggish in the water can be manipulated to move lightly. In such a case it is easier for a boat that is sluggish in the water to rise into planing mode when the friction is reduced due to the optimization of its attitude in travel.

LIST OF FIGURES In the following, the invention will be described in greater detail by the aid of some embodiments and by referring to the simplified and diagrammatic drawings attached, wherein

Fig. 1 presents a simplified rear view of one preferred support structure, with guide elements, according to the invention, to be fastened onto the stern of a boat,

Fig. 2 presents a rear view of the frame part of the support structure according to Fig. 1,

Fig. 3 presents a rear view of another frame part of the support structure according to the invention,

Fig. 4 presents a magnified rear view of one guide element of a support structure according to the invention,

Fig. 5 presents a rear view of one support structure according to the invention fastened between the stern of a boat and the outboard motor, Fig. 6 presents a rear view of one support structure according to the invention fastened between the outboard motor power lift on the stern of the boat and the swivel bracket of the outboard motor, Fig. 7 presents an oblique view, from the rear and side, of one support structure according to the invention fastened between the stern of a boat and the outboard motor, and Fig. 8 presents a side view of one support structure according to the invention fastened between an aft platform at the stern of a boat and the outboard motor.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 presents a simplified rear view of one preferred support structure 1, with guide elements 5, according to the invention, the support structure to be fastened onto the stern of a boat. Preferably the support structure 1 can be installed e.g. on the stern or stern section of a motorboat provided with an outboard motor. The support structure 1 comprises a frame part 2, adjustment arms 3 fastened to its ends, and a guide element 5 fastened to each adjustment arm 3.

Fig. 2 presents the frame part 2 of the support structure according to Fig. 1 as viewed from the rear. Preferably the frame part 2 comprises e.g. a support arch 2b, which can be e.g. a flat bar, opening downwards in its operating position that is essentially symmetrical and bent into an arch. The frame part 2 is strengthened with a first reinforcement element 6 and a second reinforcement element 7, that are essentially parallel to each other and at a distance from each other. Preferably the reinforcement elements 6 and 7 are e.g. flat bars that are fastened at their ends, or near their ends, to the support arch 2b. In each of the reinforcement elements 6, 7 are at least two fixing holes 8 for fastening the frame part 2 to its fixing point on the stern section of the boat 10. At both ends of the support arch 2b of the frame part, which ends point obliquely downwards in the operating position of the support structure 1, is an adjustment area 2c in which is a plurality of fixing holes and adjustment holes 2a consecutively in a row that are presented better in Figs. 4, 6 and 7.

Fig. 3 presents another frame part 2 of the support structure 1 according to the invention, as viewed from the rear. This structure is preferably otherwise similar to the frame part 2 presented in Fig. 2, but now the top part of the frame part 2 is open. In this case at both ends of the reinforcement elements 6, 7 is only a support element 2d at least the length of the adjustment area 2c, which support element can be e.g. a short, arched flat bar or also a straight flat bar or some other element suited in cross- sectional shape for the purpose. In such a case the support element 2d can be e.g. a square hollow section and the adjustment arm 3 can be a square hollow section smaller in cross-section to be situated inside the support element 2d. The support element 2d is preferably disposed in such an attitude that the attitude of the support element 2d in the operating position of the support structure 1 guides the attitude of the adjustment arm 3 obliquely downwards and outwards.

In the frame part 2 according to Fig. 3 there are in total at least four fixing holes 8 for fastening the frame part 2 to its fixing point on the stern section of the boat, which fixing holes are similar to those in the frame part 2 according to Fig. 2. Likewise, in the support elements 2d of the frame part 2, which elements point obliquely downwards and outwards in the operating position of the support structure 1, is an adjustment area 2c according to what is described above in which is a plurality of fixing holes and adjustment holes 2a consecutively in a row. The frame part 2 according to Fig. 3 is easy to fasten between the swivel bracket 9a of the outboard motor 9 and the outboard motor power lift 11 because the top part at its center is open and therefore does not detrimentally collide with e.g. the structures of the power lift 11.

Instead of the two reinforcement elements 6, 7 on the frame part 2 there can be only one plate-shaped reinforcement element, wider than the reinforcement elements 6, 7, in which case there can be more holes 8 intended for fixing the frame element 2 than the standard four holes, thus there can be e.g. six holes. Fig. 4 presents a magnified rear view of one guide element 5 of a support structure according to the invention. The guide element 5 is fastened to the first end of the adjustment arm, i.e. to the bottom end of the adjustment arm 3 in its operating position, by means of fastening means suited to the purpose. At the second end of the adjustment arm 3 to be fixed to the frame part is a plurality of fixing holes and adjustment holes 3a in a consecutive row, the size and distribution of said holes corresponding to the fixing holes and adjustment holes 2a of the frame part 2. Preferably the adjustment arm 3 is fastened by means of the fixing holes and adjustment holes 2a, 3a on top of and overlapping the adjustment area 2c at the end of the frame part 2 with at least two fastening means 4, such as a screw-nut combination.

Since the end of the frame part 2 in the joint area between the frame part 2 and the adjustment arm 3 is directed obliquely downwards in the operating position of the support structure 1, adjustment of the location of the guide elements 5 has the effect that when lowering the guide elements 5 downwards they simultaneously displace outwards to the side. The horizontal distance between the guide elements 5 then increases. Correspondingly, an adjustment that lifts the guide elements 5 upwards also decreases the horizontal distance between them.

In addition to the placement location of the guide elements 5, the shape of the guide elements 5 also has an effect on the behavior of the boat. As viewed from the rear in the travel direction of the boat, as is presented in Fig. 4, the outer edge of the guide element 5, i.e. the first edge 5a, is arranged to point upwards, preferably essentially vertically upwards. The next, i.e. the first inner section 5b, is arranged to rise gently upwards in its operating position going towards the second edge 5e of the guide element 5. After this, the next, i.e. the second inner section 5c, is arranged to descend going towards the second edge 5e of the guide element 5 and the next, i.e. third inner section 5d, is arranged in its operating position to go first essentially horizontally and to curve after that downwards towards the second edge 5e of the guide element 5. Finally the second edge 5e, i.e. the inner edge, of the guide element is arranged to point downwards, preferably essentially vertically downwards. When the guide element 5 is in its operating position, the point of convergence of the third inner section 5d and the second edge 5e is preferably lower than the outer edge 5a of the guide element 5 and lower than the sections 5b and 5c.

The essentially vertical edges 5a and 5e of the guide elements 5 are arranged to increase the directional stability of the boat and to prevent the formation of water splashes and diving of the guide elements 5, as well as to enable retention of the water flow within the zone affected by the guide elements 5.

Additionally, the shape of the guide elements 5 is arranged to contract the flow of water below the guide elements 5, in which case the lift increases and the boat rises upwards, and the stern of the boat does not drag from below. The length of the guide elements 5 in the direction of travel of the boat affects the load carrying capacity of the guide elements 5. Lengthening a guide element 5 in the direction of travel of the boat produces more lift, in which case a heavy and slower-moving boat can be made to travel in a suitable attitude. The guide elements 5 are also arranged to be easily changeable, e.g. according to the load or type of the boat, when just adjustment of the location is insufficient.

Figs. 5-7 present a rear view of one support structure 1 according to the invention fastened between the transom 10a of the boat 10 and the outboard motor 9. Fig. 6 presents the fastening according to Fig. 4, magnified for the sake of clarity and with both the boat and the outboard motor removed from the figure. Fig. 7 presents one arrangement according to the invention as viewed obliquely from the rear and from the side.

In the solution according to Figs. 5-7 a power lift 11 moving the outboard motor 9 in the height direction is fastened to the flat stern, i.e. transom, 10a of the boat, to which power lift the outboard motor 9 is fastened e.g. via a swivel bracket 9a. For this purpose, there are fixing holes 9b in the swivel bracket 9a for fixing bolts 12. The swivel bracket 9a is a joint part of the outboard motor 9, which connects the outboard motor 9 as an outer part of the assembly.

The support structure 1 according to the invention is fastened by the flat-shaped reinforcement elements 6 and 7 of the frame part 2b between the swivel bracket 9a and the power lift 11. Preferably the location, size, and distribution of the fixing holes 8 in the reinforcement elements 6, 7 correspond to the location, size, and distribution of the fixing holes 9b of the swivel bracket 9a, which in turn correspond to the location, size, and distribution of the fixing holes in the power lift 11. In this case the support structure 1 according to the invention can be easily fastened between the outboard motor 9 and the power lift 11 for the outboard motor with the same fixing bolts 12 with which the outboard motor 9 is fastened to the power lift 11. This solution enables adjustment of the height of the guide elements 5 to be made also while under way by means of a power lift 11 for the outboard motor.

If a power lift 11 is not used in the fastening solution of the outboard motor 9 and the outboard motor is fastened by the swivel bracket 9a in the normal manner to the transom 10a of the boat, the support structure 1 according to the invention is fastened between the transom 10a of the boat and the swivel bracket 9a of the outboard motor 9 in the manner presented above with the same fixing bolts 12 with which the swivel bracket 9a of the outboard motor is fastened to the transom 10a of the boat.

Fig. 8 presents a side view of one support structure 1 according to the invention fastened by its frame part 2b between an aft platform 13 at the stern of the boat and the outboard motor 9. In this solution the aft platform 13 is a part of an enclosure-like cassette structure 14, which can function as e.g. a pontoon float, which is disposed behind the boat outside the transom 10a of the boat to improve the lift acting on the boat and to form a mounting base for the outboard motor 9. Preferably the rear wall of the cassette structure 14 is reinforced in such a way that it endures the fastening of the power lift 11 and outboard motor 9, and the stress produced by them. The outboard motor 9 and the support structure 1 are fastened to the outboard motor power lift 11 in the same way as already described in the preceding. This solution enables the guide elements 5 to be farther in the horizontal direction from the transom 10a of the boat than in the solution described in the preceding. In this case the guide elements 5 can have a greater effect on the stability of the boat, on its planing characteristics and on its other behavior.

Preferably the guide elements 5 are disposed at an angle of approx. 20 degrees with respect to the travel direction of the boat 10 in such a way that the front edge of the guide elements 5 is higher than the rear edge. When the boat is under way, the height of the guide elements 5 in relation to the boat 10 is adjusted by means of the power lift 11 in such a way that the guide elements 5 hit the water only with their bottom surface at an angle of approx. 10-30 degrees with respect to the water flow. Preferably the angle is approx. 20 degrees. The guide elements 5, more precisely their front edges, are at a distance of approx. 10-60 cm to the rear of the transom 10a of the stern of the boat 10. Suitably the distance is e.g. between 20-50 cm, preferably e.g. between 30-40 cm. By means of the fixing holes and adjustment holes 2a of the frame part 2 of the support structure 1 and the fixing holes and adjustment holes 3a of the adjustment arms 3 the horizontal distance between the guide elements 5 is adjusted in the sideways direction preferably in such a way that the guide elements 5 are situated inside the extensions formed by the flanks of the boat 10 and in the height direction the location of the guide elements 5 is adjusted in such a way that preferably at least the front edge of the guide elements 5 is above the bottom 10b of the boat. Preferably the height adjustment is performed with a power lift 11 for the outboard motor in such a way that the flow of water is made to stay below the guide elements 5. It is obvious to the person skilled in the art that different embodiments of the invention are not limited to the example described above, but that they may be varied within the scope of the claims presented below.