STRUCTURE OF STERN OF A WATERCRAFT WITH SWIMMING PLATFORM

DESCRIPTION

Field of the invention The present invention relates to the field of recreational watercrafts, and more in detail it relates to a structure of stern of a watercraft having a swim platform or swim deck, which is adapted for users who wish to stay on it, or who wish to descend or to plunge into water or go back up the watercraft after a swim, or also to go on board a rubber boat or tender during stops of a trip .

Description of the prior art

Many recreational watercrafts have a swimming platform or stern platform connected to the transom as a protruding bracket with a ladder. Other types of watercrafts have, instead, the swimming platform integrated to the hull.

In the latter case, in some types of less elevated watercrafts, for example as disclosed in US4548155, the swimming platform is integral to the stern. Watercrafts having this type of swimming platform can be for example planing motorboats even of large size.

In more elevated watercrafts, always with swimming platform integral to the stern, such as US5572944, stairs can be provided for descending from the deck to the swimming platform. In case of fixed stern platforms, in any case, there is the drawback that the swimming platform is located at a height that cannot be lower than the transom of the watercraft, with an inconvenience for the user when going back up after a swim.

To overcome this disadvantage, as described in WO02051698, an abutting swimming platform, movable from a first higher position to a second lower position, can be provided. The relative lowering can be carried out between a movable part, exteriorly abutting as a swimming platform, and a fixed part, integral to the stern of the watercraft. In this case, the swimming platform can be lowered to a lower position of the transom, up to result just above or just below the water surface.

Some types of watercraft, in order not to change the aesthetic appearance of the stern region, especially sail yachts of average or large size, can have the stern with a swimming platform that is concealed, obtained by tilting or drawing out a part of the transom, to make a protruding platform that can be used a swimming platform, for example as described in EP2152567.

In some cases, the operation of tilting the transom uncovers a staircase located underneath, as it often occurs for example in sail yachts of medium and large size, to allow an easy descent from the deck to the swimming platform. Such solution requires very heavy tilting arms, which affect substantially the weights for balancing the watercraft. In any case, in the configurations that tilt a platform from the transom have the drawback of limiting the descent to the water surface, because the platform remains normally at the height of the lowermost point of the transom, which in some yachts of larger size is rather high. Therefore, from the platform a further ladder with several steps is required for going back up on the watercraft after a swim.

Furthermore, this type of tiltable platforms requires a specific design and construction and is adapted for new watercrafts, whereas with existing watercrafts it does not allow retrofit installations without substantial re ^¬ construction of the hull.

Summary of the invention It is then a feature of the present invention to provide a structure of stern of a watercraft that provides a swimming platform completely concealable and that is structurally easy.

It is another feature of the present invention to provide such a structure of stern of a watercraft that is as far as possible light in order not to change substantially the balancing of the watercraft.

It is also a feature of the present invention to provide such a structure of stern of a watercraft that is easily implemented as retrofit in existing watercrafts.

These and other objects are achieved by a structure of stern of a watercraft, comprising: - a fixed part comprising a stern portion of the watercraft, the fixed part having a first staircase portion and a guide;

- a movable part having a second staircase portion, the movable part arranged to slidingly engage with the guide, in order to move with respect to the fixed part between a first raised position in which the movable part covers the first staircase portion of the fixed part, and a second lowered position in which the movable part uncovers the second staircase portion of the fixed part;

- a platform pivotally connected to the movable part, and arranged to move between a first position in which the platform covers the second staircase portion, and a second position in which the platform can be moved following a horizontal plane protruding from the movable part opposite to the watercraft, in order to form a swimming platform or swimming deck.

With respect to the prior art, as it is common in sail yachts of medium and large size, in which the platform is pivotally connected to the fixed part of the stern, the solution according to the invention of a platform pivotally connected to the movable part, allows lightening remarkably the fixed part and reducing then completely the weight and the subsequent unbalance of the watercraft due to the presence of the mechanism for tilting the platform.

The fact of lowering slidingly the movable part along with the platform, allows, moreover, achieving a total closure of the region of stern in such a way to appear exteriorly as a transom substantially identical to a watercraft without swimming platform, contrarily to the swimming platform fixedly protruding from the stern of WO02051698.

Advantageously, the fixed part has a central recess with which the movable part engages, the platform having an outer face, and a lower portion of the movable part protruding from the second staircase portion, so that the fixed part, the outer face and the lower portion form a transom substantially planar when the movable part and the platform are in their respective first position.

Also this feature allows not to alter the aesthetic appearance of the stern region of the watercraft, since it does not provide any protruding portions when the watercraft is in navigation and the transom is identical to watercrafts that do not have swimming platform at all.

Preferably, the first staircase portion has a plurality of stairs, and the movable part has an upper stair, the movable part, when moving from the first to the second position, configured to stop at a plurality of intermediate positions where the upper stair is coplanar to each stair of the first staircase portion of the fixed part .

This way, the platform can be lowered and arranged at each intermediate positions where the alignment between the upper stair of the movable part and any of the stairs of the fixed part occurs.

Advantageously, the fixed part has a coupling interface arranged opposite to the movable part, the coupling interface configured to be connected to the transom of an existing watercraft.

This way, the fixed part, with the movable part and the platform pivotally connected to the latter, can be applied as retrofit to any existing watercraft.

Advantageously, the coupling interface is at a predetermined angle with respect to the stairs of the first and second staircase portions, in order to couple to a slanting transom of existing watercrafts. This way, the structure of stern according to the invention can be applied as retrofit to the transom, sometimes slanted, of existing watercrafts, for example sail yachts.

Advantageously, the fixed part provides a protruding box which contains an extensible gangway, the second staircase portion having a housing in which the box engages when the movable part is in the first position, and the platform having a rotatable wing that, when the platform is in the first position, opens a recess in which the box engages when the platform is in the first position, whereas when the platform is in the second position the wing covers the recess allowing the user to walk on all the platform.

This way, when the movable part and the platform are in the first position, they fit to the shape of the box for the gangway and all the transom is coplanar. A cover can be provided for closing the box when the gangway is all retracted inside, where the cover is coplanar to the remainder of the transom.

Brief description of the drawings

The invention will be now shown with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings in which:

- Fig. 1 diagrammatically shows a perspective view of a structure of stern of a watercraft according to the invention in a position in which the transom is closed by a substantially continuous surface;

- Fig. 2 is an elevational side view of the structure of stern in the position of Fig. 1;

- Fig. 3 diagrammatically shows a perspective view of the structure of stern of Fig. 1 in an operative position with rotated platform;

- Fig. 4 is an elevational side view of the structure of stern of Fig. 3 with rotated platform;

- Fig. 5 diagrammatically shows a perspective view of the structure of stern of Figs. 1 and 3 in an operative position with rotated platform and lowered movable part of the staircase;

- Fig. 6 is an elevational side view of the structure of stern according to the invention in the position of Fig. 5;

- Fig. 7 diagrammatically shows a perspective view of an exemplary embodiment with extensible gangway of the structure of watercraft stern in a position in which the transom is closed with surface substantially continuous and with retracted gangway;

- Fig. 8 diagrammatically shows the structure of stern of Fig. 7 with transom closed and with gangway extended;

- Fig. 9 diagrammatically shows the structure of stern of Fig. 7 in an operative position with rotated platform and gangway retracted, similar to that of Fig. 3;

- Fig. 10 diagrammatically shows a perspective view of the structure of stern of Fig. 7 in an operative position with rotated platform, with movable part of the staircase lowered and gangway retracted, similar to that of Fig. 5.

Detailed description of some exemplary embodiments

As diagrammatically shown in Figs. 1 to 6 a structure of stern 1 of a watercraft comprises a fixed part 10 having a transom portion 11 and a side wall portion 12 comprising a stern portion of the watercraft, with a deck portion 18 in continuity with the deck of the watercraft.

The watercraft is not shown for simplicity, and it can be any sail yacht or to motor yacht, planing or displacing watercraft. For example, the invention is applicable to sail yachts with medium-large size and any sail configurations, for example, Ketch, Yawl, Sloop, Shooner, etc .

The structure of stern 1 can be integral part of the watercraft already at the construction, or it can be applied as retrofit in a later time. In case of application already starting from the construction, the structure of stern according to the invention can be supplied to the manufacturer as a prefabricated custom kit .

The side wall portion 12, especially in case of retrofit, can have then a line/interface surface 13 opposite to the transom portion 11, with a slanted line which can also be corresponding to that of the transom of the watercraft to which it will be applied, which in many yachts is often a very pronounced slanting.

As shown in particular in Fig. 5, fixed part 10 has the transom portion 11 discontinued by a substantially rectangular recess 14, in which a first staircase portion 15 is made, integral to fixed part 10.

In the recess 14 a guide not shown is made that allows sliding a movable part 20 having a second staircase portion 21. In particular, the movable part has an encumbrance substantially the same as the recess 14 of fixed part 10 and can engage with it, in order to move from a first raised position, visible in Figs. 3 and 4, in which the staircase portion 21 of movable part 20 covers the first staircase portion 15 of the fixed part, to a second more lowered position, visible also in Figs. 5 and 6, in which movable part 20 uncovers the second staircase portion 15 of the fixed part. In particular, the movement can be a sliding movement on guides, or also a movement equivalent obtainable with articulations of known type, or a combination of such two arrangements.

Always in a way not shown, actuators of the movement of movable part 20 with respect to fixed part 10 are provided along the guide. The guide and the sliding movement actuators are not shown since easily implementable by a skilled person, for example by pistons or chains, hydraulic, mechanical or mixed.

In Figs. 1 to 6 a platform 30 is shown that is pivotally connected to movable part 20 by means of hinges 31 and actuators of the rotation 32. Platform 30 has an outer face 33, which forms the surface of the transom in Fig. 1, and an inner face 34, which it works as floor. Platform 30 has an encumbrance substantially the same as the recess 14 of fixed part 10 and can move, by the actuators 32 and hinges 31, which link it to movable part 20, from a first closed position, as shown in Figs. 1 and 2, in which platform 30 engages with a concealed recess 14 and covers second staircase portion 21, to a second rotated position, as shown in Figs. 3 to 6, in which platform 30 can be moved following a horizontal plane protruding from movable part 20 opposite to the fixed part and to the watercraft, in order to form a floor, commonly called swimming platform or swimming deck.

In the position of Figs. 3 and 4, in which movable part 20 is in the first more elevated position, platform 30 can move, in order to change the position of the floor consisting of face 34, similarly to some tilting platforms of the prior art. In the position of Figs. 5 and 6, in which movable part 20 is in the second more lowered position, platform 30 can then move to a position very close to the water surface.

The swimming platform comprising platform 30 can, in this case, be located at a height that is partially submerged or that can receive water from the waves, with pleasant utility for guests of the watercraft for example in a lake or sea with calm water, similarly to a real beach .

Owing to the solution of platform 30 pivotally connected to movable part 20, fixed part 10 has been remarkably lightened, since it consists substantially of a short end side wall section of the watercraft. Platform 30 and movable part 20 do not have components that involve a particular increase of weight for all the structure of stern 1 according to the invention.

The application as retrofit to the watercraft increases not much the tonnage, since recess 14 is oriented outwards, and does not introduce a substantial unbalance to the watercraft, owing to the lightness of the mechanism for operating the rotation of platform 30 consisting of actuators 32 and hinges 31. The fact of lowering slidingly on fixed part 10 the movable part 20, along with platform 30, determines a total closure of the transom in the first position, in order not to present protruding portions when the watercraft is in navigation, with a transom identical to watercrafts that do not have a stern swimming platform, as many existing sail yachts.

The first staircase portion 15 of fixed part 10 can have a plurality of stairs that are gradually uncovered by movable part 20 when the latter is moved below towards the second position. The movable part has an upper stair 21a of second staircase portion 21, and when moving from the first to the second position, can stop at a plurality of intermediate positions at which the upper stair 21a is coplanar to each stair of the first staircase portion 15 of fixed part 10. For example, if the first staircase portion 15 of fixed part 10 has eight steps that can be uncovered by movable part 20, then movable part 20 can be located at eight possible different heights from the water surface, between the raised position of Figs. 3 and 4, in which the upper stair 21a is coplanar to the deck portion 18, up to the lower position of Figs. 5 and 6, in which the upper stair 21a is coplanar to the lowest stair of first staircase portion 15.

The user can then easily reach the swimming platform which comprises floor 34 by descending all the first staircase portion 15, on all the number of uncovered stairs, starting from the upper stair 21a, in which the stair width is double, and then descend all the stairs of second staircase portion 21.

In order to provide upper stair 21a, movable part 20 can have a lateral profile that is parallel to the recess 14 of fixed part 10, as shown in the side views of figures 2, 4, 6, so that movable part 20 can slide towards below.

Lower portion 25 of movable part 20 protrudes from second staircase portion 21, and it can be external to the recess 14 of fixed part 10. This way, the transom can comprise transom portion 11, the outer face 33 of platform 30 and lower portion 25, when movable part 20 and platform 30 are in their respective first position, i.e. raised and closed .

In the lowered position of movable part 20, lower portion 25, which can provide hinges 31, can sink below water level 40, since it is located below platform 30.

As shown in Figs. 7 to 10, in an exemplary embodiment of the invention, from fixed part a box 16 protrudes, for housing an extensible gangway 50. In order to fit box 16, second staircase portion 21 has a recess 26 in which box 16 engages when movable part 20 is in the first position.

Also platform 30 can have an opening 36 closed by a rotatable wing 37 that, when the platform is in the closed first position (Fig. 7), it can move against surface 34 releasing opening 36, so that box 16 engages with it. Instead, when the platform is in the lowered second position, wing 37 can rotate 180° and covers opening 36 allowing the user to walk on all the surface 34 of platform 30. Other arrangements of the wing 37, or the provision of different closure member for opening 36 are obviously possible and easily found by a skilled person.

A cover 17 can be provided for closing box 16 when the gangway 50 is all retracted inside, that is coplanar to the remainder of the transom 11 and to the outer face 33 of platform 30, so that when movable part 20 and platform 30 are in the first position of Fig. 7, they fit the shape of box 16 in such way that the whole transom has continuous surface.

The foregoing description of specific exemplary embodiments can show the invention from a conceptual viewpoint so that other, by applying current knowledge, will be able to modify and/or adapt in various applications the specific exemplary embodiments without further research and without parting from the invention, and, accordingly, it is meant that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to perform the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.